Chest radiology 1

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Normal Chest

Oblique views : retrocardiac area, post. costophernic angles & chest walls.

AP view : ribs are projected over different areas of lung from those of PA + post chest

wall is shown.

Appicogram: A.Apical view : Pt leans back, AP projection & tube angled 50-60

upward (projection of clavicles up).

B.Lordotic view : PA view, Pt leans back, (project clavicles,also done in

cases of middle lobe collapse.

Paired :Insp. & exp. film.

1. Demonstrates air trapping

2. Diaphragm movement.

3. Small pneumothorax.

4. Interstitial shadowing.

Penetrated film :

1. To show the hidden areas.

2. Demonstration of rib destruction.

3. Cavitation or calcification.

4. Air bronchogram demonstration.

Comment on plain film:

I. Posteroanterior view :

1. Criteria of good quality film:

Centralization: med ends of clavicles = distance from spine t4

Full inspiration: ant 6th rib, post 10th rib .

Penetration: bodies, discs just visible through cord shadow upper 3rd only.

2. Trachea :

Examined for (narrowing, displacement, intraluminal lesion).

Normally, it is midline in its upper part, then deviates slightly to the right around

the aortic knuckle.

NB: *Right paratracheal strip:

- On the right side, the tracheal margin can be traced down to the right main

Chest radiology 2

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bronchus. It is present on 60% of films. Normally, it measures less than 5 mm.

Widening occurs with (tracheal malignancy, mediastinal tumors, pleur.effusion)

Azygus vein :

-Lies in the angle between the right main bronchus and trachea.

-Enlarged in (supine position, portal hypertension, I.V.C & S.V.C obstruction,

constrictive pericarditis).

- On erect film, should be < 10mm.

Carinal angle on inspiration is 60-75 degree.

Pathologically enlarged in a. Enlarged left atrium.

b. Enlarged carinal L.N.

3. Heart and mediastinum :

comment on size, shape, and displacement.

4. Diaphragm :

-Outline, shape, position.

-The right hemidiaphragm is higher than left (due to heart pushing on the left side

and not due to liver elevating the Rt), a difference greater than 3cm is significant.

The right hemidiaphragm can be traced from anterior to posterior on the lateral film, while the

left cannot.

-Loss of outlines means that the adjacent lung contains no air.

-On inspiration, the domes are at level of : * 6th rib anteriorly

* below or at 10th rib posteriorly. .

5. Pleura :

-Position of horizontal fissure. (The horizontal fissure runs from the hilum to region

of 6th rib).

-Costophrenic and cardiophrenic angles.

On lateral film : The horizontal fissure runs anteriorly.

Both oblique fissures, start posteriorly at the level of T4 or T5, passing through hilum.

- The left fissure finishes 5cm behind the anterior costophrenic angle, the right ends

Subpulmn. pleural effusion :

1. Erect PA : elevation of diaphragm & the apex of effusion has a more lat. position

2. Supine film : - Opaque hemithorax with decrease visualization of pulm vs.

- Blunt costophrenic angle.

- Apical cap.

- Loss of diaphragm out line

3. Decubitus view with horizontal beam : fluid level along the affected side.

Chest radiology 3

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6. Lung fields :

Hidden areas :(apices, diaphragm, mediastinum, hilae and bones).

7. Hilum :

Shape, position, density :

-Normally the left hilum is 1/2-1cm higher than right (because left pulm.a. lies above

the left main bronchus before passing post.)

-They should be of equal density and size with concave lateral borders.

-Only the pulmonary arteries and upper lobe veins significantly contribute to hilar

* Ant junctioned line: is where the lungs meet anterior to the ascending aorta. It is only 1 mm thick

(from below suprasternal notch).

* Post junctional line : is where the lungs meet posteriorly behind the esophagus. It is 2mm thick

(from

lung apex to level of knuckle).

* Thymus : both borders may be wavy (sign of Mulvey) dt costal cartilage indentation. It is sail

shaped, right border more straight male >female.

* Main fissures : (tangential x-ray beam)

1. PA : horizontal fissure runs from hilum to 6th rib in axillary lines may be slight down curve.

2. Lat : All fissures : oblique fissures commence post from D4 or D5 passing through ! hilum, !

left is steeper & finishes 5cm behind ! ant costophrenic angle.

* Accessory fissures :

1. Azygous fissure : comma shaped, base & nearly always rt sided (failed azygous v. to

migrate). Left side hemiazygous vein.

2. Superior accessory fissure : separates !apical from basal segments of lower lobes.

3. Inferior accessory fissure : separates ! medial basal from the other basal segments (from

cardio

phrenic angle).

4. Left sided horizontal fissure : separates lingula from other upper lobe segments.

Hidden areas :

1. Apices: appicogram.

2. Mediastinum and Hila: lateral film (for central lesions).

3. Diaphragms: post.& lat. basal segments of lower lobes & ! post. sulcus are partially observed.

4. Bones: AP, expiratory film & obliques - Tomography.

Chest radiology 4

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shadows.

-The maximum diameter of normal descending branch of the right pulmonary

artery is 10-16mm in males, and 9-15mm in females.

-In erect position, the lower lobe vessels are larger than the upper lobe vessels as

the perfusion and areation of the upper zones are reduced.

-The pulmonary arteries accompanying the bronchi, while the veins :

a. Have fewer branches.

b. Less defined and larger.

c. Do not follow the bronchi.( They follow (drain via) interlobular septa)

* Upper lobe bronchus may appear as a ring shadow adjacent to upper outer hilum.

Pulmonary segments & bronchi :

8. Bronchial vessels :

-Normally not visualized on film.

-The arteries arise from ventral surface of the descending aorta at the level T5-T6.

-Enlarged bronchial arteries, appear as multiple small nodules around hilum.

Cause of enlargement :

* General (congestive cyanotic heart disease).

* Local (bronchiectasis, primary carcinoma).

Lymph nodes :

* Intrapulmn lymphatics drain to bronchopulmn node (1st group involved by spread from a periph.

tumor).

* Mediastinal Lns (may be involved by tumors above or below the diaphragm).

1. Ant. mediastinal nodes: (drain thymus & Rt heart - in region of aortic arch.).

2. Intrapulmn. nodes : along main bronchi.

3. Middle mediastinal nodes (lung, bronchi, lt ht, lower trachea & visceral pleura)

a. Bronchopulmn (hilar), drain into.

b. Carinal

c. Tracheo bronchial (Rt - adjacent to azygous , Lt - near RLN).

d. Paratracheal

4. Post mediastinal nodes : drain post diaphragm & lower oesophag. lie around lower descending

aorta & lower oesoph.

5. Parietal nodes: (ant & post behind sternum) ,drain soft tissue & parietal pleura (also intercostal

region).

Chest radiology 5

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9. Pulmonary segments and bronchi (see Sutton)

-Pulm. segments not separated by pleura. Normal bronchi are not visualized in periph lung zones.

10. Acinus : (functioning lung unit).

-Is that portion of lung which arises from the terminal bronchiole.

-When filled with fluid, it is seen as a 5mm shadow = acinar or alveolar shadowing.

-The pores of Koha, connect the alveoli. The canals of lambert exist between

bronchioles and alveoli.

11. Below diaphragm : (Gas shadow, calcification)

-Chialiditis syndrome : Interposition of bowel between liver and diaphragm (often

transient).

12. Soft tissue :

-Mastectomy, Poland syndrome (cong absent pectoral ms), nipple shadows.

-Companion shadows : 2-3 mm thick // to upper clavicles & inf border of ribs.

13. Bones : (Clavicles, scapula, ribs, spines).

II. Lateral Film : Comment on the following :

1. The clear spaces: (retrosternal, retrocardiac).

-Normally, the retrosternal space measures less than 3cm at its widest point.

2. Vertebral translucency :

-The vertebral bodies become progressively more translucent caudally.

Loss of this translucency (Posterior basal consolidation, Para Vertebral mass).

3. Diaphragm outlines :

-Loss of the outline (pleural effusion, consolidation).

4. Pulmonary arteries :

-The left pulmonary artery lies above& posterior to end on carina, the right lies and

in front.

5. Others :

-Fissures (displacement, thickening, loculated interlobar effusion).

Chest radiology 6

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Differential Diagnosis

Krley’s Lines :

1. A-lines : Thin, non branching lines radiating from the hilum (2-5cm in length,

thick deep intercommunicating lymphatics, DD: blood vessels).

2. B-lines : -Transverse, thin line of 1-3cm.

-Seen at the base of the lung lying perpendicular to ! pleura (in costo-

phrenic angle).

-Formed by thickened interlobular septa (in lat film seen behind !

sternum () = D lines.

3. C-lines : A spider’s web appearance : interlacing lymphatics.

*Causes of visualization : (Lymphatic obst).

1.Pulmonary edema.

2.Mitral valve disease.

3.Pneumoconiosis.

4.Lymphangitis carcinomatosa unilateral kerly, Blues.

5.Lymphoma.

6.Alveolar cell carcinoma.

7.Interstitial fibrosis.

8.Sarcoidosis.

Silhouette Sign :

-It permits localization of the lesion on the PA view by studying the mediastinal and

diaphragmatic outlines.

-These outlines are visualized because the adjacent alveoli are aerated.

-If air is displaced, the adjacent borders are obliterated where the lesion is located,

conversely if the border is retained and the abnormality is superimposed, the lesion

must be either anterior or posterior e.g.:

* Lesions of the middle lobe (rt) and lingula (lt) affect the right and left

cardiac border.

* Obliteration of the aortic knuckle is a feature of disease in apico-posterior

Chest radiology 7

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segment of upper lobe (left).

* A well defined mass seen above the clavicle is always posterior.

The Hilum Overlap sign :

Helps to distinguish a larger heart from a mediastinal mass :

A mediastinal mass hilum is seen through mass.

Cardiomegaly hilum is displaced.

Air bronchogram :

An important sign. The bronchus if air filled and not fluid filled becomes visible,

when air is displaced from the surrounding alveoli (parenchyma).

*Causes :

1. Consolidation (Pneumonia, infarction, collapse, Pulm hge, TB).

2. Pulmonary edema.

3. H.M.D = Hyaline membrane disease.

4. Lymphona.

5. Alveolar cell carcinoma.

6. Sarcoidosis.

7. Adult respiratory distress syndrome.

N.B:

* An air bronchogram does not occur within pleural fluid or solid tumor.

* It may be present in consolidation distal to a malignancy if the bronchus

remains patent.

Alveolar or acinar shadowing :

-Fluid filled acinus that forms (4-10) 7mm shadow, rapidly coalesce into fluffy, ill

defined cotton wool shadows and homogenous mostly non segmental.

NB: *Air bronchogram and silhouette signs are characteristic features.

*Pulmn. Shadowing: alveolar(acinar),or interstitial.

-A ground glass appearance or a generalized homogenous haze seen with alveolar

shadowing may have a bat’s wing distribution, when a homogenous shadow

spreads, from hilae with a periph.translucent rim.(peripheral lung field spared, butterfly),

commonly due to cardiac failure and clears quickly after treatment.

Chest radiology 8

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Causes :

1. Pulmonary edema :

-Cardiac pulmn edema.

-Non cardiac (Uremia, hypoalbuminaemia, fluid overload).

2. Pneumonia :

-Localized : (pneumococcus).

-Generalized (fungi, parasites).

3. Neonatal :

-H.M.D

-Aspiration pneumonia.

4. Tumors :

-Lymphoma, leukemia.

-Alveolar cell carcinoma.

-Haematogenous metastasis (e.g. choriocarcinoma)

5. Alveolar blood :

-Pulmonary infarction, hematoma.

-Good pasture’s syndrome.

6. Miscellaneous :

-Radiation pneumonitis.

-Sarcoidosis.

Interstitial

Shadowing :

-Thickening of parenchymal perivascular tissue.

Causes of Consolidation = Air bronchogram = alveolar shadows

:

-Consolidation pneumonia, TB

-Pulm edema.

-Infarction.

-Hge

-Alveolar cell ca.

-Lymphom

-HMD, ARDS

Chest radiology 9

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-Radiologically appears as (reticular, nodular 2-3mm, reticulonodular, ground glass

shadowing).

-Kerley’s lines and honeycomb shadowing may be present.

-Loss of volume may occur as a result of fibrosis.

Causes of diffuse interstitial shadowing :

A. Infection : TB, Mycoplasma, viral, fungi, parasitic .

B. Cardiac : Left heart failure.

C. Neoplasm : Lymphoma, leukemia, lymphangitis carcinomatosa.

D. Collagen diseases : S.L.E., P.A.Nodosa, Rh arthritis, scleroderma.

E. Honey comb shadowing.

F. Miscellaneous:

-Fibrosing alveolitis.

-Extrinsic allergic alveolitis.

-Sarcoidosis, haemosiderosis.

-Bronchiectasis.

-Neurofibromatosis.

Causes of Miliary Shadowing : (multiple opacities (1/2-2mm)

A. of soft tissue density :

1. TB. 2. Sarcoidosis

3. Pneumoconiosis 4. Metastasis (renal, thyroid, trophoblastic).

5. H.M.D 6. Histoplasmosis

B. of high density :

1. Alveolar microlithiasis. 2. Calcification (TB).

3. Haemosiderosis, silicosis. 4. Tin or barium inhalation.

Honey comb shadowing :

IPF == Interstitial shadows

-Ext - allergic Drugs - Sarcoidosis. -ARDS -infection TB, viral, fungal.

-Silicosis - Histocytosis -fibrosing -cardiac LHF

-Asbestosis. - Tuberous sclerosis -Collagen - Bronchiectasis

- Neurofibromatosis. - Neoplasm lymphoma,

lymphangitis carcinomatosa

Chest radiology 10

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-Interstitial lung disease parenchymal destruction formation of thin wall cysts,

when these cysts are 5-10 mm = honey comb shadowing.

-It is associated with increased risk of pneumothorax.

Causes of honey comb shadowing :(= Causes of interstitial fibrosis + Bronchiectasis).

1. Histocystosis.

2. Collagen disorders (seleroderma, rheumatoid) mostly basal.

3. Pneumoconiosis .

4. Sarcoidosis.

5. Extrinsic allergic alveolitis (upper zone).

6. Biliary cirrhosis.

7. Neurofibromatosis.

8. Bronchiectasis (similar appearance).

NB: - Bronchiectasis + IPF = Honey comb

- Congenital polycystic lung

Solitary pulmonary nodule :

1-Malignant tumors :

-Bronchial carcinoma..

-Secondary: (cannon ball metastasis) “very large”.

-Calcified metastasis (osteo and chondrosarcoma)

-Lymphoma.

-Plasma cytoma.

2-Benign tumors :

-Hamartoma (90% peripheral)

-Adenoma.

3-Granuloma :

-TB./ Sarcoidosis

-Histoplasmosis.

4-Infections ::

-Pneumonia,

-Abscess( Klebseilla, staph)

-Hydatid.

-Mycetoma : fungal ball.

NB: Nodular form of Fungus: Histoplasmosis. Coccidomycosis, Actinomycosis, Mycetoma

Chest radiology 11

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(Aspergillosis)

5-Vascular :

-Pulmonary infarction.

-Hematoma. -AVM.

6-Collagen disease

-Rh. Arthritis.

7-Sarcoidosis.

8-Congenital :

-Sequestrated segment.

-Bronchogenic cyst.

9-Non Pulmonary :

-Skin lesion (lateral film helps to distinguish extra pulm masses:* Intrapulmonary mass has

acute angles with lung edge. *Extrapulmonary & mediastinal masses form obtuse angles.

-Bone lesion

-Pleura (encysted effusion, plaque)

-Artifacts.

Cavitation :

-Radiologically : A cavity is a translucency within the lung parenchyma surrounded

by a complete wall (thick : 3mm or more)

*Sites of predilection for certain pathologies :

-TB mostly upper lung zone, infraclavicular.

- Aspiration abscess mostly right side, lower zone.

- Amoebic abscess always in the right lower zone.

- Pulmonary infarction commonly lower zones.

- Sequestrated segment left sided.

*Comment on wall pattern :

- Malignant tumors thick irregular wall with eccentric cavitation.

*Comment on presence of fluid level.

Intracavitary bodies :

-Aspergillesis : mycetoma.

-Hydatid : disintegrated.

-Lung gangrene bl. clot in cavity.

-cavitary sq. cell carcinoma.

-simple lung abscess.

Chest radiology 12

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*Comment on content of cavity :

- Irregular masses of blood clots or necrotic tumor may be seen within cavity.

*Comment on satellite lesions ? : Are common with TB.

*Comment on surrounding lung tissue.

Causes of cavitation : (P77, same reasons as solitary nodule, but cavitation occurred, +

bronchietasis, bullae

A. Infection: Staph.(commonest), Klebsiella (abscess),TB, Amoebic, Hydatid, Fungal

(aspergillosis).

B. Malignant : Primary, 2ry, Lymphoma.

C. Aspiration abscess

D. Pulm, infarction, hematoma.

E. Pneumoconiosis : Caplan’s syndrome.

F. Cystic Bronchiectasis, sequst. lung, bronchogenic carc.

G. Sarcoidosis.

H. Bullae, pneumatocele - thin wall.

NB: Cong., trauma, inflam/inf/grannuloma, Neop., Vasc, others.

Causes of multiple cavities :

1. Abscesses 2. Lymphoma 3. Metastasis 4. Rheumatd nodules

Causes of fluid levels on chest Film:

1. Intrapulmonary cavitation

2. Hydropneumothorax

3. Esophageal (pharyngeal pouch, Achalasia)

4. Mediastinal (infection, esophageal perforation).

5. Pneumopericardium (trauma, aspiration).

6. Chest wall infection, fractures.

Thick wall cavity: Thin wall cavity:

1.Acute abscess 1.Bullae

2.Most metastases 2.Pneumatoceles

3.Most neoplasma (usually sq. cell) 3.Cystic Bronchiectasis

4.Lymphomas 4.Hydatid cyst

5.Wegener’s grannuloma 5.Traumatic lung cyst

6.Rheumatoid nodule 6.Carcinoma

7.Chronic inactive TB cavity.

Chest radiology 13

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7. Diaphragm hernia, eventration, rupture.

Calcification : (low KVP)

A. Intrapulmonary :

1. Granuloma, infections :

a.TB (commonest, m.imp), foci are in upper zone, scattered & of variable size.

b.Histoplasmosis characterized by focal areas surrounded by small haloes.

c.Hydatid cyst rarely (fine rim of calcification in wall).

d.Actinomycosis.

e.Chronic abscess

f. Chicken pox.

2. Tumors:

a.Metastasis (osteo, chondrosarcoma). c.A.V.M.

b.hamartoma (pop corn calcification). d.Carcinoid T.

3. Chronic pulmonary venous hypertension mitral valve disease.

4. Hematoma, infarction.

5. Alveolar microlithiasis: tiny sand like densities in mid and lower zone due to

calcium phosphate deposits in the alveoli.

6 Metastatic due to hypercalcaemia: Chronic renal failure, 2ry hyperparathy.,

M.Myeloma.

7. Rare causes as: Sarcoidosis, Silicosis (egg shell calcification).

B. Pleural : TB, asbestosis, empyema, talc, old haemothorax.

C. LN : TB, histo, sarcoid, silicosis, lymphoma after irradiation.

D. Mediastinal : cardiac, vascular, tumors.

NB:

* Ruptured hydatid cysts have daughter cysts floating within!cavity = water lily sign.

* Other intracavitary lesions include inspissated pus, blood clot & cavernoliths.

* Blood clots occur with cavitating neoplasm, tuberculosis & primary infarcts.

* Common in primary tumors, & irregular masses.

* Uncommon in cavitating metastases & TB cavities.

* Meniscus sign is when intracavitary body is surrounded by crescent of air,

commonly described with fungus balls such as aspergilloma, ! ball moves as : pt,

change position.

Chest radiology 14

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E. Pulm A : Aneurysm, P++, thrombus.

F. Chest wall : bone, breast, soft tiss., cartilage, parasites.

Causes of unilateral hypertransradiant hemithorax :

A. Rotation : (positional)

1. poor technique

2. scoliosis.

B. Chest wall :

1. Mastectomy.

2. Poliomyelitis (unilateral pectoral muscle affection).

3. Poland’s syndrome (Unilateral absence of pectoral muscles + rib defect with

syndactly) in 10% of patients.

C. Pleura :

Pheumothorax.

DD: Localized transradiancy : *Bullae. *Emphysema. *Cyst. *Encysted pneumothorax.

*Pneumatocele.

D. Lung :

1. Compensatory emphysema.

2. Obstructive emphysema.

3. Macloed’s syndrome (the late sequalae of childhood bronchiolitis).

4. Unilateral bullae.

5. Congenital lobar emphysema.

E. Pulmonary vessels :

Pulmonary embolism of a major pulmonary artery at least lobar in size.

Causes of bilateral hypertransradiant hemithoraces :

A. With over expansion of lungs :

1. Chronic obstructive emphysema :

a.Large central pulmonary arteries.

b.Peripheral arterial pruning.

c.Bullae.

2. Pulmonary Asthma.

3. Acute bronchiolitis.

Child (1st year of life).

Chest radiology 15

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*Bronchial wall thickening.

*Collapse or consolidation are common.

4. Tracheal, laryngeal or bilateral bronchial stenosis.

B. With normal or small lungs:

1. Cong heart disease oligemia e.g Right to left shunt.

2. Multiple pulmonary embolism.

3. Primary pulmonary hypertension.

4. Pulmonary artery stenosis.

5. Bilharziasis.

Increased density of a hemithorax :

A. With central mediastinum :

1. Consolidation.

2. Small or moderate pleural effusion.

3. Mesothelioma. 4. Also technical ( Rotation, scoliosis)

B. With mediastinal displacement away from dense hemithorax :

1. Large pleural effusion 2. Diaphragmatic hernia.

C. With mediastinal displacement towards dense hemithorax :

1. Collapse 2. post pneumonectomy 3. Lymphangitis carcinomatosa

4. Pulmonary agenesis and hypoplasia herniation of the other lung across

!midline.

Pneumonia with an enlarged hilum :

1. Primary pneumonia (TB, Viral, Mycoplasma, 1ry histoplasmosis IMN.),

2. 2ry pneumonias tumor

Consolidation with bulging of fissures :

1. Infection (klebsiella pn., streptococcus pn. TB)

2. Abscess (Staph, Klebsiella).

3. Bronchial carcinoma.

Causes of apical shadows :

1. Pleural caps: Unilateral or bilateral, crescent shaped, may represent old

pleural thickening, may present in 5% or population,.

2. Pancost tumor.

3. pueumothorax, bullae.

Chest radiology 16

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4. Infection (TB) + Apical fibrosis (TB, Radiation, Aspergillosis, silicosis, Histocytosis

&

Histioplamosis, sarcoidosis, scleroderma, ankylosing).

5. Pleural fluid.

6. Soft tissue (sternocliedomastoid, companion shadows, hair).

Causes of hilar enlargement :

A.Unilateral :

1. Apparent (rotation, scoliosis).

2. Normal in young women.

3. Lymph nodes as in bronchial carcinoma, lymphoma, infection as 1ry TB,

histoplasmosis, actinomycosis.

4. Pulmonary artery (post stenotic dilation, embolus, aneurysm).

5. Others (mediast, mass, peripheral pneumonia ?? I think central).

B. Bilateral :

1. Expiratory film.

2. Nodal (lymphoma, sarcoidosis, TB, carcinoma, histoplasmosis and fungi).

3. Pulmonary artery: pulmonary hypertension, congenital heart disease.

4. Extrinsic allergic alveolitis, pneumoceniosis.

EGG Shell calcification of lymph nodes :

1. Silicosis.

2. Coal miners pneumonia, amylodosis, histoplasmosis.

3. Sarcoidosis.

4. Lymphoma following radiotherapy.

Causes of small hilum:

Unilateral: normal, apparent, lobar collapse, Mcleod, unilat pul embolism and

hypoplastic pulmonary-artery.

Bilateral; cyanotic HD, central pulm embolus.

Neonatal respiratory distress :

A. Pulmonary causes :

1. With no mediastinal shift :

a. Hyaline memb. disease (ground glass appearance, larger opacities, patches of

consolidation + air bronchogram (well apparent).

Chest radiology 17

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b. Transient tachypnea (wet lung disease).

c. Meconium aspiration syndrome.

d. Pneumonia - Pulmonary hge resemble H.M.D

e. Choanal atresia.

f. Abnormal thoracic cage osteogenesis imperfecta.

2. With mediastinal shift away from abnormal side.

a. Diaphragmatic hernia.

b. Congenital. lobar emphysema.

c. Pleural effusion (rare)

3. With mediastinal shift towards the abnormal side.

a. Atelectasis (mostly misplaced endotracheal tube).

b. Agenesis.

B. Cardiac causes.

C. Cerebral causes (Hge, edema, drugs).

D. Metabolic causes (Acidosis, Hypoglycemia).

E. Abdominal causes (Massive organomegaly e.g. polycystic kidney).

Cysts : has an epithelial wall and completely closed.

Bleb : Air encysted related to pleura & completely closed → pneumothorax.

Bulla : destruction of alveoli resulting in parenchymal air encystment.

Cavity : Its wall is compressed tissues or fibrous tissue.

Pneumatocele : Thin, hair line walled air cavity.

Airway obstruction :

1. Partial hyperinflation.

2. Complete collapse.

3. Bronchocele.

4. Bronchiectasis.

5. Pneumonitis abscess.

Value of tomography :

1. To improve visualization of a lesion.

2. To localize & confirm an intrapulmonary lesion.

3. To evaluate hilum & proximal airways.

Chest radiology 18

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4. To search for a suspected lesion e.g. metastases.

5. To evaluate : mediastinum & chest wall.

Chest Wall

Comment on :

A. Sternum : 1. Developmental abnormality (depressed "pectus excavatum" sternum in cong.H.D.:

ant. ribs are vertical & post ribs are horizontal, heart is displaced to the left &

appears enlarged with straight left border, prominent lung markings (Rt paracardiac)

misdiagnosed as consolidation).

2. Erosion (adjacent mediastianal mass anteriorly, infection).

3. Tumours (chondroma, chontrosarcoma, secondaries).

4. Fractures.

B. Clavical : 1. Absence outer end : (Cleidocranial dysostosis).

2. Erosion : Outer or medial end :

- Rheumatoid arthritis.

- Hyperparathyroidism.

- Infection.

3. Tumour (aneurysmal bone cyst, Ewing).

4. Fracture.

C. Ribs: Superior or inferior unilateral or bilateral.

Rib notching (superior surface) :

A. Connective tissue disease (Rh arthritis, S.L.E, Sceleroderma).

B. Metabolic Hyperparathyroidism

C. Miscellaneous :

- Neurofibromatosis.

- Marfans’ syndrome.

- Osteogenesis impertecta.

Chest radiology 19

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- Poliomyelitis

- Old age.

Rib notching (inferior surface):

Occurs due to hypertrophy of the intevesselsor with neutumours.

- 1st and 2nd I.C. ant. & Post. costo-cervical trunk (2nd part of subclavian artery).

- 3-12 anterior inter. mammary artery 1st part of subclavian.

- 3-12 posteriorly aorta.

Causes :

-Aorta: coarctation, occlusion

-Subclavian : Takayasu disease.

-Reduced pulm flow (oligemia): Pulmonary atresia or stenosis - Fallot’s tetralogy.

-Venous : (S.V.C., I.V.C. obstruction)

-Shunts : Pulmonary or intercostal AV fistula. (Blalock operation = pulm systmic shunt)

-Others : Hyperparathyroidism, neurogenic tumour and idiopathic.

N.B. : When aorta is obstructed reversed blood flow :

- Coarctation notching of 1st and 2nd ribs : not develop because of its origin from subclavian.

- Lower ribs not affected unless : lower abd aorta is affected.

- Preductal coarctation no rib notching.

Cervical ribs : Rib anomalies (hypoplasia , bridging, bifid).

1-2%, arises from C7 with the transverse process pointing caudally.

DD: Hypoplastic 1st rib (arise from D1).

Fracture :

- Cough fracture (6-9) ribs at axillary line.

- Stress fracture 1st rib.

- Pathological fracture: senile osteoporosis, myleoma, cushing disease.

Selerosis :

A. Generalized (osteo-petrosis, metastasis, myelofibrosis).

B. Localized (Paget disease).

N.B: Looser’s zone : areas of uncalcified osteoid tissue (osteomalacia): rib deformity creates

Chest radiology 20

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a bell shaped thorax.

Expansion :

a. Localised

- Paget.

- Fibrous dysplasia.

- Haemangioma.

- Aneurysmal cyst, chondroma.

- Eosinophillic granuloma.

b. Generalized :

- Thalassaemia (expansion more marked proximally + abnormal trabeculae)

- Hurlur’s syndrome (generalized expansion sparing the proximal end).

- Rickets (widening of rib ends).

D. Thoracic spine : Comment on:

1- Alignment, disc spaces (calcification = post-traumatic, ankyloses, ochronosis,

destruction in infective process). 2-Sclerosis (single dense vertebra (ivory)=

lymphoma, paget's and metastasis. 3-Destruction (pedicle = metastases).

4- Paraspinal lines.

Straight back syndrome :

- Loss of normal thoracic kyphosis strenum parallel to spine compression of mediastinum.

- In PA view : - heart appears to be enlarged

- prominent atrial appendage

- prominent aortic knuckle.

Causes of anterior erosion of vertebral bodies :

1. Aneurysm of descending aorta.

2. Gross enlargement of left atrium.

3. Vascular tumours.

4. Neurofibromatosis.

Chest radiology 21

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Soft tissue of chest wall :

A. Skin lesion: lipoma may appear as pulmonary lesion, lateral film confirms the

diagnosis, artefacts: hair plaits, buttons...

B. Surgical etmphysema.

C. Breast, axillary folds and masses + Thyroid.

Diaphragm

Appearance ; (normal variants)

1. Scalloping (short curves of diaphragm, convex upward).

2. Muscle slips (small curved lines, concave upward).

3. Diaphragmatic hump or dromedary diaphragm (severe form may appear as double

contour in PA view N.B.: These is no diaphragmatic defect).

Eventration :

- Mainly left sided (thin, weak diaphragm).

- Left hemidiaphragm is elevated with mediastinal shift to the right, a feature rarely

seen with paralysis.

- May be associated with partial gastric volvulus.

- Reduced movement (seen under fluoroscopy) paradoxical movement or abscent.

Diaphragmatic movement :

On screen, normally the left hemidiaphragm move more than right by 3-6cm

Paradoxical movement : (Moves up with inspiration)

- Diaphragmatic paralysis.

- Subdiaphragmatic infection.

- Eventration.

Thickness of diaphragm :

- On left side between fundus gas and left lung (normal average of 8mm) normal

diaphragm 2-3 mm.

- If more than 8mm pathological (may be due to)

- Tumour of diaphragm : Lipomas - neurofibrimas, fibromas & cysts.

- Gastric tumour.

- Pleural effusion.

- Subphremic lesion.

Hernia of diaphragm :

Chest radiology 22

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- Morgagni Rt side & anterior in cardiophrenic angle.

- Hiatus hernia superimposed on cardiac shadow in PA.

- Bochdalek → Postero lat. from pleuro periteneal canal - Usually congential→lt side→

respiratory distress - Contain spleen, fat, kid, omentum or bowel.

Rupture of diaphragm :

- Trauma, surgical, may be idiopathic.

- Mainly on the left side herniation of stomach, colon strangulation.

DD : 1. Eventration (intact diaphragm)

2. Pneumothorax.

Subphrenic abscess :

- More on Rt side easy diagnosed.

- US & CT.

- Plain film :

1. Ipsilateral basal atelectasis & pleural effusion.

2. Elevated diaphragm with paradoxical or movement.

3. Gas beneath diaphragm dt. infection by gas forming org (Horizontal beam film).

4. Depression of liver edge or gastric fundus.

Causes of unilateral elevated hemidiaphragm :

A. Causes above the diaphragm :

1. Phrenic nerve palsy (bronchogenic carcinoma, surgery, trauma, idiopathic,

radiotherapy, DM, TB glands, HZ virus) ccc by:

- Smooth hemidiaphragm.

- No movement.

- Central mediastinum.

2. Pulmonary collapse.

3. Pulmonary infarction.

4. Pleural disease (old haemothorax, empyema or thoracotomy).

5. Upper motor neuron lesion hemiplegia.

B. Diaphragmatic causes of bilateral elevated hemidiaphragm :

- Eventration.

C. Causes below diaphragm :

Chest radiology 23

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- Gaseous distension of stomach or splenic flexure.

- Subphrenic abscess, hepatic abscess, pancreatitis.

DD: 1. Subpulmonary effusion.

2. Ruptured diaphragm.

Causes of bilateral elevated diaphragm :

1. Poor inspiratory effort.

2. Causes above diaphragm :

- Bilateral basal pulmonary collapse.

- Small lungs e.g. fibrosing alveolitis.

3. Causes below diaphragm :

a. Ascitis.

b. Pregnancy.

c. Obesity.

d. HSM.

e. Iatraobdominal mass.

f. Subphenic abscess (bilateral).

g. Pneumoperitoneum.

Superior medistinum mass :

- Thryoid, thymus, teratodermoid, lymphangiona, L.N., aneurysm, spinal Pott’s,

neurogenic tumours, enteric cyst, pouches.

Rib diseases :

- Notching →Sup → NF, collagen, HPT.

→Inf. → coarctation, SVC obstruction, operation, NF.

- Sclerosis → Myelosclerosis, osteopetrosis, Paget, metastasis.

- Expansion → Dysplasia fibrous

Tumours ABC, haemangisms.

Blood. dis thalassemia

Nutritional Rickets.

- Destruction → MM, metastasis, lymphona.

- Fracture.

- Cervical rib & bifid.

Linear & band shadows :

1. Pulmonary infarcts

2. Plate atalectasis often post operatively.

3. Mucus filled bronchi : gloved finger branching pattern (bronchoceles).

4. Kerley's B lines.

DD : hump in PA film

appears as a shadow in Rt

cardiophrenic angle:

1. Fat pad.

2. Lipoma.

3. Pericordial cyst.

4. Morgagni hernia.

Chest radiology 24

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5. Sentinel lines (bronch. pulm aspergillosis, malignancy, benign tumors ,congenital membrane.

6. Old pleural & pulm. scars (infarction, healed TB, sarcoid).

7. Curvilinear shadows : bullae, pneumatoceles.

8. Normal fissures & vessels.

9. Bronchial wall thickening.

Chest 24

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OCCUPATIONAL LUNG DISORDERS

PNEUMOCONIOSIS

Def.: Disease due to inhalation of particular matters.

A. Organic :

1. Damage to the tracheobronchial tree:-

Occupational asthma :

-History of exposure to animal and fungal spores and in chemical industry

e.g. Byssinosis, cotton dust inhalation.

-Has the same radiological picture of asthma during attack.

2. Damage to lung parenchyma :

Extrinsic allergic alveolitis or hypersensitivity pneumonitis:

A large variety of organic dust particles & microorganisms are small

enough (1-2m, < 10m) to reach the alveoli (act as allergens) to provoke

Ag-Ab reaction within 4-6 hours after exposure. Most of allergens are

fungal spores and proteins. eg: Farmers lung, Air condition: fungal spores and drugs

Clinically :

-6 hours after exposure fever, chills, dyspnea, cough.

-No wheezes or eosinophillia.

Radiologically :

A. During acute attack :

-May be normal.

-Mainly shows ground glass appearance with loss of definition of pulmon.vessels.

-In severe cases, extensive air space filling acinar shadowing with coalescence,

picture resemble pulmonary edema.

B. Between attacks (normal) :

-In subacute phase: reticulonodular pattern (fine lines together with small nodules

(1-3 mm).

C. With repeated attacks : pulmonary fibrosis :

Characterized by coarse lines particularly in mid and upper zones, together with

ring shadows 5-8mm causing honey comb appearance which is predominant in

upper zones (DD fibrosing alveolitis).

Chest 25

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B. Inorganic :

Damage to lung parenchyma and pleura:

1. Coal worker’s pneumoconiosis :

-Disorders due to inhalation of coal dust particles.

-It exists in 2 forms:

A. Simple pneumoconiosis :

*Causes no respiratory disability.

*Multiple discrete nodular opacities (1-4mm) more condensed in upper zones

which is mainly associated with reticular pattern Reticulonodular

appearance.

B. Complicated pneumoconiosis :

*Causes respiratory disability : progressive dyspnea, Haemoptysis.

*Gives picture of progressive massive fibrosis:

a.Large irregular opacities (1-10 cm).

b.Usually bilateral, upper zonal and asymmetrical.

c. A linear strands from opacity to periphery of lung.

d. Picture of complication (emphysema, ischemic necrosis

Cavitation).

??TB- Bronchogenic carcinoma.

NB: Miners with rheumatoid disease may develop crops of nodules varying in size 1-

10 cm know as (Caplan’s nodules or syndrome).

2. Silicosis :

Due to exposure to silica particles e.g. sand blasting and pottery, ceramic industries.

Radiologically :

Very similar to cool workers pneumoconiosis which mainly differentiated by egg-

shell calcification of enlarged hilar lymph nodes.

Simple forms : As cool workers pn. with or without hilar lymphadenopathy.

Complicated: As cool workers pn.

NB: Two important diseases may occur in association with silicosis and coal workers

pn. (TB and Bronchial carcinoma).

Chest 26

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3. Asbestosis :

The asbestos fibers, when inhaled, pass to the respiratory bronchioles and acini,

where they are engulfed by Macrophages and evoke a fibrotic response. Also, they

may penetrate visceral pleura, causing pleural reaction.

A. Pulmonary changes :

-Predominantly in lower lung zones (DD silicosis upper)

-Earliest changes are seen in costophrenic angles.

-At first the vessels have indistinct margins & are associat. with fine irregular lines.

-When fibrosis progress lines become more profuse reticular network pattern.

-With more progression give honey comb pattern, which is best seen in lateral

and oblique views

-Complications : Bronchial carcinoma, which is strongly related to cigarette

smoking.

NB: Fine irregular line Reticular network honey comb.

B. Pleural changes:

1. Pleural plaques :

-They are not seen for at least 10 years following exposure.

-They usually do not calcify until a latent period of 20 years.

-They are of variable size and have a characteristic distribution on parietal pleura.

a. Adjacent to ribs more prevalent in the axillary part of midchest and tend

to spare to upper zones and costophrenic angles.

b. Over central tendon of diaphragm which produce characteristic curvilinear

opacities on diaphragmatic pleura. Best seen in oblique views.

-CT is very sensitive for early detection.

2. Malignant Mesothelioma :

-The majority of such tumor is related to asbestos exposure and it does not arise

from pleural plaques.

-Appear as (see pleural diseases) nodular pleural thickening / hemorrhagic effusion/ central

mid diaphragm dt collapse / Rib involvement may occur.

3. Benign pleural effusion + pleural thickening. (not common to occur)

Chest 27

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Disease due to inhalation of toxic gases and fumes :

(Ammonia, chlorine and oxides of nitrogen)

Leads to :

1.Bronchitis.

2.Bronchiolitis pneumonia.

3.Allergic asthma.

4.May produce pulmonary edema (due to alveolar capillary damage) in acute

stage and pulmonary fibrosis in late stage.

Chest 28

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DIFFUSE PULMONARY FIBROSIS

INTERSTITIAL LUNG FIBROSIS (I.L.F)

Causes :

1. Inorganic dusts: (Silica, Asbestos inhalation).

2. Organic dusts: (Extrinsic Allergic Alveolitis).

3. Drugs, poisons and toxic fumes.

4. Fibrosing alveolitis (Interstitial Pneumonia): Cryptogenic & Secondary lower

zone.

5. Histocystosis X.

6. Sarcoidosis.

7. Neurofibromatosis.

8. Tuberous sclerosis.

9. Adult respiratory distress syndrome.

10. Lymphangiomyomatosis.

11. Chronic pulmonary edema.

12. Collagen dis. (Rhtoid basal/ SLE/ AS upper/scleroderma/ PAN /Wegner

granuloma/Loffler’s. ).

NB: *Key (clinically, defin, ground glassreticulonodular honey combing

*5C : Cough/ cyanosis/ clubbing/ crepitation/ Cor pulmonale.

1. Fibrosing Alveolitis Or diffuse interstitial pneumonia :

-A group of disorders characterized by an inflammatory reaction in alveolar walls

with alveolar exudate and a tendency to progressive fibrosis. Eventually, there is

complete destruction of alveolar architecture.

-Hamman-Rich syndrome: Idiopathic pulmonary fibrosis & muscular cirrhosis of

the lung all are conditions all are included in the causes of such illness.

-Types :

1ry: Cryptogenic.

2ry: In association to a variety of systemic conditions e.g. Rh. arthritis,

S.L.E., Ank. Spond., Ulcerative colitis.

Chest 29

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Cryptogenic fibrosing alveolitis :

A clinical syndrome of unknown cause (autoimmune).

Clinically :

-Middle age patients presented with presented with dyspnoea, dry cough, clubbing

of fingers, basal crepitations.

-Lung functions studies restrictive defect.

Pathologically : (Five distinct histological entities are described)

1. Usual interstitial pneumonia (most common).

2. Desquamative interstitial pneumonia.

3. Diffuse alveolar damage with Bronchiolitis obliterans.

4. Lymphocytic interstitial pneumonia.

5. Giant cell interstitial pneumonia.

Radiological features :

1. In earliest stage :

-Lungs may look normal.

-The earliest minimal changes appear :

1. Ground glass (Haze) in bases …. more easily seen in both cardiophrenic

angles (mainly unequal with more on right) which extend upward and

outward to costophrenic angles forming:

2. Generalized ground glass haziness of lungs.

2. With progression :

The pulmonary vessels lose their normal clarity and a fine reticulo nodular

pattern develops in the lower zones.

3. With more progression :

-Give (honeycomb appearance) coarse reticular pattern (at base) and ring

shadows (5-10mm).

-Best seen in post-costophrenic angle in lateral view.

-CT is very sensitive in early detection.

Chest 30

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2. Histocystosis X :

A disease of unknown etiology, usually affects multiple organs including the lungs.

Abn. proliferation of RE cells in (Bm - lung - HSM - LN).

3 varieties :

1. Eosinophillic Granuloma (mainly affect lungs).

2. Hand-Schullar Christian disease.

3. Laterer-Siwe disease.

Eosinophillic Granuloma :

Young adults (male : female = 4.1)

Pathology :

There is histocytic infiltration of the alveolar walls leading to its fibrosis

causing disorganization of the pulmonary architecture with formation of air cysts.

Radiological features :

-Wide spread, bilateral and symmetrical.

-In earliest stage normal.

-Reticulonodular pattern diffuse nodular shadowing in mid and upper zones (1-

10mm) associated with fine lines.

-With progression give honey comb appearance.

-Spontaneous pneumothorax in 20% (dt air cysts).

-Pleural reaction and hilar lymphadenopathy (rare).

-Open lung biopsy is best method to confirm diagnosis.

III. Sarcoidosis :

Multisystemic, granulomatous disorder of unknown etiology, characterized by

presence of non caseating epithelioid cell granolumas with predilection to involve

lungs, skin, L.N., adrenal, uveal tracts, C.N.S and bone.

Incidence :

(30-50ys), more common in black races, female: male =2:1).

Diagnosis :

1. Clinical data.

2. Radiological findings.

3. Histopathology. Broncho alveolar lavage.

4. Kveim test: intradermal injection of extract of sarcoid tissue reaction = +ve.

5. Gallium 67 scanning (taken by nodes and parenchymal lesions).

Chest 31

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Radiological findings :

The radiographic abnormalities progress through 3 stages :

1. Lymphadenopathy only.

2. Lymphadenopathy + pulmonary lesions.

3. Pulmonary lesions only.

Sarcoid lymphadenopathy : has the following features :

-Nodal enlargement does not develop after parenchymal shadowing.

-Appears as bilateral symmetrical lobulated hilar enlargement not common to be

asymmetrical (rarely unilateral).

-Hilar enlargement involves both tracheo bronchial and more distal bronchopulm.

lymph nodes involvement of the later is a feature of sarcoidosis where it

causes easily visualization of inferomedial border of hilum by adjacent air

containing lung.

-Hilar adenopathy is an isolated finding in about 1/3 of cases, it is associated with

right paratracheal adenopathy in another 1/3 and with bilateral paratracheal in the

remainder 1/3.

-Even with massive adenopathy, the clinically significant compression of adjacent

air ways is extremely unusual = No compression on airway.

-In 90% of cases nodal enlargement is maximal in the first radiograph and usually

disappears within 6-12 months. It may persist in 5% of cases. Recurrence of

adenopathy is very rare.

-In 5% of cases, calcification giving a characteristic egg shell fashion.

Causes of Bilateral hilar enlargement :

1. Sarcoidosis 2. Lymphoma 3. Metastasis

4. Lymphatic leukemia 5. TB (1ry) 6.Coccidioidomycosis

7. Others (silicosis, histoplasmosis, amyloidosis).

Causes of Egg shell calcification:

1. Sarcoidosis 2. Histoplasmosis.

3. Silicosis 4. Amyloidosis.

5. Lymphoma (post. irrad). 6. SIS but not TB

Chest 32

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Sarcoid parenchymal changes :

-In 20-50% with or without nodes.

-Characteristically, they appear as nodal enlargement is subsiding (DD lymphoma).

-Mainly it is bilateral, wide spread many patterns.

1. Small nodules :

2-3mm rounded or irregular nodules, slightly well defined (miliary) and

symmetrical, bilateral mainly uniform in distribution from apex to base.

2. Reticulation :

-A network of fine lines radiating from hilae.

-Kerley’s B lines may be seen from lymphatic seedlings.

3. Reticulonodular: more common, + pleural effusion & thickening.

4. Large nodules:

Multiple bilateral 1-4cm in diameter, rounded or oval in shape, usually with ill

defined border.

5. Homogenous cloudy opacities :

-Commonly contains air bronchogram giving features of consolidation.

-May be single or multiple, range from 1 cm to a segment.

-2/3 of parenchymal shadowing clear completely and 1/3 progress to :

6. Fibrosis :

-Coarse linear shadows with evidence of volume loss+ ring shadows+honey comb.

-Condensation and contraction of the fibrous tissue produces:-

1.Distortion of pulmonary architecture.

2.Elevation of hilae i.e displacement of landmarks.

X-ray staging :

0 normal

1 bilat hilar LN

2 adenopathy + pulm infiltrate

3. pulm infiltrate alone.

NB: LN + fibrosis (widespread)

Chest 33

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Complications of massive fibrosis :

-Bullae formation.

-Cor pulmonale.

-Bronchiectasis.

-pueumothorax.

IV-Tuberous Sclerosis and Lymphangiomyomatosis:

In both diseases, there is smooth muscle proliferation in bronchi, lung, vessels, ‘

lymphatics, lymph nodes and alveolar wall.

a. More common in females.

b. Mainly in lower lobe.

c. Pleural effusion (chylous) characteristic for lymphangiomata.

V. Neurofibromatosis :

The same as in Histocystosis X.

Collagen vascular diseases :

1. S.L.E.

Characterized by widespread inflammatory changes in CT, B1vs and serosal surface.

Radiological features :

1. Pleural effusion - Mostly bilateral, small, associated with pleuritic pain.

2. Segmental basal collapse : Thick horizontal band shadows at lung bases,

which occurs due to restricted diaphragmatic movement by pleurisy.

3. Pulmonary consolidation either due to (2ry infection or lupus pneumonitis).

4. Pulmonary edema : secondary to heart failure.

5. Diffuse interstitial shadowing : as in fibrosing alveolitis (rare).

6. Diminished diaphragmatic excursion: may be due to myopathy of the

diaphragmatic muscles.

Chest 34

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II. Rheumatoid Disease :

Radiographic features of intrathoracic manifestation of Rh. disease:

1. Pleural effusion: (unilateral or bilateral).

2. Necrobiotic nodules: Vary in size (few mm to few cm) single or multiple.

3. Caplan’s syndrome : In patient with rh. exposed to silica.

Identical nodules, characteristically appear rapidly in crops which contain silica

dust on histological examination.(crops of nodules = Caplan nodulo)

4. Fibrosing Alveolitis :

Appears as basal reticulonodular shadowing which may progress into honey

comb lung with loss of lung volume end stage lung.

5. Pulmonary hypertension and cor pulmonale (rare) = complication of fibrosis

III. Systemic Sclerosis (scleroderma):

-Picture of fibrosing Alveolitis (ground glass appearance/ fine reticulonodular/ honey

comb

appearance).

-Air oesophagogram may be evident in lateral film due to absence or diminished

peristalsis.

-Basal patchy consolidation due to aspiration pneumonia.

-High incidence of bronchogenic carcinoma.

IV. AnkvlS:

-Unilateral or bilateral.

-Upper lobar fibrosis with upward retraction of hilae + bullae formation.

-Apical pleural thickening.

*Causes of upper lobe fibrosis:

1. TB 5. Eosinophillic granuloma.

2. Post irradiation. 6. Sarcoidosis.

3. Histoplasmosis. 7. Ankylosing spondylitis.

4. Aspergillosis. 8. Progressive massive fibrosis.

*Causes of lower lobe fibrosis:

1. Asbestosis

2. Cryptogenic

3. Rheumatoid.

Chest 35

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V. Polyarteritis Nodosa :

-Vasculitis of medium sized arteries.

-Kidneys most commonly affected.

Radiologically :

-Transient areas of consolidation which may appear rapidly then disappear

(Loeffler’s syndrome).

- Accentuation of vascular lung markings.

- Large nodules (few cm) may cavitate.

VI. Wegener’s Granulomatosis :

-More common in females.

-Vasculitis affecting mainly small arteries and associated with segmental ‘

glomerulonephritis in 85% necrotising granulomas affecting lung. Vasculitis

“necrotising”→ skin-face, lung, kid.

Radiologically :

-Single or multiple well defined pulmonary masses varying in size from few mm

to few cm which frequently cavitate.

-Air space shadowing, may occur mainly due to pulmonary hge.

-Pleural effusion.

-Hilar and mediastinal lymphadenopathy.

VII. Pulmonary eosinphilia (Eosinophillic Pneumonia): (??Loeffler’s $.)

Eosinophillic pulmonary infiltrate + increased eosinophills in peripheral blood.

Causes :

-Bilhariziasis, ascaris, arkylostoma.

-Fungi: (Aspergillus fumigatus).

-Drugs : sulfonamides.

-Unknown : Cryptogenic pulm eosinophillia.

-Polyarteritis Nodosa.

Radiologically :

A. Loeffler’s syndrome : diagnostic vertical (short & thick) band // to chest wall

separated from pleura :

-Transient pulmonary eosinophillia which produces, ill defined non segmental

areas of consolidations in periphery of lungs.

-These changes are characteristically short lived (few days) and self limited.

Chest 36

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B. Chronic pulmonary eosinophillia :

-The same radiological picture of Loeffler’s syndrome but much more persistent.

-Classically occur in atopic middle aged females.

VIII. Pulmonary Hemorrhage & Haemosiderosis :

Multifocal bleeding at acinar level distal to terminal bronchioles with exclusion

of bleeding states as leukemia and anticoagulant.

Clinical Picture:

Haemoptysis and anemia :

Causes of Pulmonary Haemosiderosis :

1. Idiopathic : Children.

Repeated episodes of hge and the lung return to normal between attacks.

2. Associated with renal disease :

Good pasture syndrome = Antiglomerular basement membrane antibody.

3. Drugs : Penicillamine.

4. Part of widespread Vasculitis e.g. Wegener’s granuloma.

5. Miscellaneous: As in heart disease (M.S). Pulmn V. congestion.

Radiological features :

1. Of Pulmonary hge :

a. Fleeting, migrating opacities with ill defined margins like pulmonary edema ± ill

defined nodules (6mm) may be seen.

b. Airbronchogram.

c. Repeated attacks fibrosis.

NB: In severe cases, both lungs can be almost totally opacified but may be normal in

acute attack.

2. Of Haemosiderosis:

-may be normal.

- ill defined micronodular opacities (miliary) with air bronchogram.

NB: Pulmonary hge : Acinar shadow

Haemosiderosis: Miliary

Chest 37

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DISEASES OF THE PLEURA

I. Pleural fluid (effusion): types and causes :

a. Transudate :

-Clear, thin and watery fluid.

-Protein < 3gm/dl.

-caused by :

1. Cardiac failure.

2. Hypoproteinaemia (nephrotic$., hepatic C., Anemia).

3. Meig’s $.

b. Exudate :

-Cloudy amber yellow thick and sticky fluid.

-Protein > 3 gm/dl.

-Caused by :

1. Bacterial pneumonia, pulmonary TB.

2. Pulmonary malignancy (1ry or metastatic).

3. Pulmonary infarction.

4. Subphrenic infection.

5. Pancreatitis.

c. Haemothorax:

-Caused by :

1. Frank blood in pl. sac (trauma, blood dis.)

2. Blood stained effusion (pulm, infarction, bronchial carcinoma).

d. Chylothoras :

-Milky fluid high in fatty acids and neutral fat.

-Caused by obstruction or destruction of the thoracic lymphatics. The

commonest cause is :

1. Chest-trauma.

2. Filariasis, lymphoma.

3. Malignant invasion.

Radiological appearance :

A. Free effusion (in the absence of pleural adhesions).

1. Small effusion:

-< 100 cc; can not be detected by PA and lateral films but detected by decubitus

view, U/S and CT.

-100-200 cc: Can fill the posterior costophrenic recess and appear in lateral film,

Chest 38

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while not detected in PA view.

-> 200 cc: Effusion can be detected in PA view blunting of costophrenic angle.

2. Moderate effusion :

-A homogenous opacity in the lower lung zone, devoid of all lung markings,

spreading upwards, obliterating the costophrenic recess and obscuring the

diaphragmatic shadow, with well defined concave upper edge, rising laterally

more than medially (rising to the axilla).

-Tracking of the fluid in the pulmonary fissures (best seen in the lateral views).

3. Massive effusion :

-Complete or partial radio opacity of the hemithorax.

-Retraction of the underlying lung toward the hilum.

-Shift of the mediastinum toward the opposite side.

NB: Massive effusion + lack of mediastinal shift, suggesting underlying lung collapse

mostly due to bronchial carcinoma.

Atypical distribution of pleural fluid:

1. Lamellar effusion :

-Common in children and patient with heart dis.

-A shallow collection between the chest wall and lung surface, which sometimes

spares the costophrenic recess.

2. Sub-pulmonary effusion:

-An effusion accumulate between the diaphragm and under surface of the lung

false impression of elevated hemi-diaphragm.

-± Blunted costophrenic recess or tracking of fluid into fissures.

-With change in posture, in decubitus and supine films, the fluid will move in free

pleural space (diagnostic).

-On the left side increased distance between gastric air bubble and lung base.

-On the right side, a large effusion may collect in the azygo-esophageal recess and

mimic a retro-cardiac mass.

B. Loculated or Encysted effusion :

It is due to partial obliteration of the pleural space between visceral and parietal

pleura due to pleural disease or between visceral pleural at lung fissures.

Radiological appearance :

A. Costal encysted pleural effusion :

-Site : Along the chest wall (usually posterior and laterally).

Chest 39

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-R.A: Their radiological appearance depends on whether they are viewed en face,

in profile or obliquely.

-Best determined by fluoroscopy:

*Profile: well circumscribed, biconvex opacity with the peripheral border

adjacent to the chest wall and the inner border is convex and well defined.

*En-face: Radio-opacity of relatively low density.

*If air fluid level is seen it will be either due to therapeutic aspiration, or

development of bronchopleural fistula.

B. Interlobar encysted pleural effusion :

Common to occur in patients with heart failure.

1. Encysted effusion within horizontal fissure :

-Appears as lenticular; oval or rounded shadow with well demarcated edge. In

both frontal and lateral views.

-The remaining part of the fissure to be thickened due to extension of fluid

in the fissure.

2. Encysted effusion within the oblique fissure:

-PA view : Appears as rounded or oval shadow mainly well defined lower border

and ill defined upper margin.

-Lateral : Appears as a typical lenticular well defined shadow along fissure

(diagnostic).

* Interlobar effusion disappears rapidly after ttt, and may recur in subsequent episodes

of heart failure so known as pseudo or vanishing tumors, phantom tumor

Encysted effusion Middle lobe consolidation

* lenticular shape with extension into

the fissure in lateral film.

* Obliteration of right cardiac border is

not common.

* Air bronchogram.

* distorted bronchovasc. markings.

* compensatory emphysema.

* Obscuration of right cardiac order is

common.

DD. of encysted effusion :

-Extrapleural opacity from costal type.

-Parenchymal lung dis from interlobar type.

-mediastinal mass from mediastinal type.

-Free effusion DD by gravitational method.

Chest 40

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* Subpulmn encysted effusion : same as free effusion but the fluid doesn’t move into

pleural space with changing posture.

* Encysted mediastinal pleural effusion : mimic a mediastinal mass, diagnosis by

CT.

Effusion :

Free/ atypically ( lamellar, / subpulmonary).

Encysted (costal encysted, interlobar, mediastinal, subpulmonary

Chest 41

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II. PNEUMOTHORAX

Definition : Air within the pleural cavity due to defect in parietal or visceral pleura.

Etiology :

1. Spontaneous pneumothorax :

-Is the commonest type.

-In young adults cong. pleural bleb (usually in lung apex).

-Children staph. pneumonia.

-Old age Emphysema or chronic bronchitis.

-Other causes :

*Rupture of subpleural TB focus.

*Rupture of subpleural cyst in bronchial carcinoma or rupture of cavitating

metastasis.

*Conditions associated with interstitial pulmonary fibrosis, cystic fibrosis

Sarcoidosis.

2. Traumatic pneumothorax :

-Chest trauma due to : penetrating wound, closed chest trauma, fracture rib.

-Pleural or lung biopsy.

-Bronchoscopy and oesophagoscopy.

-C.V.P catheters introduction.

Radiological appearance :

A. A small pneumothorax :

-In the erect position, small pneumothorax collects at the apex and appears as a

small radiolucency in the pleural space which is devoid of lung markings. The

apex of lung retracts towards the hilum. The sharp white line of visceral pleura

will be visible.

-Expiratory films diagnostic, since on full expiration, the lung volume is at its

smallest while volume of pleural air is unchanged.

B. Large pneumothorax :

-A large radiolucency, which is devoid of lung markings.

-Lung retraction.

-Mediastinal shift toward the normal side which increase with expiration.

Chest 42

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C. Tension pneumothorax (valvular type):

-Mechanism : Air moves in but not out during respiration.

-N.B.:

*Open pneumothorax: air moves freely during respiration.

*Closed pneumothorax: No movement of air occurs.

-Radiological appearance :

*The ipsilateral lung may be squashed against the mediastinum.

*Depressed ipsilateral diaphragm.

*Mediastinal shift, especially during inspiration.

-D.D.:

*From large pneumothorax with mediastinal shift on fluoroscopy more

mediastinal shift to contralateral side in inspiration with tension

pneumothorax (?? encystment,, adhesion, thickening,, fluid collection,

collapse/consolidation) .

Complications of pneumothorax :

1. Encystment pneumothorax: due to pleural adhesion.

R.A.: Ovoid, radiolucency adjacent to the chest wall.

D.D.: Subpleural cyst and bulla.

2. Pleural adhesion:

R.A:. Appears as a line shadow between the two pleural layers preventing

relaxation of the underlying lung.

Rupture of this adhesion may produce hydropneumothorax.

3. Lobar collapse or consolidation:

4. Pleural fluid collection :

-Small amount fluid level at costophrenic angle.

-Large amount hydropneumothorax “ horizontal air fluid level”.

5. Pleural thickening :

-In chronic cases, thickening of visceral or parietal pleura may occur.

-Thickening of the visceral pleura may prevent re-expansion of the lung

which needs decortication.

* Cardiac Tamponade

NB:

1. open air in pleura communicate with atmosphere.

2. closedeg: ruptured bleb(So not open). increase pleural pr. but still -ve

3. Tension valve like tear air in not out !! increased pleural pr.

Chest 43

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III. PLEURAL THICKENING

Causes :

1. Pleurisy : primary, secondary to lung infection or infarction.

2. Previous low grade TB infection apical.

3. End result of empyema, haemothorax.

4. Following radiotherapy of the chest.

5. After asbestosis exposure diffuse pleural plaques.

6. Old age.

7. Malignancy

Common sites :

1. End of pleural fissures.

2. Apices of the lung.

3. Whole pleura (diffuse pleural thickening).

Radiological appearance :

Bilateral apical thickening or symmetrical :

- Elderly patients.

- Uncertain etiology.

- Not due to TB.

- Ischaemia is a probable factor.

Unilateral apical thickening or asymmetrical :

- Pancost tumor.

- TB + Ank. spondylitis.

- Always of pathological significance.

Extensive pleural thickening :

- (unilateral or bilateral) Fibrothorax.

- Common with asbestosis.

Diffuse pleural thickening :

- Usually, the end result of previous thoracotomy, empyema, or haemothorax.

- This may cause reduced ventilation of the surrounding lung decrease in the

volume of that hemithorax.

- Decortication of the visceral pleura is needed.

Chest 44

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IV. PLEURAL CALCIFICATION

Causes : The same as pleural thickening :

Radiological appearance :

-Continuous sheet or discrete plaques - usually producing dense, coarse, irregular

shadows.

-When viewed tangentially - characteristically parallel to the chest wall.

-When viewed en face bizarre form of calcification, which may cast an ill

defined shadow mimic to pulmonary infiltrate.

V. BRONCHOPlEURAL FISTULA

Communication between the air way and pleural space :

Causes :

1. Complication of pneumonectomy.

2. Rupture of lung abscess or empyema.

3. Carcinoma of nearby bronchus.

4. Penetrating chest trauma.

Radiological appearance :

Plain :

Picture similar to hydro or pyopneumothorax (if persists or enlarges after surgery,

BP fistula should be considered).

Contrast study :

-Injection of lipidol or hydrast into pleural space (sinography or passes into the

bronchial tree.

-Injection into bronchial tree passes to pleural space.

Chest 45

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VI. PLEURAL TUMOURS

-Benign (Lipoma) and (fibroma) = Benign mesothelioma.

-Malignant Primary = Malignant mesothelioma.

-Malignant secondary = commonest sites is breast, bronchogenic...

Pleural fibroma :

Usually associated with hypertrophic osteoarthropathy joint pain and clubbing.

Radiological appearance :

Well defined lobulated mass :

- Site : Costal, diaphragmatic, mediastinal or at pleural fissures.

- Size : Small or occupy most of hemithorax.

Subpleural lipoma :

- Well defined rounded masses.

- May change their shape with respiration (fluoroscopy).

Malignant mesothelioma :

Usually due to prolonged exposure to asbestdust.

Radiological Appearance :

- Nodular pleural thickening around all or part of a lung.

- Hemorrhagic pleural effusion may be present, which may obscure ! mass.

- Mediastinum is mainly central despite of the presence of a large effusion due to

underlying collapse of the lung by:

*Ventilation restriction by the tumor.

*Bronchial ??/ stasis by tumor compression.

- Rib involvement may occur not common as in metastasis.

- Other asbestosis changes (pleural thickening, pl. calcification)

- CT is the best method for assessing the extent of malignant mesothelioma.

- Percutaneous or U/S needle biopsy is diagnostic.

Chest 46

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CHRONIC OBSTRUCTIVE

AIRWAY DISEASE

I-Bronchial asthma :

Definition : Widespread narrowing of the bronchi, which is paroxysmal and

reversible.

Pathogenesis : Hyper-reactivity of the larger air ways to a variety of stimuli

narrowing of bronchi, wheezing, dyspnea.

Types :

1. Extrinsic or atopic asthma : Associated with history of allergy eg.

Aspergillosis (↑ IgE).

2. Intrinsic or non atopic: Precipitated by a variety of factors as exercise,

infections.

Radiological appearance :

*In between acute attacks: Normal chest.

*During acute attacks :

1. Evidences of hyper inflation “see later”.

2. Prominent bronchovascular markings.

3. Hilar vessels enlargement (enlarged central pulmonary artery) with

normal pulmonary vessels distal to hilae, mainly due to reversible

pulmonary hypertension.

*Radiographic picture of associated conditions:

1. Recurrent infections especially in children, causing bronchial wall thickening

“peri-bronchial cuffing”. Appear *End-on ring shadows.

*Profile tubular tram-line shadows.

2. Flitting, patchy infiltrates of Aspergillosis.

*Radiographic picture of complications :

1. Manifestations of lower respiratory tract infection.

2. Lobar atalectasis: dt: obstruction of a lobar bronchus by plugs of sticky mucus

or mycelia of Aspergillus. Most common in Rt middle lobe.

3. Pneumothorax and pneumomediastinum: due to rupture of the alveoli by high

expiratory pressure.

Chest 47

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II-Chronic bronchitis :

Definition : Production of cough on most of day, during at least 3 consecutive

months for more than 2 years, without apparent cause.

(> in smokers, ♂, Pollution)

Pathology :Hypertrophy of mucous secreting glands interference with mucociliary

function dt: viscous sputum production with plugging of distal air ways.

Radiographic picture :

- 50% of patients normal chest.

- Signs of over inflation.

- An appearance which is characteristic for chronic bronchitis: Dirty chest:-

- Accentuated bronchovascular marking with small, ill defined opacities which

may represent small focal areas of atalectasis, fibrosis, perivascular and peri-

bronchial edema. DD: IPF & bronchiectasis

- Bronchial wall thickening “As before”. Peribronchial cuffing : rounded, tram like.

*Picture of complications :

- Emphysema.

- Cor-pulmonale.

- T.B.

- Bronchogenic carcinoma.

- Pneumothorax.

Bronchography :

- Unnecessary but pathogneumonic for diagnosis of chronic bronchitis.

- Shows, evidence of hypertrophy of mucous secreting glands in larger air ways.

- Irregular wall of proximal bronchi.

- Abrupt termination of bronchial division after 5-8 generations = Prune tree.

Emphysema : Definition : Enlargement of airways beyond (distal) to the terminal bronchioles with

dilation and destruction of their walls.

NB:- *Trachea, bronchi & bronchioles are strictly conducting airways.

*Resp. bronchioles, alveolar ducts & alveolar sacs-conducting & respiratory structures.

*Alveoli are purely respiratory function.

*Bulla : emphysematous space with diameter > 1 cm in the distended state & its walls are

made up of compressed surrounding lung or pleura.

Chest 48

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Secondary pulmonary lobule : Areas supplied by 3-5 terminal conducting

bronchioles, separated by septa = 3-5 acini

Respiratory acinus = lung distal to a terminal bronchiole.

Composed of all respiratory structures distal to a terminal bronchiole = primary

lobule (Respiratory bronchiole, alveolar duct and sac.)

Types of emphysema :

A. Air trapping present at the respiratory bronchiole “symptomatic”:

1.Panacinar : Panlobular :

- Non selective process, characterized by destruction of all the lung distal to the

terminal bronchiole. ??Alpha-1-anti-trypsin deficiency.

- It may be localized or generalized.

2. Obstructive emphysema : misnomer : obstructive hyperinflation (bec. distal airway

is not necessarily destroyed).

- It occurs, when a larger bronchus is partially occluded by an intra-luminal mass

ball valve effect of this mass, in such a way that air enters the lung on

inspiration but is trapped on expiration.(FB or peribronchial tumor).

3. Para-cicatricial emphysema:

-Distention & destruction of terminal air spaces adjacent to fibrotic lesions eg TB.

4. Congenital lobar emphysema :

- Refers to an overinflated lobe which compresses adjacent normal lung producing

respiratory distress mainly in the neonatal period.

- Causes :

1. Deficiency of a bronchial wall cartilage.

2. Obstruction to a lobar bronchus by an extrinsic mass or anomalous vessels.

3. Alveolar abnormality

*Polyalveolar lobe increased number of alveoli in a lobe

*Rigid alveoli with surrounding stroma.

5. Unilateral or lobar emphysema (Macleod’s syndrome):

- It is probably the result of a childhood viral infection causing bronchiolitis and

obliteration of the small airways, the involved distal air ways are ventilated by

collateral air drift air trapping of pan-acinar type.( hypertransradiant hemithorax

dt decrease perfusion.)

Causes of unilateral lung transradiancy :

Chest 49

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1. Technical radiographic factors.

2. Thoracic cage abnormalities.

3. Pulmonary embolism.

4. Compensatory or obstructive emphysema.

B. No air trapping “asymptomatic”:

1. Centri-acinar : centrilobular.

- Selective process, characterized by destruction and dilatation of respiratory

bronchioles, where the alveolar ducts, sacs and alveoli are spared.

- It is frequently found in chronic bronchitis.

2. Focal dust emphysema :

- Similar to centri-acinar emphysema, but in association with cool dust exposure.

3. Para-septal emphysema:

- Usually involves the periphery of the secondary lobules at the lung periphery

occasionally causes bullae formation.

4. Senile emphysema :

- Dilatation of the alveolar ducts due to the aging process.

- Non significant.

5. Compensatory emphysema (hyperinflation):

- Hyperinflation of the unaffected or remaining lung due to collapse of a part or all

of the lung.

Causes of lobar emphysema :

I-Bronchial obstruction:

- Abnormal bronchial wall (cartilage deficiency, bronchial stenosis)}Panacinar

- Extensive bronchial compression.}Panacinar

1.Vascular anomalies vascular ring or sling.

2.Mediastinal mass e.g. bronchogenic cyst.

- Intra-bronchial obstruction: (All obstructive except 4 is paracicatricial)

1. Mucous plugs. 3. Tumors.

2. F.B. “Peanut”. 4. Endo-bronchial TB.

II. Parenchymal abnormalities: (congenital)

1. Polyalveolar lobe.

2. Rigid alveoli.

NB: *Type I resp failure: diffusion defect (hypoxic, normo or hypocapnic eg pul. edema, pure

Chest 50

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emphysema, ARDS. (Oxygen as much as you want)

*Type II : ventilation defect (hypoxic, hypercapneic) GOAD, restrictive lung dis (differentiated

by FEV1). ( Care with oxygen therapy)

Radiological appearance :

The classical radiographic appearance of advanced emphysema consists of a triad

of findings (overinflation, vascular damage, bullae).

I. Panacinar :

1. Over inflation : manifested by low flat diaphragm

- Normally at end of deep inspiration the diaphragm is at the level of 6th-7th

anterior rib in frontal view, and 10-11 posterior rib. Best seen in lateral view.

- In emphysema, there is low position of the diaphragm below these levels at end

of inspiration, associated with flattening of the diaphragmatic dome.

- The low flat diaphragm results in an apparently small heart, “elongated” and

decreased cardio-thoracic ratio < 40%, & transverse ribs.

- Limited diaphragmatic movement with emphysema by fluoroscopy and

inspiratory, expiratory films, Where diaphragmatic excursion is about 5-10cm,

in emphysema it is < 3cm.

- Enlargement of retrosternal translucent zone on the lateral radiograph measured

from the back of the sternum to the anterior aspect of lower ascending aorta ..

should be 4cm or greater to be considered abnormal.

- Increased AP diameter of chest (barrel chest) due to bowing of the sternum

and increase thoracic kyphosis.

2. Vascular changes :

A. In widespread, generalized emphysema:

- The midfield and peripheral pulmonary vessels are attenuated in both size and

number, where the normal smooth gradation in size of vessels from the hilum

outwards is lost.

- The hilar vessels being larger than normal with abrupt tapering.

B. Localized emphysema :

Chest 51

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There is uneven distribution of pulmonary vessels where :

- Vessels of occasionally increased caliber are present in unaffected areas of lung

... termed marker vessels which is used as a touchstone for normality and allow

one to identify emphysematous area.

- The vessels are smaller and more deficient in the emphysematous areas.

- When, emphysema is predominantly basal (lower lobe emphysema) which is

common in panacinar type, it is mainly associated with “upper lobe blood

diversion”, as the perfusion of emphysematous lung is less than normal and the

pulmonary blood flow is diverted to less affected areas of lung.

- With development of cor pulmonale or left heart failure, the radio graphic

picture of emphysema will alter where :

a. The signs of hyperinflation may be decreased.

b. The level of diaphragm will rise, this is due to pulmonary edema

decrease of the hung volume.

c. The heart may appear normal or enlarged.

DD of upper lobe blood diversion :

1. High pulmonary venous pressure as in left heart failure.

2. Severe lower lobe disease.

- Emphysema.

- Fibrosing Alveolitis.

- Bronchiectasis.

- Pulmonary embolism.

3. Bullae :

Can be identified in about 1/3 of patients of emphysema, also may be seen

independently of emphysema.

Radiological appearance:

a. Rounded or oval translucency, more than > 1cm in size.

b. Smooth, curved, hair line wall (compressed lung parenchyma.)

c. Causing distortion or displacement of pulmonary vessels.

d. May be single or multiple.

e. Usually peripheral.

Giant bullae :

Chest 52

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- It occupies most of the hemithorax.

- Compression of adjacent lung.

- Displacement of fissure and depression of hemi-diaphragm.

- May cause mediastinal shift or extends across the midline or retro-sternal space.

NB:*Many bullae may be invisible on chest radiograph and can be demonstrated by :

- Expiratory films, (air trapping within the bullae).

- CT scanning.

Complications of bullae formation :

1. Infection :

- Where a fluid may partially fill it forming fluid level or completely filling it

and appears as a well-defined homogenous opacity.

- The surrounding lung shows inflammatory changes.

2. Hemorrhage : Forming fluid level.

3. Pneumothorax : Rare if rupture.

DD: of localized transradiancy :

1. Bullae.

2. Encysted pneumothorax.

- The bullae shows - Curvilinear margin, outer aspect of which makes an

acute angle with the chest wall.

- Has lung tissue peripherally.

3. Cyst.

4. Pneumatocele tomography may be needed.

5. Localized emphysema.

II. Obstructive emphysema : 1. Vascular changes as before.

2. Air trapping picture by fluoroscopy and expiratory films.

*Transradiancy of affected lobe or segment.

*Deviation of mediastinum to normal side.

*Low flat ipsilateral diaphragm with restricted movement.

3. When lobar :

*Displacement of fissures.

*Compressed lung tissue around.

III. Macloed’s syndrome :

Chest 53

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1. Plain :

-Hyperlucency of the affected lung due to attenuation of vessels within it.

-Air trapping effect of the affected lung, but no over inflation as above.

2. Bronchography :

Not usually indicated, but shows a characteristic app.:

- Main and segmental bronchi are normal.

- Irregular dilatation of peripheral bronchi till, 6th order division.

- Lack of bronchial filling distal to the 6th order division (bronchiolitis obliterans)

giving pruned tree appearance.

3. Pulmonary angio:

- Not commonly used, reveals: attenuation of pulmonary vasculature of the

affected side.

4. Isotope :

- perfusion scan shows decrease flow.

- Ventilation scan air trapping

DD. of unilateral emphysema : =Other causes of hypertransradiant hemithorax :

A. Rotation :

- Technical.

- Scoliosis :hypertansradiant hemithorax is the side to which the patient is turned.

B. Chest wall deficiency :

- Mastectomy.

- Poland’s syndrome (congenital absence of pectoral muscles).

C. Pleural :

- Contra-lateral pleural effusion with patient supine.

- Pneumothorax.

D. Parenchymal :

- Lobar collapse compensatory emphysema.

- Bronchial.

1. Obstructive emphysema. 3. Macloed’s syndrome.

2. Unilateral bollus emphysema.

- Arterial :

1. Congenital absence of one of pulm. a.

2. Pulm. A. (occlusion embolism, nearby carcinoma)

IV- Congenital Lobar Emphysema:

Chest 54

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- Variable degree of overinflation of one lobe mostly the upper & middle lobes →

show hyperlucency with few visible lung markings.

- The over expanded lobe leads to

1. Compresses remaining lung

2. Flattens or inverts ipsilateral lung

3. Mediastinal shift towards opposite side.

4. May herniate across the midline to opposite side.

DD of Cong. Lobar Emphysema:

1. Tension pneumothorax : - Entire ipsilateral lung is collapsed.

- No vascular markings within it.

2. Congenital cyst : evidence of other cysts.

3. Compensatory hyperinflation (no evidence of expiratory air trapping).

4. Obstructive hyperinflation ...... mainly due to mucous inspissation and plugging

of a bronchus which may give identical picture of C.L.E…..so bronchoscopy is

essential before surgical resection of lobe in C.I.E.

V. Emphysema with chronic bronchitis : (centriacinar/ no air trapping)

Clinically emphysema of two type (Pink Buffer, Blue Blotter)

Pink Buffer :( Pt. by major effort ventilates sufficient to maintain normal bl. Gases).

More common with pan acinar emphysema.

- Manifestation of hyperinflation.

- Peripheral vascular attenuation.

“Where we call arterial deficiency pattern of emphysema”

Blue Bloater : (Chronically retains Co2 dt poor alveolar ventilation).

More common with centri-acinar emphysema :

- Increased bronchovascular marking ... dirty chest.

- Enlarged central pulmonary arteries ....... possibly with cardiac enlargement.

(+ Cor pulmonale → edema)

- Signs of hyperinflation is not severe.

This is called ..... increased markings pattern of emphysema.

- Patient with chronic bronchitis shows features between these two extremes

(panacinar + centri-lobular).

Complications of emphysema :

Chest 55

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1. Pneumonia : produces, ill defined, patchy, nodular shadowing.

2. Pulmonary edema: of left heart failure with upper lobar in distribution.

3. High incidence of bronchial carcinoma.

4. Cor-pulmonal.

5. Pneumothorax.

6. Respiratory failure.

DD of Emphysema:

1. Asthma: during acute attacks.

2. Primary pulmonary arterial hypertension .... there is no evidence of hyper

inflation.

Chest 56

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LARGE AIR WAY OBSTRUCTION

Causes of bronchial obstruction:

A. In the lumen:

1. Foreign body.

- Air trapping > atalectasis.

- Lower lobe is most frequently affected.

2. Mucus plug.

- Post operative, asthma.

3. Misplaced endo-tracheal tube.

4. Broncho -pulmonary aspergillosis.

B. In the wall (mural):

1. Carcinoma of bronchus Tapered narrowing ± irregularity.

2. Bronchial adenoma Smooth, rounded filling defect.

3. Inflammatory stricture (TB).

4. Bronchial atresia.

5. Sarcoid granuloma.

6. Fracture bronchus.

C. Outside the wall:

1. Adenopathy.

2. Mediastinal tumor.

3. Enlarged left atrium.

4. Aortic aneurysm, vascular ring.

5. Cong., vascular anomalies.

Manifestations of partial or complete major air way obstruction:

1. Collapse or atalectasis. (if complete ob.)

2. Obstructive hyperinflation if partial ob (valve).

3. Obstructive pneumonitis abscess.

4. Bronchocele.

5. Bronchiectasis.

Chest 57

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COLLAPSE (ATELECTASIS)

Collapse means partial or complete loss of volume of a lung.

Mechanisms of collapse (types):

1. Relaxation or passive collapse.

Air or fluid in the pleural sac passively causes the lung to retract towards its

hilum.

2. Cicatrization collapse :

The lung can not normally expand (decrease lung compliance) decrease it

volume. Occur in pulmonary fibrosis.

3. Adhesive collapse :

Normally the surface tension of the alveoli is decreased by surfactant

disturbance of such mechanism leads to alveolar collapse with patent major

airway. e.g. respiratory distress syndrome in premature.

4. Resorption collapse (obstructive): (causes : outside - inside - lumen)

Acute bronchial obstruction leads to absorption of gases within the alveoli by the

blood of pulmonary capillaries leads to alveolar collapse no air bronchogram.

Radiological appearance of collapse: (direct - indirect).

A. Direct signs (Lobar signs) of collapse :

- Displacement of the interlobar fissures. The most reliable sign.

The degree of displacement depend on extent of collapse.

- Loss of aeration or increased density of the collapsed area.

The collapsed area adjacent to mediastinum or the diaphragm will obscure

their defined border “silhouette sign”.

- Vascular and bronchial signs:

Crowding of vessels in the collapsed area.

Crowding of bronchi if there is air bronchogram.

B. Indirect signs (extra-labor):

Chest 58

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1. Elevation of the hemidiaphragm: especially in lower lobes collapse.

2. Mediastinal shift:

- Tracheal shift to the same side in upper lobe collapse.

- Shift of the heart to the same side in lower lobe collapse.

3. Hilar displacement:

- Elevated in upper lobe collapse.

- Depressed in lower lobe collapse.

4. Compensatory hyperinflation of the normal parts of the lung:

- In total lung collapse compensatory hyperinflation of the contralateral

lung ? explain.

5. Rib approximation.

PATTERNS OF COLLAPSE A. Entire lung collapse “complete collapse”:

Acute obstruction to one of the main bronchi lung collapse and causes

1. Opacification of the hemithorax.

2. Displacement of the mediastinum to the affected side.

3. Elevation of the diaphragm.

4. Rib approximation.

5. Compensatory hyperinflation of contralateral lung.

a. Hyperlucency with accentuation of its vascular marking.

b. Widening of rib spaces.

c. Herniation across mediastinum, mainly occur in the retrosternal space or in

azygo-ocsophageal recess posteriorly or across the midline.

B. Lobar collapse:

1. Right upper lobe collapse :

PA view : -The outer aspect of minor fissure moves upward with concavity inferior.

- Tracheal shift to the right.

- Loss of definition of shape of right border of superior mediastinum

(Silhouette sign),

Chest 59

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- Elevation of right hilum with more horizontal course.

- Compensatory hyperinflation of the lower lobes.

N.B: In marked collapse, the collapsed area comes to lie against the apex

and mediastinum simulating (apical pleural thickening, or superior

mediastinal widening.

Lateral view :

- The minor fissure and upper part of the oblique fissure move towards

each other.

- Effacement of the anterior margin of the aorta.

- Wedge like opacity with its base towards apex of the lung and its apex

towards the hilum.

2. Right middle lobe collapse:

PA view : - Lateral part of minor fissure moves downward.

- The area of opacity, mainly not seen but usually sufficient to blur the

sharp right heart border (Silhouette sign) best sign.

Lat. view :

- The minor fissure and lower half of oblique fissure move towards each

other with bowing of one of them or both.

- Increased density of middle lobe.

- In severe collapse band shadow extends downward and forward from

hilum.

Lordotic view:

- The collapsed middle lobe appears as triangular shadow with its apex

pointing laterally from which, the fissure line usually extend to chest

wall.

DD.: Encysted interlobar effusion of lower part of major fissure (no air bronchogram,

lat view → lenticular, no oblit. of cardiac silhouette.

3. Lingular collapse :

Mainly involved in left upper lobe collapse :

PA view : Loss of definition of the left cardiac border.

Lat. view : Ant. displacement of lower part of oblique fissure and increased opacity anterior to it.

Chest 60

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4. Collapse of the right or left lower lobe :

PA view :

- With minor volume loss no increase in radio-opacity.

- As collapse progress, there is increase in radio-opacity forming a triangular

shadow with its apex in hilar region and its base on diaphragm. On the left side it

lies behind the heart and penetrated film may be needed ... In this situation,

indirect signs are important such as:

a. Silhouette sign: on left side (obscuration of the margin of hemidiaphragm

and descending aorta). On right side : The border mainly remains sharp.

b. Hilar depression with medial shift of its inferior component.

c. Hyperinflation of the ipsilateral upper lobe.

d. Diaphragmatic and mediastinal shift.

Lateral view :

- The lower part of oblique fissure mainly bowed convex backwards & sometimes

its upper posterior aspect is depressed by compensatory hyperinflation of upper

lobe.

- With marked volume loss increased radio opacity in the posterior

costophrenic angle and loss of lucency of the lower dorsal spines.

5. Left upper lobe collapse :

PA view :

- Ill defined hazy opacity present in upper, mid and sometimes lower zones. More

dense at hilum.

- III defined border of aortic knuckle, hilum and the left cardiac border it lingula is

involved (Silhouette sign +ve.)

- Shift of trachea to the left.

- Hyperinflation of the left lower lobe.

- Elevated hilum.

Lat. view :

- Anterior displacement of the oblique fissure.

- With increased collapse, the upper lobe retracts posteriorly, forming an

elongated opacity extending from the apex, anterior to ! hilum and lined

posterior by oblique fissure.

Chest 61

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C. Multilobar collapse :

Right middle and lower lobe collapse dt to obstruction of bronchus intermedius.

PA view :

- A triangular shadow, with its apex at hilum and its base on diaphragm extending

laterally to costophrenic angle.This distinguish it from isolated lower lobe

collapse.

- Obliteration of diaphragm and right cardiac border.. DD: subpulmonary effusion

or elevated right diaphragm.

Lat view :

Radio opacity of a well defined upper border extending downward and forward

from back to front which obliterates the whole hemidiaphragm.

D. Atypical forms of collapse :

1. Rounded atalectasis or folded lung:

- A homogenous opacity, with ill defined edges, always pleural based and

associated with chronic pleural thickening DD: pulmonary mass.

- A vascular shadow may be seen to radiate from part of opacity mimicking a

comet’s tail comet sign.

- This type of collapse occurs, when pleural effusion causes fold of the adjacent

lung mainly lower lobe and the folding failed to resolve when effusions subsides

(with asbestosis).

2. Fleischner’s plate atalectasis :

- Linear densities appear in the lower lung fields soon after abdominal surgery.

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CONSOLIDATION

Definition: Means replacement of air in one or more acini by fluid or solid

material. The smallest unit of consolidation is a single acinus which

casts a shadow approximately 7mm in diameter.

Causes of consolidation:

- The most common cause is acute inflammatory exudation associate with

pneumonia.(TB, infarction, collapse), (same as causes of alveolar and acinar shadows)

- Other causes:

- Pulmonary edema.

- Hemorrhage, aspiration.

- Alveolar carcinoma, lymphoma.

Consolidation is either : patchy, segmental, or lobar

Consolidation :

- When associated with patent air way air bronchogram is seen with to change

in volume .

- When it occurs secondary to bronchial obstruction no air bronchogram seen

and there is decrease in lung volume = consolidation collapse.

Air in alveoli is displaced by:

Fluid

Pneumonia, TB, IPF, bronciectasis

Pulmn. edema

Pulmn. hge

Pulmn infection

Soft tissue

Alveolar cell carcinoma

lymphoma

Chest 63

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OBSTRUCTIVE PNEUMONITIS

Pneumonic consolidation distal to an obstructive lesion :

The presence of underlying airway obstruction with consolid. can be suspected from :

1. Segmental or lobar distribution.

2. Atalectasis : Marked volume loss, which does not occur with simple

pneumonia. Tomography and bronchoscopy can exclude br.

obstruction.

3. Drowned lung: When fluid and exudate fill the lung distal to an obstruction

appears as dense homogenous consolidation with absent air

bronchogram.

4. Slow resolution : Generally if pneumonic consolidation persists more than > 8

weeks after appropriate therapy in a patient who does not

have any systemic disease→ suspect underlying obstruction

5. Recurrence : Repeated pneumonia to same segment or lobe is highly

suggestive of obstructing bronch. lesion, or local parenchymal

abnormality as bronchiectasis.

OBSTRUCTIVE HYPERINFLATION

See emphysema

BRONCHOCELE (MUCOID IMPACTION)

Definition: Accumulation of mucus, pus or caseous materials within distended

bronchi distal to a segmental bronchus but without collapse.

Radiological features :

- Oval or finger like branding homogenous opacities along the axis of bronchial

tree usually upper lobe.

- Tomography (this low density is clearly seen)>

- Bronchography shows obstruction as sharp cut off in the contrast column.

- With increasing distension, bronchocele assumes a round shape DD from

bronchogenic cyst.

- Infection bronchiectatic changes.

DD: Arteriovenous malformation by:

*Multiplicity in AVM with presence of feeding and draining vessels.

*Absence of obstructive hyperinflation in AVM.

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BRONCHIECTASIS

Irreversible dilatation of a bronchus (persistant dilataion of ! bronchi ass. with suppurative

infla.

Etiology :

Commonly due to a severe, recurrent or persistent infection which leads to

dilation of large airways and obstruction with destructive process of smaller ones

bronchiolitis obliterans.

NB: Inflammation & destruction: large bronchi dilated (yield under pr.)

* Small obstructed (bronchiolitis obliterans).

Predisposing factors (infection) :

1. TB

2. Severe childhood pneumonia especially (pertussis, measles).

3. Those associated with bronchial obstruction.(luminal, extraluminal, intraluminal ).

4. Those associated with either inborn immunological defect or with inborn

structural abnormalities of bronchial wall e.g. Kartagner’s syndrome.

*Non infective bronchial wall damage : occurs following inhalation of toxic gases and

allergic damage of aspergillosis.

Site :

- May be localized, multifocal or generalized.

- It is commonly basal but it may be confined to upper zone e.g. TB.

CP: See internal medicine (Chest: cough,expectoration, positional- toxemia,clubbing, complict)

Types of bronchiectasis : (features of bronchography)

1. Cylindrical bronchiectasis : = tubular.

- Bronchial dilation is generally mild with more or less parallel walls, “squared

of” ends and some preservation of the side branches.

- DD :

a. Chronic bronchitis mild and more widespread.

b. Collapsed lobe mechanical dilation of collapsed lobe.

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2. Varicose and cystic or saccular type :

- Much more dilatation and irregularity with a beaded or saccular outline to

airway which end in a bulbous fashion.

- The side branches are permanently occluded and only a handful of bronchial

generations distal to the lobar bronchi remain patent.

3. Fusiform bronchiectasis :

- Varicose bronchiectasis with preserved side branches.

- This appearance, typically at segmental or subsegmental level is highly

suggestive of allergic aspergillosis.

Radiological features :

1. It may be normal in 7%

2. Peribronchial thickening and retained secretions.

3. Cystic spaces = air fluid levels.

4. Crowded vessels i.e loss of volume.

5. Coarse honeycomb pattern in very severe disease.

Bronchography : as types of bronchiectasis.

CT : Can identify the degree of bronchiectatic changes and underlying disease

(before surgery.)

Chest 66

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PULMONARY NEOPLASM

Benign : Intrabronchial tumors (adenoma), pulmonary tumors (hamartoma, angioma)

Malignant : Bronchial, carcinoma., others, metastasis, malig, lymphoma, (carcinoid,

cylindroma).

BRONCHIAL OR BRONCHOGENIC CARCINOMA

Incidence: Male:female 5:1, Age : peak at 6th decade.

Predisposing factors : Cigarette smoking and asbestosis (pneumocon).

Pathological types :

1. Squamous cell carcinoma 50%. (central, large cavitates).

2. Adenocarcinoma, including alveolar c. carc. 20% (bronchioloalveolar cell/

periph., pancost.

3. Undifferentiated carcinoma.

- Small cells (Oat cell type) 20%. (APUD, never cavitates, small , massive hilar LN)

- Large cell type 10%. ( periph. or central.)

Types :

- Central: tumor arising at bronchus - early complain 66%

- Peripheral: tumor arise from lung tissue late complain 33%

Diagnosis of bronchogenic carcinoma depends on :

1. Clinical picture.

2. Radiological pictures.

a. Plain.

b. Tomography : Better definition of lesion but does not differentiate benign

from malignant.

c. Computed tomography (the best) + MRI.

d. Biopsy (U/S, CT guided, or at bronchoscopy).

NB: Central : WHO I: sq-cell car central, large, cavitates.

WHO II: oat small all anaplastic central, never cavitates, small, hilaer LN.

Peripheral: WHO III: Adenocarcinoma pancost, apical, peripheral, horner.

WHO IV: Large cell carcinoma.

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Radiological features :

A. Peripheral tumors: A mass in lung having the following features :

1. Shape : Mainly spherical, may be oval or dumbbell shaped.

2. Border (edge):

- Lobulated, notched (umblicated) or irregular ill-defined.

- Corona radiata: Numerous fine strands may be seen radiating into lung from

mass with more transradiant lung parenchyma than normal between these

strands which is highly suggestive for carcinoma.

3. Size : variability is unusual to identify a nodule, until it is 1cm in size or more.

4. Calcification : Lack of calcification is the basis and when it is present it is mainly

due to engulfment of the tumor to pre-existing calcified granulomata (TB,

fungal)

5. Cavitation : (better seen by CT or tomography).

- The peripheral lung mass may cavitate, revealing central air lucency.

- An air fluid level (when communicates with air way).

*The cavity : a. Frequently eccentric.

b. Thick, irregular wall, rarely smooth.

c. Tumor nodules may be visible, which may break off and lie within

the cavity simulating to a mycetoma.

*NB:-Squamous cell carcinoma cavitates more frequently than the other types while

Oat cell carcinoma never cavitates. -DD : from other cavitary lung lesions.

6. Mass effect:

- Bronchocele, due to obstruction to the segmental or subsegmental bronchus.

- Appear as peripheral tubular density which may branch &occur distal to the

mass.

7. A peripheral line shadow (Tail):

- May be seen between a peripherally located mass lesion and pleura.

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- This phenomenon can occur in both benign and malignant lesion.

- It is mainly due to plate like atalectasis, secondary to bronchial obstruction or

septal edema due to lymphatic obstruction.

B. Central tumors : Identified by (mass, signs of air way obstruction).

1. Signs of central carcinoma :

1. Unilateral hilar enlargement which is either due to:

a. Central bronchial mass.

b. Enlargement of lymph nodes (hilar).

Differentiated by shape & extent of lesion.

* The more lobular ! shape, the more ! wide spread more suggestive for

adenopathy.

* Increased density of hilum at one side without significant enlargement may

occur to super imposition of the mass on hilum.

2. Signs of air-way obstruction (+ SVC)

- Encroachment of ! tumor on bronchial lumen causes irregular narrowing or even

complete obstruction of a major bronchus leading to :

a. Atalectasis (+ its signs).

b. Consolidation due to :

- Inability to evacuate secretion.

- 2ry infection (pneumonia).

c. Consolidation-collapse.

NB: Features suggestive of pneumonia secondary to a bronchial

carcinoma :

1. Pneumonia confined to one lobe with loss of volume.

- (No) air bronchogram mainly absent.

- Bronchoscopy should be done.

2. An associated hilar mass is rare to occur with simple pneumonia.

3. Pneumonia that remains confined to one segment for more than 2 weeks

without clearing or spreading into other segments as in simple pneumonia.

4. Persistence of localized pneumonia on appropriate antibiotic therapy for

more than 8 weeks.

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C. Spread of tumor :

1. Hilar and mediastinal lymph node metastasis :

- May be present at the time of initial diagnosis particularly with adenocarcinoma

and Oat cell carcinoma.

- Central adenopathy may be difficult to be recognized by plain film and can be

only recognized by CT or tomography.

- CT is the most sensitive method for detecting mediastinal adenopathy.

- The size of ! L.N. detected is of great importance in suggestion of metastasis.

* < 1 cm in diameter much suggestive to normal.

* 1-2 cm in diameter considered abnormal but not necessarily neoplastic.

* > 2cm more suggestive of metastatic neoplasm.

2. Mediastinal invasion :

- Can not be evident on plain film, unless phrenic nerve is invaded.

- CT can provide evidence of mediastinal invasion.

- Phrenic nerve paralysis high hemidiaphragm on chest X-ray.

*Cause of high hemidiaphragm in Br. carc.

- Phrenic nerve paralysis.

- Lower lobe collapse.

- Subpulmonary effusion.

- Liver enlargement (2ry to metastasis).

3.Pleural invasion:…….. pleural effusion

*Causes of pleural effusion in bronchial carcinoma :

a. Invasion of the pleura by tumor.

b. 2ry to lymphatic obstruction.

c. 2ry to associated pneumonia.

4. Chest wall invasion :

- The peripheral lung carcinoma may cross the pleura and invade the chest wall

causing rib or spinal destruction (+ Horners syndrome.)

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*Superior sulcus tumors (Pancost’s tumor)- mostly adenocarcinoma :

- Often have visible rib or spine invasion at presentation.

- Clinically may present with shoulder and arm pain due to chest wall invasion +

Horner’s syndrome due to invasion of the stellate ganglion (sympathetic).

N.B.: Rib destruction is the only sign that differentiates Pancost’s tumor from

other benign pleural cap lesion.

5.Blood metastasis : To :

- Suprarenal gland (common) or by “lymph spread”.

- Ipsilateral lung, ribs and spine.

6. Lymphangitis carcinomatosa.

7. Pulmonary osteoarthropathy.

Differences in radiographic patterns according to cell type :

1. Sq. cell carcinoma :

- A common central tumor giving rise to atalectasis.

- 1/3 of tumors arise peripherally, mainly attain a large size before being

symptomatic and often cavitate.

2. Large cell carcinoma :

- Either peripheral or central.

- Large mass cavitation is rare.

- Bronchus obstruction is second common presentation.

3. Small cell carcinoma (Oat cell):

- Often give rise to massive hilar or mediastinal adenopathy with a small or no

primary tumor could be detected.

- Atalectasis and or consolidation are common association with hilar mass.

4. Adenocarcinoma : (20%)

- Usually presents as an ill defined peripheral mass 4cm in diameter.

- Cavitation unusual .

- More common in upper lobes (pancost) .

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ALVEOLAR CELL CARCINOMA

(Bronchiolar or bronchio-alveolar carcinoma 5%)

It is a subtype of adenocarcinoma.:

C/P : Cough with production of mucoid sputum (mucus is produced by malignant

cells.

Radiologically : two forms

A. Local form:

-Often presents as a peripheral pulmonary nodule which is usually

indistinguishable from other cell types .

- Air bronchogram may be seen within a nodule, because the cells line the alveoli,

but do not compress air ways.

N.B: Lung carcinomas which show air bronchogram:

- Alveolar cell carcinoma.

- Lymphoma.

- Pseudo lymphoma.

B. Diffuse form: (rare)

- The lungs show widespread air space shadowing Unhomogenous

consolidation which may contain air bronchogram.

- Septal lines (A.B Kerley’s lines) and pleural effusion may be seen.

DD:

1. Pulmonary edema.

2. Widespread broncho pneumonia.

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CT : - Differentiates between it (?? The tumor) & lung collapse

- Detects small nodules.

- Detects effects (LN++, medist invasion, adrenals, liver).

MRI : * Size of tumor esp. close to hilar Vs

* T1 intermediate signal of tumor high signal intensity of surrounding fat.

* T2 collapsed lung has higher signal > tumor (high signal effusion.)

* Chest wall, ms, vascular, adrenal invasion ie local & distal spread.

ie. : Mass (esp. small & close to hilum) with intermediate intensity on T1 & high on T2.

Tomography.

*Summary

- Central mass + collapse + pneumonia DD LN

- Peripheral size, shape, edge, cavitation, calcification, bronchocele, tail

- Spread: Hilum, medist, chest wall, pleura, blood, lymphangitis + Pulmn osteoarthropathy.

- Alveolar cell (local, diffuse).

- Metastotic lung

- Lymphoma

NB: Increased size of the hilum:

1. Collapse

2. Vascular eg increase Pulmon. or aortic root

3. Lymph node: Met, TB, Lymphoma.

4. Central bronchogenic.

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METASTATIC TUMOURS

A. Pulmonary metastasis :

- Are due to haematogenous spread from breast, GIT, kidney, tests and from a

variety of bone and soft tissue sarcomas.

- Appear as, one or more discrete pulmonary nodules, which are usually spherical

and well defined but it may take any shape and may be irregular.

- A solitary metastasis may be a presenting feature without a known primary tumor.

- Solitary large cannon ball metastasis usually with renal cell carcinoma (hyper

nephroma).

- Cavitation may be seen particularly in metastasis, composed of squamous cell

carcinoma risk of pneumothorax.

- Calcification (rare) except in osteosarcoma and chondrosarcoma.

- Rate of growth is variable: Very rapid: osteosarcoma, slow: thyroid malignancy. .

B. Hilar and mediastinal node metastasis (see mediastinum)

C. Lymphangitis carcinomatosis :

- It is a from of metastatic carcinoma in which the pulmonary lymphatics are

invaded and blocked by cords of malignant cells.

- It may be unilateral or bilateral.

- The commonest causes are bronchial carcinoma, breast, stomach, colon, pancreas

and prostate.

- Bronchial carcinoma is ! commonest cause of unilateral lymphangitis

carcinomatosis.

Mechanism :

1. Lymphatic permeation, radiating from tumor in hilar lymph nodes.

2. Or it is probable that initial dissemination is via blood stream and invasion of

intrapulmonary lymphatics takes place with permeation of tumor towards hilae

and with no initial involvement of hilar lymph nodes.

Radiologically :

- Wide spread, ill defined 2-3 mm nodular pattern together with wide spread

thickening of the pulmonary septa.

- The fissures may be thickened by subpulmonary edema.

- Pleural effusion common but small. - Signs of associated lesion as bronchial carc.

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Lymphangitis carcinomatosis:

- Miliary Metastases.

- Lymphatic permeation.

- Interstitial fibrosis.

DD : Pulmonary edema.

Unusual pattern of metastasis :

Endobronchial metastasis :

- Unusual.

- Renal and colonic carc. are ! commonest primary tumor to give rise to

endobronchial metastasis.

- Radiologically : Effect of air way obstruction is the dominant feature.

Military metastasis :

- Miliary pattern with no evidence of lung masses or associated lymphatic obstr.

- The commonest causes are : (Thyroid, renal, trophoblastic carcinomas).

Pulmonary hypertension :

- Tumor emboli may block small pulmonary arterioles.

- Picture of pulmonary hypertension.

- It is a particular feature of choriocarcinoma.

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MALIGNANT LYMPHOMA

Primary pulmonary involvement by malignant lymphoma is usually accompanied by

mediastinal adenopathy. (Extension from hilar LN to lung by interlobular, perivascular &

peribronchial lymphatic channels deposits in intrapulmn. small node).

Radiological features:

1. Consolidation : resembling pneumonia.

- May be segmental or lobar in shape.

- It may radiate from hilum without confining to a segmental anatomy resembling

pulmonary edema.(mixture of linear streaks, bands and clusters of small nodules).

- Air bronchogram may be seen.

- Rapid increase in size of lymphomatous deposits mainly occurs with histocytic

lymphoma.

2. Pulmonary masses :

- Usually multiple with irregular smooth border + cavitation.

- May occur subpleural.

- Mainly occurs with lymphocytic lymphoma.

3. Diffuse lymphangitic form : (Kerley’s A and B lines)

- Common with histocytic lymphoma.

4. Miliary nodulation :

- May occur and indistinguishable from infection.

5. Associated features :

a. Lobar atalectasis : results from occlusion by endobronchial dis.

b. Pleural effusion.

6. Rib deposits: . Bone.

7. Pericardial effusion.

8. Radiation pneumonitis. + mediastinal adenopathy.

PDF to develop malig lymphoma :

1. Wiskott Aldrich Synd (cong immune deficiency). 2. Ataxia (telengectasia).

3. Autoimmune dis (Rhtoid, SLE, Myasthenia). 4. Occupational exposure: benzene.

5. Organ transplantation. 6. Phenytoin.

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Non-Hodgkin: * rarely starts in thorax.

* Common pulm. lesions without hilar lymphadenopathy.

Extranodal mucosa associated lymphoma ;

1. Sjogern synd, pseudolymphoma.

2. Lymphocytic interstitial pneumonia.

Leukemia :

- Microscopic infiltration of leuk cells around bronch & vessels & alvealor will.

- Mediastinal & hilar LN.

- Infection, infarction, pulmn. hge.

Other primary malignant tumors of the lung :

Compared to bronchogenic care :

- They are not related to smoking.

- Mainly affect young age.

- Have slow rate of growth.

1. Carcinoid tumors :

- Arise from APUD system (argentaffin cells).

- Central (bronchial obstruction – Extrabronchial mass).

2. ADENOID CYSTIC CARCINOMA (Cylindroma)

- Arise from trachea, carina or main stem bronchus.

- It is locally invasive and spreading to regional hilar LNS.

Radiologically :

A. Peripheral lesion (10%).

- Presented as, solitary, spherical or lobular nodule, with well defined smooth

edge. Average diameter 4cm and almost never calcify.

B. Central lesion (90%):

- The tumor arising from larger bronchi often have a larger mass lying outside the

bronchus than inside it, where this extrabronchial component may be visible as

a hilar mass.

- The endobronchial part, usually seen by tomography as, spherical or lobulated

endobronchial mass and unlike br. carcinoma, the adjacent bronchial wall is

smooth and there is no bronchial narrowing above the lesion.

- Diagnosis is confirmed by bronchoscopy.

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Signs of bronchial obstruction :

1. Atalectasis ± pneumonia or lung abscess.

2. Repeated infection bronchiectasis.

3. Bronchocele (Obstruction at segmental or subsegmental level).

3. Primary sarcoma of lung : (Rare)

- Affect young age.

- Nodal metastasis unusual and distal metastases is late.

- It may be central or peripheral.

- Radiologically : Large regular well defined mass.

BENIGN TUMOURS

A. Intrabronchial tumors :

1. Adenoma :- True adenomas are rare.

- This type does not include carcinoid or cylindroma.

- It is either (mucous gland adenoma, or mucoepidermoids).

2. Papilloma : Warty tumors, frequently multiple (papillomatosis).

3. Chondroma : Arise from bronchial cartilage.

4. Fibroma and lipoma :

B. Pulmonary tumors :

1. Hamartomas : It is composed of a mixture of tissues normally present in the lung,

including (cartilage and epithelial elements).

Radiographic features :

- Mainly appears as a solitary pulmonary nodule (90 peripheral, 10% central.)

- It is seen as a spherical or slightly lobulated, very well defined nodule , usually

< 4cm in size with normal surrounding lung.

- Calcification of the cartilage element is common, which may be, spotty, linear

or coarse irregular granularity - Popcorn calcification (characteristic).

- The density may be heterogeneous due to the presence of central lucencies which is

probably due to fat content .

- In central lesions (manifestations of major airway obstruction).

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2. Angioma :

a. Capillary haemangiomas.

b. Cavernous haemangiomas.

c. AV malformation.

- Often reveals multiple lesions.

- Spontaneous rupture (pulmonary haematoma).

- Draining vein + feeding artery.

3. Neurofibroma.

CAUSES OF SOLITARY PULMONARY MASS (v.imp)

1. Neoplastic :

1. Malignant : (1ry, metastasis, lymphoma)

2. Benign : (Hamartomas, neurofibroma)

2. Inflammatory:

1. Granuloma: TB, Histoplasmosis.

2. Chronic abscess.

3. Parasitic (Hydatid cyst), fungball.

3. Vascular :

1. Pulmonary haematoma.

2. Pulmonary infarction.

3. AVM.

4. Others :

1. Bronchogenic cyst.

2. Mycetoma (fungal ball).

3. Sequestrated lobe.

4. Rheumatoid

5. Outside :

Psendopulmonary mass (cutaneous mass, bony lesion, pleural “encysted effusion,

tumor plaque).

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Causes of intracavitary lesion in lungs :(same as solitary nodule but with

cavitation + cystic bronchiectasis + emphysematous bullae

A. Infective (Abscess)

- Staph. aureus and klebsiella.

- TB.

- Aspergillosis, Hydatid, amoebic.

B. Neoplastic :

- Bronchogenic carcinoma. (squamous)

- Metastasis.

- Lymphoma.

C. Vascular :

Infarction due to :

- 1ry infection (septic emboli) = pyemia.

- 2ry infection (of a non septic infarction).

D. Abnormal lung : (cong)

1. Cystic bronchiectasis.

2. Infective emphysematous bullae.

3. Sequestrated lung.

4. Bronchogenic cyst.

E. Granuloma ;

1. Sarcoidosis.

2. Rheumatic nodule.

3. Progressive massive fibrosis.(Pneumoconiosis)

F. Traumatic :

1. Haematoma.

MEDIASTINUM

Is situated between the lungs in the center of the thorax.

Boundaries :

Superiorly : Thoracic inlet.

Inferiorly: Central tendon of the diaphragm.

Anteriorly : Sternum.

Posteriorly : Thoracic spine.

Laterally: Parietal pleura.

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Radiological methods of investigation :

1. Standard high KV chest radiography.

2. CT is the best method. (for evaluation of hilar , mediastinal or paravertebral mass)

3. Conventional mediastinal tomography.

4. Barium studies.

5. Arteriography and venography.

6. Myelography.

7. Ultrasound.

8. Isotope scanning.

9. Fine needle aspiration biopsy either under fluoroscopic or CT guided control.

10. MRI.

ANTERIOR MEDIASTINAL MASSES

Located anterior to the pericardium and trachea :

Region I:

1. Retrosternal goiter.

2. Thymic tumors.

3. Aneurysm of ascending aorta.

4. Tortuous innominate artery.

5. Lymphangioma.

Region II:

1. Teratodermoid tumors (germinal cell neoplasms)./young adult-doesn’t displace trach.

2. Thymic tumors.

3. Sternal tumors (2ries, primary “chondrosarcoma, myeloma, lymphoma, giant

cell tumors”)

Region III :

1. Fat deposition and pericardiac pad of fat.

2. Morgagni hernia.

3. Pleuropericardial cysts.

4. Diaphragmatic hump.

5. Lipoma.

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THYROID TUMORS

Less than < 5% of enlarged thyroid glands in the neck extend into the mediastinum to

produce a retrosternal goiter.

Clinically :

- Soft tissue swelling that moves on swallowing.

- Dysphagia, stridor and superior vena cava compression syndrome in malignancy.

Radiographic features :

Plain :

- An oval soft tissue mass in the superior part of the anterior mediastinum, which

extends downward from the neck.

- The outline is well defined in the mediastinum but fades off in the neck due to its

anterior location.

- The mass commonly projects to the right side of mediastinum with displacement

and compression of the trachea to the left.

- In 20%, the goiters are retrotracheal posterior displacement of the esophagus

and the trachea.

- The mass may contain central nodular, linear or crescentic patterns of

calcification (not a sure sign).

CT: confirms the diagnosis :

Isotope scanning :

Shows an area of increased activity extending below ! sternal notch (diagnostic).

US: (Cystic / Solid)

Biopsy.

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THYMIC TUMOURS

The normal thymus gland is the commonest cause of a mediastinal abnormality

in infants. It produces a triangular soft tissue mass which projects to one side often the

right of the anterior mediastinum sail sign.( More prominent in expiratory or slightly

rotated film./ Absence in D’George’s synd : T lymphocyte immune deficiency disease). It may

disappear radiologically in the presence of severe neonatal pulmonary infection.

Thymic tumors include ;

1. Benign and malignant (30%) thymoma.

2. Hyperplasia of the gland: associates thyrotoxicosis, addison, SLE, arcomegally, Rhtoid.

3. Thymic cyst.

4. Thymolipomas.

5. Carcinoid tumors cushing synd., hyper PTH.

6. Thymic enlargement after radiotherapy for Hodgkin.

Presentation :

- Anterior mediastinal mass in non symptomatic adult patient.

- Myasthenia gravis in 10% of cases.

Radiographic features :

Plain :

- A round or oval soft tissue mass, projects to one side of the anterior mediastinum.

- It may contain a peripheral rim or central nodules of calcification.

- Thymolipoma : a very large soft tissue mass with less radiographic density which

changes its shape with respiration.

- Malignant thymoma pleural metastasis.

CT :

1. Shows a soft tissue mass in the anterior mediastinum which occasionally

contains calcium or cyst fluid.

2. Demonstrates the signs of invasion in malignant thymomas.

3. CT guided biopsy can confirm the diagnosis.

Lateral tomography :

Can show the outline of such a mass.

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TERATODERMOID TUMOURS

Germ cell tumors include :

- Dermoid cyst (ectoderm).

- Benign or malignant teratoma (ecto, meso, endo)

- Choriocarcinoma.

- Embryonal cell carcinomas

- Seminomas.

Origin :

- All are thought to arise from primitive germ cell rests in the urogenital ridge.

- About 70% of teratodermoid tumors are benign.

Presentation :

- Anterior mediastinal mass in an asymptomatic young adult patient.

- Dyspnea, cough and chest pain.

Radiographic features :

Plain :

A. Benign dermoid cyst :

- Appears as round or oval soft tissue mass, usually project to one side of anterior

mediastinum.

- The outline is well defined but becomes irregular in very large tumors due to

peripheral atalectasis in surrounding compressed lung.

- The mass may contain a peripheral rim or central nodules of calcification, a fat

fluid level or a rudimentary tooth which is a diagnostic sign.

B. Malignant teratoma :

- Appears as a lobulated soft tissue mass which projects on both sides of the

anterior mediastinum.

Computed tomography :

Solid mass of variable attenuation densities which contains soft tissue, cyst fluid,

calcium, bone or fat.

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LYMPHANGIOMA (CYSTIC HYGROMA)

Presentation :

- Soft tissue swelling that transilluminates in the root of the neck in children.

Radiographic features :

1. Plain :

- Appears as an oval soft tissue mass in the superior part of the anterior

mediastinum which extends up into the neck.

- It can alter in shape on respiration, but does not displace the trachea.(DD: goitre)

2. CT confirms the diagnosis :

- Cystic swelling.

- Fluid density.

FAT DEPOSITION

- Excessive deposition of fat in the mediastinum usually presents with widening of the

superior part of mediastinum and large epicardial pad of fat in asymptomatic obese

patient + Cushing.

- Diagnosis is confirmed by CT :

- DD :

1. Mediastinal lymphadenopathy.

2. Dissecting aortic aneurysm.

PLEUROPERICARDIAL CYST

Presentation : An anterior or middle mediastinal mass in asymptomatic adult patient.

Radiological features :

1. Plain :

- A round, oval or triangular soft tissue mass in the anterior or middle mediastinum

which alters its shape on respiration.

- About 75% of pleuropericardial cysts occur in right anterior cardiophrenic angle.

2. CT :

- Thin walled cyst containing fluid of low attenuation (0-10 H.U.) = Spring water

cysts.

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DD from masses in the right cardiophrenic angle :

1. Epicardial fat pad.

2. Morgagni hernia (may contain gas).

3. Right middle lobe opleural pathology.

4. Partial eventration of the right hemidiaphragm.

5. Right atrial or pericardial tumors.

6. (Hiatus hernia, Achalasia, Bronchogenic cyst, Epiphrenic diverticulum).

3. Direct needle puncture and aspiration under CT or US guidance.

NB: Masses that alter their shape with respiration

1. Thymolipoma. 3. Pleuropericardial cyst.

2. Lymphangioma. 4. Lipoma.

MORGAGNI HERNIA

Anatomy :

- The foramen of morgagni is a persistent developmental defect in the diaphragm

anteriorly between the septum transversum and the costal origin of the

diaphragm.

Presentation :

- An anterior mediastinal mass in an asymptomatic adult patient.

- The hernia can produce retrosternal chest pain, epigastric pain and dyspnea.

- More than 90% of morg. hernias are situated in the right anterior cardiophrenic

angle due to the protective affect of the pericardium on the left.

Small hernias :

- Contains omentum, which appears as a rounded soft tissue mass.

Large hernias :

- Contain small or large bowel or stomach.

- Appear as soft tissue mass containing either gas or gas fluid levels.

- Barium studies (meal, follow through and enema) confirm the diagnosis e.g. a

loop of transverse colon above the diaphragm and within the chest.

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PARATHYROID ADENOMA (rare)

Presentation :

- An ectopic parathyroid gland in the chest.

- Usually presents with hypercalcaemia in an adult patient with hyper-

parathyroidism.

Radiological features :

- Plain chest normal.

- Abdomen nephrocalinosis or renal calculi.

- Skeletal changes of hyperparathyroidism.

The diagnosis is confirmed by isotope scan.

LIPOMA

Plain : A round or oval soft tissue mass with radiographic density and can alter in

shape on respiration.

CT : Solid mass of fatty attenuation (-50 to - 100 H.U.)

MIDDLE MEDIASTINAL MASSES

1. Lymph node enlargement.

2. Aortic aneurysm.

3. Dilatation of mediastinal veins.

4. Bronchogenic cyst.

5. Vascular anomalies.(RT. Sided Aortic Arch, Dilated main pulm, Coarctation)

6. Tracheal tumors.

7. Tracheomalacia.

MEDIASTINAL LYMPH NODE ENLARGEMENT

Enlargement of the paratracheal, tracheobronchial, bronchopulmonary (hilar) and

subcarinal groups.

Causes :

1. Metastatic deposits 4. Sarcoidosis 7.Histoplasmosis + coccidioidomycosis

2. Lymphoma 5. Tuberculosis.

3. Leukemia. 6. Other infections and granulomas silicosis + amyloidosis

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Metastatic diseases :

- Intrathoracic (bronchial carc., cancer oesoph).

- Extrathoracic (breast, renal, adrenal, testicular, pharyngeal, laryngeal, thyroid).

Bronchial carcinoma :

- Is the commonest primary tumor to metastasize in mediastinal LN.

- It produces either:

* Unilateral hilar mass with an irregular lobulated outline.

* Widening of superior part of middle mediastinum due to a superior vena caval

compression syndrome.

Esophageal carcinoma :

- May involve the posterior mediastinal lymph nodes.

Renal and adrenal tumors :

- Can metastasize to the right hilar LNs.

Testicular tumors : Paratracheal L.N.

Lymphoma :

- Usually involves the paratracheal and tracheobronchial lymph nodes producing

asymmetrical bilateral widening of the superior part of the middle mediastinum.

- Involvement of subcarinal lymph nodes splaying of the carina.

- Peripheral calcification occasionally occurs in the lymph nodes egg shell

calcification.

Primary TB :

- Produces an area of consolidation in one of the lobes and a unilateral hilar

enlargement.

- Calcification may develop in both primary Ghon’s focus and mediastinal lymph

nodes as healing occurs.

Fungal infections :

- Such as Histoplasmosis and coccidioidomycosis.

- May produce enlargement of the hilar or paratracheal lymph nodes.

- Calcification may occur in healing stage.

- Actinomycosis is ! only fungus causing unilateral hilar lymphadenopathy : USA.

??Also :Infections mononucleosis. Adenoviruses. Mycoplasma

Measles, whooping cough. Pyogenic lung.

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ANEURYSM OF THORACIC AORTA

Causes in cardiovascular :

Presentation :

- Chest pain radiating to back (dissecting).

- Hoarseness of voice due to traction on Recurrent laryngeal Nerve.

- Dysphagia.

Radiological features :

Plain :

a. Widening of the mediastinum.

b. A round or oval soft tissue mass in any part of mediastinum with a well defined

outline.

c. Sometimes a peripheral rim of calcification.

d. May also involve adjacent bones producing :

1. Pressure erosion of the sternum.

2. Anterior scalloping of one or two vertebral bodies.

Fluoroscopy :

- Pulsatile masses are not a sure sign, because any mass adjacent to aorta transmits

its pulsation.

Thoracic aortography (& DSA, MRI )

- Confirm the diagnosis except if the aneurysm is thrombosed.

Computed tomography :

- Shows a dilated aorta containing a central lumen of blood of high attenuation

(80-100 H.U.) due to enhancement of the blood pool with water soluble contrast

medium (true).

- A peripheral layer of clot of lower attenuation which may contain calcification

(false lumen). The subintimal flap and false lumen of a dissecting aneurysm can

be demonstrated by CT.

TORTUOUS INNOMINATE ARTERY

Produces widening of the superior part of ! mediastinum on the right side without

displacement of the aorta

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DILATATION OF THE MAIN PULMONARY ARTERY

Can produce an apparent left hilar mass, through which the hilar vessels can be seen.

RIGHT SIDED AORTIC ARCH

Fallot’s in cardiovascular system.

DILATATION OF MEDIASTINAL VEINS

Dilatation of superior vena cava produces widening of the superior part of the

mediastinum on the right.

Causes of S.V.C dilatation : = Causes of increased central venous pressure:

1. Congestive H. failure.

2. Tricuspid valve disease

3. Constrictive pericarditis.

4. Cardiomyopathy.

5. Rt atrial tumors.

6. Mediastinal masses (compress the SVC)

Dilatation of azygous vein: produces an oval soft tissues mass in right

tracheobronchial angle.

DD : LN enlargement: although azygous vein alters in size with change in position or

during valsalva.

Causes :

1. Same cause of increased CVP.

2. Portal hypertension.

3. Obst. of SVC or IVC.

4. Cong azygous continuation of IVC.

Diagnosis : is confirmed by venacavography & CT.

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BRONCHOGENIC CYST

Age : Children, Young adults.

C/O : Asymptomatic, stridor in children, cough, dyspnea, chest pain.

The majority of bronchogenic cysts occur around the carina, paratracheal,

Tracheobronchial (hilar), subcarinal regions.

Radiological Features:

Plain :

- A round or oval soft tissue mass in the middle mediastinum frequently on the

right side near ! carina.

- Rapid increase in its size indicates internal hemorrhage.

- An air fluid level is present after rupture of an infected cyst into the bronchial

tree.

CT :

- A mass of soft tissue attenuation (10-15 H.U.)

Tracheal tumors: (rare)

Radiologically :

- Narrowing of the tracheal lumen by a soft tissue mass.

- The diagnosis is confirmed by tomography and CT.

POSTERIOR MEDIASTINAL MASS

Region I (Paravertebral):

1. Neurogenic tumors.

2. Other paravertebral masses.

3. Anterior thoracic meningocele.

Region II :

1. Dilated esophagus.

2. Aorta unfolded, dilated or aneurysmal.

3. Neuroenteric cyst.

4. Enteric cyst : is an intestinal duplication cyst related to oesoph.

Region III :

1. Hiatus hernia. 2. Bochdalek hernia.

3. O: Pseudopancreatic cyst, extra medullary haemopoietic system

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NEUROGENIC TUMORS

Adult : (Neurofibroma, neurilemmoma “Schwannoma”) arise from peripheral inter

costal nerves. (paravertebral gutter)

Child : (Ganglioneuroma, Neuroblastoma) arise in the thoracic sympathetic ganglia.

Others : (Neurofibrosarcoma, Pheochromocytoma).

Occurs in the paraganglionic nerve tissue.

N.B. About 30% of neurogenic tumors are malignant.

Presentation :

- Posterior mediastinal mass in asymptomatic child or young adult.

- Back pain.

- It may extend through an intervertebral foramen into the spinal canal (hence their

name “dumbbell tumors) spinal canal compression syndrome.

Radiological features :

1. Plain x-ray :

Neurofibroma :

- Neurogenic tumor appears as a round or oval soft tissue mass with well defined

outline in the paravertebral gutter which project to one side of posterior

mediastinum.

- Enlargement of the intervertebral foramen = dumbbell shaped tumor.

- May be part of multiple neurofibromatosis = Von Reklenhousen disease.

Ganglioneuroma :

- A rather elongated soft tissue mass in comparison to the more circular shape of

Neurofibroma.

Neuroblastoma :

- May contain central spicules or a peripheral rim of calcification.

NB: Neurogenic tumors may involve the posterior ribs or adjacent thoracic vertebra.

The benign N. tumors can produce :

- Splaying of several posterior ribs. - Rib notching.

- A localized pressure erosion defect of one or two vertebral bodies.

The malignant N. tumors can produce :

- Bony destruction.

- Rapid increase in size of the mass. - Pleural effusion .

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2. Computed tomography :

- A solid mass of soft tissue attenuation, which may contain calcification and may

involve the adjacent bones.

3. Myelography :

- Can demonstrate intraspinal extension.

NB: MRI is superior > CT (better soft T contrast).

PARAVERTEBRAL LESIONS

Common causes of paravertebral mass :

1. Neurogenic tumors.

2. A traumatic wedge compression fracture of a vertebral body with heamatoma

formation.

3. A pyogenic or tuberculous paraspinal abscess.

4. Multiple myelomas.

5. Disseminated lymphoma and metastatic carcinoma with paraspinal extension.

6. Extramedullary haemopoietic tissue.

Radiological features :

- An elougated or lobulated soft tissue shadow with a well defined outline, usually

projects on both sides of the posterior mediastinum.

- Involvement of adjacent thoracic vertebrae or intervertebral disc spaces.

DD :

1. Inflammatory lesion (narrow disc space, bone destruction).

2. Neoplastic lesion (only bone destruction).

The diagnosis can be confirmed by :

1. Penetrated P film. 2. Lateral film.

3. Conventional tomography. 4. CT + CT guided biopsy.

HIATUS HERNIA

Presentation :

- Posterior mediastinal mass in asymptomatic elderly patient.

- Dyspnea, retrosternal chest pain and epigastric discomfort.

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Radiological features :

1. Plain :

- A round soft tissue mass containing an air fluid level directed behind ! heart.

- In 70% it lies to the left of midline in the posterior mediastinum.

2. Barium meal :

- Shows the stomach above the diaphragm and within chest.

OESOPHAGEAL LESIONS

1. Pharyngoesophageal pouch (Zenker’s diverticulum)

Plain :

- Round soft tissue mass in sup part of post mediastinum containing air fluid level.

- Forward displacement of trachea.

2. Cancer esophagus :

3. Mega esophagus :

1. Achalasia of the cardia.

2. Benign esophageal stricture.

3. Cancer esophagus.

4. Presby esophagus.

5. Systemic sclerosis.

Radiological features :

*Plain :

- Widening of the posterior mediastinum behind ! heart on the right extending

from the thoracic inlet to the diaphragm.

- An air fluid level in the superior part of the posterior mediastinum with non

homogenous mottled appearance of food particles mixed with air.

- No air in the fundus of stomach.

*Barium swallow :

- Confirms the diagnosis.

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BOCHDALEK HERNIA

Anatomy :

The foramen of Bochdalek is a persistent developmental defect in the

diaphragm posteriorly produced by a failure of the pleuro-peritoneal canal membrane

to fuse with the dorsal esophageal mesentery medially and the body wall laterally.

Presentation :

- Posterior mediastinal mass in asymptomatic adult patient.

- Acute respiratory distress in neonatal period.

Radiological features :

- About 90% of Bochdalek hernia occur in the left hemidiaphragm due to !

protective effect of liver on ! right .

1. Plain :

- Small hernia: usually contain retroperitoneal fat, kidney or spleen.

appears as a soft tissue mass posterior costophrenic angle.

- Large hernia:

* contains small or large bowel

* appears as multiple ring shadows in the chest due to air filled loops of

bowel.

* Displacement of the ! heart and mediastinum to the contralateral side.

* Ipsilateral lung is invariably hypoplastic.

2. Barium:

3. U/S

4. I.V. Urography :

Can also confirm diagnosis by showing liver, spleen or kidney above diaphragm.

N.B: 13 pairs of ribs may occur in association with a Bochdalek. hernia.

NEUROENTERIC CYSTS

Etiology :

- Partial or complete persistence of neuroenteric canal + vert anomalies.

- Incomplete separation of foregut from the notocord in the embryonic life.

- The cysts are often connected to the spinal meninges and to ! G.I.T.

NB: Enteric cyst: Intestinal duplication cyst related to ! esophagus + no vertebral anomalies.

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Presentation :

- Respiratory distress or feeding difficulties in infants.

- Chest pain in young adult, if peptic ulceration occurs within it.

Radiological features :

1. Plain :

- A round or oval soft tissue mass in the posterior mediastinum between the

esophagus and the spine causing forward displacement of the esophagus.

- An air fluid level is present after rupture of an infected cyst in ! esophagus.

2. Computed tomography :

- A mass of soft tissue attenuation.

ANTERIOR THORACIC MENINGOCELE

1. A well defined mass anterior to spine and projects into lung field.

2. The spine show hemivertebra.

3. Diagnosis is confirmed by myelogarphy in prone position.

4. In patients with Neurofibromatosis

PSEUDO PANCREATIC CYST Presentation :

- The cyst extending through the esophageal or aortic hiatus into the chest

dyspnea, dysphagia.

Radiological features :

1. Plain :

- A round or oval soft tissue mass behind ! heart.

- Left basal pleural effusion or atalectasis.

2. Computed tomography :

- Thin walled cystic mass containing fluid (0-20 H.U.) extending from abdomen

into chest through aortic hiatus behind the diaphragmatic crura.

EXTRAMEDULARY HAEMOPOIETIC SYSTEM

Causes : Chronic hemolytic anemia (Thalassaemia major)

Radiological features :

- It appears as a lobulated paravertebral soft tissue mass behind ! heart.

- Abdomen film: hepatosplenomegaly. - Typically abnormal skeletal survey

(see bone).

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PNEUMOMEDIASTINUM

Incidental, asymptomatic or chest pain which worsens by breathing .

Air tracks up to neck surgical emphysema.

Causes :

1. Perforation of esophagus osophoscopy or Mallory-Weiss.

2. Rupture of trachea bronchoscopy or trauma.

3. Asthma, IPPV.

4. Whooping cough.

5. Pneumoperitoneum.

Radiologically :

Plain :

- Translucent streaks of gas outlining bl.Vs & other structures with displacement

of the parietal layer of the pleura laterally.

- Lateral film air behind sternum or heart.

Acute mediastinitis :

- Chest pain + fever.

- Mediastinum is widened & edematous houtline.

- Pleural effusion.

- Occasionally abscess.

Chronic mediastinitis (mediastinal fibrosis)

- Presents with SVC compression.

- Common with radiotherapy, TB, Reidles thyroditis, idiopathic retroperitoneal

fibrosis

- Plain: wide medistinum

- SVC cavography , DSA: retrograde filling of dilated veins such as ! jugular,

azygous & internal mammary veins.

Mediastinal hemorrhage :

- Trauma

- Leaking aortic aneurysm.

- Plain: widened medistinum, spinal fracture, pneumo or hydrothorax.

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PNEUMONIAS

Pneumonia:

Infective consolidation of the lung (replacement of alveolar air by exudate).

(Pathogenic organism)

Pneumonitis :

General term= inflammatory reaction of the lung ± consolidation.

Alveolitis on interstitial pneumonitis:

Inflammatory process mainly affecting the alveolar wall.

Bronchopneumonia :

Multifocal (bronchocentric) infection based on the pulmonary lobule & spreads

along the bronchial axis.

DIFFERENCE BETWEEN LOBAR AND BRONCHOPNEUMONIA:

I- Lobar pneumonia :

Pathology :

1. Unifocal. 2. Centered on distal air spaces (alveoli).

3. Rapid spread across the pores of khon uniform consolidation.

4. Spare distal airway.

Radiologically :

1. Homogenous non segmented consolidation.

2. As airways are not involved & remain patent, so there is no volume loss & air

bronchogram is common.

II- Bronchogenic pneumonia :

1. Multi focal. 2. Centered on air ways.

3. Spread along bronchial axis.

4. Air way obst. atalectasis & pneumatoceles.

5. Affected by bronchiolitis so initially patchy &distributed in course of air ways so it is

segmental.

Radiologically :

1. Non homogenous segmental consolidation.

2. May become uniform with confluence later.

3. Air bronchogram is usually absent. 4. Volume loss is common.

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ACUTE PNEUMONIA

Etiology :

A. Bacterial causes :

1. Pneumococci (streptococcus pn). most common

2. Loss common :

- Staph. aureus.

- Gram -ve organisms.

a. Pseudomonas. d. Legionella pneumophilia.

b. Klebseilla Freidlenders. e. E coli & proteus.

c. Haemophlus influenza.

3.Anaerobic organisms.

B. Non bacterial causes :

- Mycoplasma pneumonia : most common.

- Viral eg influenza & varicella.

- Ricketsial pneumonia.

- Chlamydial pneumonia.

NB: All cause bronchopneumonia except Pneumococi (basal) & Klebseilla (apical) cause lobar

Pneumococcal (Strept.) Pneumonia :

Age : Extreme of age (occurs at any age).

Predisposing factors: (Chronic illness, alcoholism, splenectomy).

Radiological features :

- Initially peripheral, non segmental, homogenous consolidation limited by fissure.

- Commonly basal and solitary, but it may occur any where and also may be

multifocal.

- Consolidation may not be obvious and suspected by silhouette sign of boundary

effacement.

- Air bronchogram is commonly present (characteristic).

- Kerley’s B lines may appear in affected area from temporary over loading of

lymphatics and edema of the interlobar septa.

- No volume loss of the affected lobe.

Complications : (not common unless treatment is delayed.)

1. Empyema, effusion / 2.Cavitation (lung abscess) rare./ 3. Delayed resolution.

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STAPHYLOCOCCUS PNEUMONA:

PDF :

1. Debilitated hospitalized patients.

2. Aspiration from URTI (common).

Radiologically :

- Consolidation is classically segmental & patchy at least initially but later

confluent & homogenous.

- Often, Multifocal & bilateral.

- volume loss is common.

- Air bronchogram is unusual.

Features of complication :

1. Due to strong tendency for necrosis that occur in the center of staph.

consolidation cavitation and abscess formation.

2. Rupture of cavity in pleura empyema.

3. Pneumatocele formation: Occurs when consolidation and fluid content of the

abscess cavity are resolved leaving thin hair-line walled air cavities, which

mainly persists for months or disappear leaving no trace.

4. Septicaemic staph pneumonia multifocal, nodular consolidation.

5. Collapse.

PSEUDOMONAS AERUGINOSA:

- Pulmonary infections follow mechanical ventilation or inhalation therapy

- Mainly affects the lower lobes and its radiological pattern is similar to staph

aureus infection.

H. INFLUENZA:

- Mainly associated with chronic lung disease is chronic bronchitis or secondary

invader in influenza virus infection.

- Has no characteristic radiographic pattern.

KLEBSIELLA OR FRIEDLANDER’S PN:

- Middle aged & elderly debilitated persons.

- Similar to strept pneumonia.

- Homogenous well demarcated unifocal consolidation.(Lobar)

- Upper lobes.

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- Consolidation is voluminous by inflammatory exudation, so the affected lobe

may be swollen & fissures may bulge. - Rapid cavitation, septicemia.

LEGIONNAIRES DISEASE (Legionella pneumophilia)

- Common in ♂, mainly occurs in epidemic & associated with contaminated water.

Clinically :

- Similar to bacterial pneumonia and sometimes associated with G. intestinal and

neurological features.

Radiologically :

- Initially there is a unilateral peripheral lower zone consolidation rapid

progression with confluence and or spread of consolidation to other lobes of

same or opposite side.

Complications:

- Effusion 50%.

- Cavitation, abscess and pneumatocele.

- Characteristically, resolution tends to be slow over several weeks but usually

complete.

ANAEROBIC PNEUMONIA

Differs from other bacterial pneumonia in that :

1. Often clinically subacute or chronic with prominent systemic symptoms.

2. Results commonly from aspiration of infected oral contents.

Radiologically :

- Consolidation is uni or multifocal & tends to occupy segments favored by

aspiration eg (posterior upper / Apical lower/ postero basal), more on the RT

side.

- Homogenous, but usually cavitation lung abscess.

- Empyema is common bronchopleural fistula.

MYCOPLASMA PNEUMONIA:

Mycoplasma pneumoniae is an organism intermediate between bacteria and virus.

It is one of organisms produce primary atypical pneumonia which are:

Causes of primary atypical pneumonia :

1. Adenovirus. 4. Toxoplasma.

2. Psittacosis - Chlamydial 5. Mycoplasma

3. Q fever = Rickettsial.

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PRIMARY ATYPICAL PNEUMONIA :

Radiologically of changing pattern :

- Initially, fine reticulation due to interstitial inflammation followed by

consolidation of involved area, usually segmental or lobar.

Other possible patterns :

- Multiple irregular patches with ill defined margins.

- Multiple small well defined nodules.

- Fulminating fibrosing alveolitis.

- Massive bilateral bronchopneumonia with abscess formation.

- On resolution, the process is reversed.

- Resolution tends to be slower than bacterial pneumonia.

VIRAL PNEUMONIA:

- Common in infants and children.

- In adult, viral pneumonia may be primary as in influenza, or as a part of

generalized viral illness in varicella.

- Radiologically: wide spread nodules, interstitial streaks from hila, mediastinal &

hilar adenopathy.

INFLUENZAE

Predisposing Factors: old age, debilitated persons.

Radiologically :

- It begins a few days after the onset of symptoms.

- Extensive bilateral confluent consolidation which if patient survives, may be

be followed by fibrosis.

VARICELLA

Typically affecting young adults.

Predisposing f: Lymphoma, pregnancy.

Radiologically:

- Characteristically, widespread 5-10 mm nodules, which may simultaneously

come and go in different areas.

- Nodules, usually resolve in a week but it may persist.

- 20% of the opacities calcify.

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RICKETSIAL PNEUMONIA:

The most common ricketsial lung infection is Q fever, which is caused by coxiella

burnetti, which is mainly acquired from sheep and cattle.

Radiologically :

- One or more rounded segmental consolidations in the lower zone.

- Linear areas of collapse (common).

- Resolution mainly slow.

CHLAMYDIAL PNEUMONIA:

The commonest lung infection is ornilhosis caused by chlamydia Psittaci, which is

acquired from sick birds.

Radiologically :

- Variable pattern: lobar, patchy or miliary consolidation.

- Slow resolution.

ASSOCIATED FEATURES AND LOCAL COMPLICATIONS

OF PNEUMONIA:

A. Effusion: most common with anaerobes , gam-ve ligonella, staph & strept.

B. Empyema: staph aureus, strept, anaerobes

Rad: indistinguishable from effusion, suspected when large, delayed in app.,

unusual dist., or when associated with fluid level abscess.

C. Hydropneumothorax: Iatrogenic or rupture of pneumotocele or abscess or br.pl.

Fistula. (staph, gram-ve)

D. Localized transradiancies:

1. Abscess formation :

- Factors in favor : 1. Aspiration of infected material.

2. Infection by specific material.

3. Infection by anaerobic organisms.

- Abscess is within area of consolidation, communicates with airway & contents

are discharged with resultant air fluid level formation.

- Causes: A. Staph aureus :

* Usually multiple. * No lobar predilection

* Thick walled with raged inner lining.

* Associated with A, B, & C & pneumatoceles.

B. Tuberculosis.

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C. Gram-ve, fungal, hydatid, amebiasis

D. Klebsiella :* Usually single. * Thick walled.

* More common in upper lobe.

2. Pulmonary gangrene :

- Pneumonia thrombosis of intrapulmn Vs gangrene to pulmn. area supplied

by these Vs.

- Suspected when a large irreg. cavity develops, containing an irregular

intracavitary body.

- Most common with Klebseilla pn. & strept.

3. Pneumatocele :

- Occurs when consolidation & fluid content of an abscess cavity are resolved,

leaving thin hair-line walled air cavities which mainly persist for months or

disappears leaving no trace.

- Septicemic staph pneumonia multifocal, nodular consolidation.

- Underlying disease eg sequestrated segment, bronchogenic cyst, cavitary

neoplasm, bronchiectasis.

E. Lobar expansion :

- Mainly with Klebseilla pneumonia.

F. Collapse :

- May be seen in resolution phase (esp children) .

- With agents that initially bronchitis or bronchiolitis eg staph aureus.,

rickettsia.

G. Residual scarring :

- Parenchymal & pleural scarring “fibroses” with volume loss.

Pneumatocele :

Def.: cyst in lung during course of pneumonia (staph aureus).

Cause : tension cyst d.t partial obst. of small branches.

Site : in area of consolidation

Size : variable.

Shape : hair line wall - full of fluid.

Number : multiple or solitary.

Course : resolve.

Compl. : pneumonia + empyaema.

DD : hernia

Emphysematous bullae ( its wall is made of surrounding compressed lung tissue)

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RESOLUTION

90% of bacterial (except TB) and non bacterial pneumonias resolve within one month.

When changes persist beyond two months delayed resolution.

Causes of delayed resolution :

1. The commonest : old age, systemic disease.

2. Very extensive consolidation or complicated with cavitation, empyema or

atalectasis.

3. Presence of predisposing local cause e.g. bronchiectasis or air way obstruction.

4. Inappropriate therapy e.g. TB, mycosis.

5. Repeated aspiration: chronic sinusitis, achalasia or hiatus hernia.

N.B:

* Mendelson’s syndrome :

Chemical pneumonia, caused by aspiration of acid gastric contents during anesthesia

producing intense bronchospasm which is rapidly followed by pulmonary edema.

* Young’s syndrome :

Obstructive azospermia / Sinusitis / Chr. pulmonary infecting eg. bronchiectasis.

Pneumonias (KEY):

PDF/AGE/Complications A,B,C,D,E,F,G & resolution./Path & Rad.

Lobar

1. Unifocal

2. Centered on air spaces

3. Khon consolidation

4. Spare distal air ways

↓

- Homogenous non seg

- No volume loss

- Air bronchogram

BronchoPneumonia

1. Multifocal

2. Centered on airways.

3. Spread along bronchial

4. Airway obst.

↓

Non homogenous, segmental (late confluece)

volume loss (atalectasis)

no air bronchogram

Strept lobar + kerly’s b dt fissure edema, prep & basal

Staph Br. Pn. + necrosis & cavitation + pneumatoceles++, septicemia.

Pseudomonas Br. Pn. + lower lobes+ in pt with mechanical ventilation

H. influenza Br.Pn.+ associated chronic lung dis viral

Klebseilla (fredlender) lobar+ upper lobe + voluminous inflm exudate.

Legionella male epidemic, water + GIT & CNS features + preph lower zones.

Anaerobic Br. Pn., occupy segments favored by aspiration.

Mycoplasma Atypical pneumonia : also: Q Ricketsial & chlamydial

Viral viral symptoms + Bilat fibrosis + nodules, streaks & LN.

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FUNGAL INFECTION

A. Pulmonary Histoplasmosis :

Caused by histoplasma capsulatum (soil dust)

1. Benign primary form :

- Initially, pulmn. focus is not identified & main sign is hilar or mediastinal

lymphadenopathy.

- With healing calcification of initial pulmn focus/ lymph nodes.

- Calcified LN may extend into! bronchi, where they are known as broncholiths

bronchial obst.

- In few cases: mediastinal fibrosis constriction of major Vs: SVC & pulmn.Vs

.

2. Chronic pulmonary form :

A. Histoplasma granuloma :

- Rounded nodule < 2cm.

- Usually well defined edges

- Irregular: difficult to distinguish from primary carcinoma.

- presence of central calcification is diagnostic.

B. Chronic fibrocavitary form :

- Indistinguishable from fibrocavitary TB.

3. Acute inhalation histoplasmosis :

- Inhalation & soil dust contaminated by bird droppings.

- Widespread small consolidations us may calcify chch pattern of innumerable

small calcifications distributed throughout ! lungs.

B. Coccidioidomycosis : Caused by coccidia fungus :

I. Patchy consolidation :

- Mainly lower lobes.

- Cavitation thin wall cavities (grape skin).

- Pleural effusion. / mediastinal LN.

II- Nodular form :

- Nodules (multiple or single) up to 3cm.

- Mainly upper lobes.

- Cavitation thin wall cavities (resembles TB) DD: miliary TB.

- Calcify.

- Rare : Miliary pattern due to blood dissemination.

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C. Actinomycosis :

- Commensal in oropharynx (normally):

Aspiration lower lobe pneumonia (dependant) abscess formation,

empyema, rib osteomylitis

- Sinuses open on skin yellow sulfur granules.

D. Aspergillosis :

Aspergillus fumigatus fungus. Three forms :

1. Pulmonary mycetoma (Aspergilloma)

- Here ! fungus is present as a saprophyte where ! fungal hyphae are matted

together in ! form of a ball in a pre existing lung cavity (eg TB, histoplasmosis,

Sarcoidosis, cong. lung cyst, cavitary bronchogenic carcinoma).

- Common in upper lobe.

- Mycetoma mainly doesn’t appear in CXR dt high opacity of fungus ball with

thickening of the adjacent pleura.

- Diagnosis is established by (CT, tomography) that reveales the fungus ball

delineated by a crescent of air (halo sign).

DD :

1. Blood clot in a cavity. 3. Simple lung abscess.

2. Cavitary sq. cell C. 4. Disintegrated hydatid cyst.

2. Invasive aspergillosis :

- Pneumonia in immunocompromised pt.

- No characteristic radiological pattern :

* Necrotizing bronchopneumonia with abscess formation.

* Single or multiple nodules (1-5cm) which may cavitate.

* Organizing lobar pneumonia.

* It can mimic with an aspergilloma ..... The difference is that it develops in

an apparently previously normal lung tissue.

3. Allergic, bronchopulmonary, aspergillosis :

- A hypersensitivity reaction, which occurs in ! major airways of some asthmatics.

- It is associated with blood eosinophillia, increased serum IgE, and +ve skin

reaction to aspergillus.

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Radiologically :

A. Acute changes :

- Consists of non segmental areas of consolidation, common upper lobe (loffler $).

- Lobar collapse.

- Branching thick tubular opacities due to distended bronchi with mucus and

fungus (bronchocele).

B. Chronic changes :

- Consists of bronchial wall thickening with tram line shadows.

- Ring formation indicative of bronchiectasis .

- Linear shadows indicative of fibrosis.

E. Moniliasis (candidiasis) : (rare)

Caused by candida albicans (normal month community).

- The pulmonary lesion is a chronic pneumonia which breaks down with abscess

formation.

- Mycetoma may develop in abscess cavity indistinguishable from

aspergilloma.

F. Blastomycosis :

- Asymptomatic nodule. - Chronic pneumonia.

- Potential for re-activation. - Node enlargement.

PARASITIC PULMONARY INFECTIONS

A. Tropical pulmonary eosinophillia (Filariasis) :

Pulmn. allergic response (eosinophillic interstitial infiltration / intraalveolar exudate).

Radiologically:

- Subtle bilateral midzonal haze.

- Small ill defined migrating nodules (0.5cm) : scattered.

- Severe snow storm picture.

- Streaks radiating from hila & peripheral. reticulations.

N.B: Loffler’s synd = applied to almost any transient pulmn. opacities of a

predominately eosinophillic histology associated with blood eosinophillia.

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B. Schistosomiazis :

- Eggs lodge in small pulmn. Arteries (100 m) small granulomas like TB.

- If lodge in large arteries irritation vas. necrosis fibrotic occlusion

pulmn. hypertension (Ayerza dis).

- Diffuse interstitial fibrosis.

C. Protozoa :

1. Pleuropulmonary amoebiasis :

Usually secondary to liver amaebiasis, young adult male .

Radiologically:

- Elevation of hemidiaphragm, pleural effusion / or thickening.

- Basal band shadow (discoid atalectasis).

- When liver abscess erodes ! diaphragm basal non segmental consolidation

cavitates & fistulae develops between air way & pericardium.

- Blood spread consolidation or abscess in part away from ! diaphragm.

Diagnosis :

1. US liver.

2. Serological test.

3. Also aspiration biopsy guided by U/S is valuable.

2. Toxoplasmosis :

- Human acquisition is from cats.

- Presented as primary atypical pneumonia and mediastinal lymphadenopathy.

3. Pneumocystitis carinii infection :

Only expressed in immunocompromised patients.

Radiologically :

- Diffuse bilateral pulmonary opacification like pulmonary edema, homogenous

with air bronchogram.

- Focal emphysema may occur, where multiple air cysts with air fluid level may

be seen, which may complicate with pneumothorax and pneumomediastinum.

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D. Hydatid Disease :

Infection with the tape warm Echinococcus granuloses.

Radiologically :

The cyst is unilocular, smoothly spherical and of homogenous density,

calcification is rare.

Complication :

- Infection

- Rupture:

* into ! pleural cavity or a bronchus.

* Partial replacement of fluid by air (fluid level.)

* Rupture of a liver cyst into ! right lung produces a basal opacity from lobar

infection or atalectasis-pleural effusion.

TC99m labelled IDA hepatic defect.

CONGENITAL PULMONARY SEQUESTRATION

Definition: a portion of the lung is separated from the normal bronchial tree & blood

supply, though retaining some characteristics of lung tissue.

Divisions :

1. Intralobar : lying within the lung, usually posteriorly in left lower lobe. Rt.

lower lobe is the next most common site.

Radiological appearance:

Plain:

* Soft tissue mass in posterior part of lower lobe close to the diaphragm

(> on lt.side).

* if connected to ! bronchial tree air containing cystic masses ± air fluid levels

(infection).

Bronchography:

* ?? c.m. rarely enters the lesion.

*Bronchial tree is spread around the mass & is typically complete with no of its

divisions.

Angiography:

* derives its bl. supply from ! descending thoracic aorta.

* venous drainage is via the pulmonary system or IVC.

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II. Extra lobar : The non-functioning portion of the lung (sequestrated portion)

develops enclosed in its own pleura.

It is much less common than intralobar sequestration & is interposed between inferior

surface of lt lower lobe & diaphragm + other congenital anomalies (found at autopsy).

Angiography:

* arterial supply is frequently from abdominal aorta.

* venous drainage is via IVC, azygous or portal venous system.

C/P : Recurrent infection in part of a lung with unusual abscess, cavity or cyst esp

at left lung base.

LUNG ABSCESS (Localized suppurative inflammation of lung)

Types (modes of infection)

1. Inhalation : (primary), commonest, usually in base of Rt lung

Stages

- Pneumonic : patch of consolidation surrounded by congestion.

- Rupture: Central necrosis, communicate with br. tree coughing of liquid

center.

- Acute cavitation : irregular wall & surrounded by excessive inflammatory

reaction, thin shaggy wall.

- Chronic abscess : inner margin smoothens (fibrosis) & surrounding inflammatory

reaction subsides. Thick wall.

2. Pneumonic : complication of pneumonia (met or syn. pneumonic) TB/staph,/ Klebs.

Destruction of affected areas with breaking down & cavitation

3. Embolic (Blood-born):

Part of systemic pyemia or septicemia (staph).

Multiple, small, scattered in both lungs.

4. Extension :

From amebic liver abscess, empyema or mediastinitis (lymphatics).

5. Miscellaneous :

a. Infected hydatid cyst. d. Actinomycosis, candida, Aspergillus)

b. Amoebic lung abscess e. Infected pulmonary infarction.

c. Malignant lung abscess: eccentric, thick irreg wall.

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Complications :

I-Local:

1. Local extension

2. Hemoptysis

3. Fibrosis & bronchiectasis

4. Chronicity amyloidosis.

5. Corpulmonale

II. General:

1. Systemic pyemia septicemia

2. Myocarditis.

3. Toxemia

3. Brain abscess.

4. Moist gangrene.

Radiological features :

I. Abscess arising on cavitation of consolidation :

1. Consolidation : Primary Pn. or Secondary Pn. (br. obst).

2. Site : uncommon above clavicles.

3. Size : Rapid increase indicates air trapping tension cavity.

4. Shape:

- Air fluid level within lumen

- Inner lining : Shaggy smooth

- Wall : thick thin

5. Surrounding lung tissue :

- ↑ markings & patchy consolidation (inflam).

- ↑ lobe containing abscess→ bulging of fissures.

6. Fate : Resolution or lung damage (fibrosis & or bronchiectasis)

II. Abscess on a preexisting abnormality :

- Infected cyst, bronchiectasis, sequestrated segment,

- Hydatid cyst intracavitary body fluid level : water Lilly sign).

- Leak from cyst crumpled float within space originally occupied by

cyst.

- Evidence of the disease may be present elsewhere in the lungs

III. Abscess on a preexisting solid lesion :

1. Peripheral bronchogenic Carcinoma: eccentric cavity with irreg. inner wall.

2. Metastases (sq-cell).

3. Massive fibrosis in pneumoconiosis silicosis, coal miner.

4. Hodgkin node.

5. Wegener’s granuloma.

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6. Caplan nodule.

DD: Lung cavities

1. Infective i.e Abscess

Staph / Klebsiella / TB /Aspiration / Gram-ve / Fungi / Hydatid

2. Neoplastic:

Carcinomas of bronchus / Metastases / Hodgkin

3. Vascular:

Infarction

4. Abnormal lung:

Cystic bronchiectasis / sequestrated segment / bronchogenic cyst

5. Granulomas:

Wegener’s granulomatosis /Rheumatoid nodules caplan / Progressive massive

fibrosis pneumoconiosis / Sarcoidosis.

6. Traumatic

Haematoma / Traumatic lung cyst

Tuberculosis

Body reactions :

I. Proliferative reaction Tubercle made of :

1. Macrophage phagocytose bacilli epithelioid cells.

2. Release of tuberculoprotein (cell mediated immune response) sensitized T-

lymphocytes.

3. Fusion of several epithelioid cells Langhan’s giant cells

* Caseation of tubercle center occurs by lymphokines

4. Lymphocytes & fibroblasts usually surround epitheloid cells.

Fate of tubercle

1. High immunity: complete fibrosis / fibrous capsule & central calcification.

2. Low immunity: fuse to form bigger tuberculous patch / spread (local,

lymphatic, blood. or natural passages).

II. Exudative reaction :

Occurs when T.B bacilli reach the lung, serous membranes & meninges of a

sensitized individual esp. of low resistance, rapid caseation of the lesion occurs.

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Classification of TB:

I. Primary pulmonary TB: Ghon’s.

II. Post primary pulmonary TB: (reactivation or reinfection)

1. Chronic fibrocaseous TB.

2. Acute (Miliary TB of the lung / tuberculous bronchopneumonia)

Post Primary TB :

1. Early fluffy opacities.

2. Chronic active opacities + strands + cavities.

3. Old healed fibrosis + calcification.

Radiological features of Primary Pulmonary TB :

Affects children (& adults exposed for 1st lime)

I. Glandular enlargement: (mediastinal / hilar)

May obstruct bronchi collapse / consolidation.

Disappears completely after healing.

II. Pneumonic consolidation (= pul focus = Gohn’s focus)

Usually single, homogenous, variable in size, in mid or upper zones.

It doesn’t cavitate but caseation is common producing calcified nodule on healing.

III. Small pleural effusion :

Course :

I. Slow resolution leaving only the calcification (no fibrosis in few cases).

II. Spread : Direct, hematogenous or bronchial.

III. Encapsulation & Reactivation.

Radiological features of Post Primary TB: (chronic)

X-ray findings are basically those of consolidation (pneumonia) differentiated from

other pneumonias by :

I. Site : Apical & post. segments of upper lobe & apical segments of lower lobes

(upper post. chest portions)

Commonly bilateral (both apices / one apex & opposite mid zone).

II. Shape of consolidation :

1. Mottling (common): individual shadows 1-5mm in diameter with no tendency

to coalesce.

2. Ill defined roughly circular shadows 0.5-2 cm in diameter.

3. Large homogenous areas up to lobar involvement. It is differentiated from

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other pneumonias by site & infiltration in adjacent lung or other lung.

All these consolidations: Increased Vascular markings reaching them

Evidence of fibrosis

III. Fibrosis: (Lung Damage / may cause fibrothorax):

1. Fibrous strands shift of normal land marks

they persist after clearance of consolidation.

2. Bronchiectasis : upper lobe.

3. Emphysema: localized (bullae) / compensatory (fibrosed or collapsed lobe).

4. Collapse of part or whole of ! lung: sputum block / LN compression / Endo-

bronchial TB.

IV. Cavitation : very common :

- Indicates active disease :

1. Breaking down in an area of homogenous consolidation.

2. A cavity surrounded by aerated lung (2mm thick).

- Usually rounded, seldom contain more than a trace of fluid, usually peripheral &

lung around it invariably shows evidence of infiltration & fibrosis

V. Calcifcation :

In healing lesion irregular calcified foci in clusters.

VI. Combination of events :

Simultaneous spread & healing: areas of infiltration & Cavitation (active disease)

together with fibrosis & calcification (healing).

N.B.: Lymphadenopathy is rare in post primary TB.

Typical radiological features of chronic pulmonary TB :

1. Site: upper post chest positions (DM basal TB)

when bilateral: both apices / one apex & opposite mid zone.

2. Infiltrations : small discrete aceas (1-3mm) / Homogenous shadows (1-3cm).

& Lung damage.

3. Cavitation is common.

4. Calcification in healing parts.

5. Combination of events.

Less common forms of TB :

I. Tuberculoma : (chronic)

- Oval or spherical 1-3 cm in diameter, well defined regular outline

- Usually located near pleural surface, single

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- May calcify (flecks, eccentric).

- May cavitate (eccentric).

- DD : (from neoplasm): calcification / LNS not enlarged / satellite shadows.

II. Massive solid lesions :

Whole lobe (usually UL): dense consolidation - collapse due to bronchial obst .

DD; Bronchogenic.Carcinoma.

II. Segmental lesions

- Collapse consolidation of a single segment (endobronchial TB).

- The commonest causes of segmental lesions in children :

1. TB. 2. FB

Miliary TB : (Hematogenous interstitial nodules.)

- Wide spread mottling evenly distributed in all zones.

- Individual shadows are 1-2mm in diameter with indistinct margins.

- Initially discrete but coalesce into patchy consolidation in the terminal stage.

- No lung changes except those due to the original Illness e.g. evidence of pulm

TB or lymphadenopathy (1ry TB).

DD :

1. Pneumoconiosis . 3. Extrinsic allergic alveolitis

2. Sarcoidosis 4. Haemosiderosis .

Complications :

1. Haemoptysis, suppurative bronchitis.

2. Pleura pleurisy, empyema, pneumothorax.

3. TB heart & ribs Pulmonary hypertension HF.

4. Blood bone, brain, male & female genital

5. TB bronchopneumonia, laryngitis , tongue entritis.

6. Amyloidosis.

Pneumonias with LN enlargement :

1. TB.

2. Viral pneumonia

3. Infections mononucleosis (brucellosis).

?? 2ry to bronchogenic carcinoma