interpretation of basic cxr

CLINICORADIOLOGICAL CONFERENCEDEPTT. OF INTERNAL MEDICINEJ.L.N MEDICAL COLLEGE AJMER

PRESENTOR-DR VIJAY P HAWAGUIDE-DR SANJIV MAHESHWARI

BASICS OF

CHEST X RAY & INTERPRETATION

X-RAY

1895

Wilhelm Röntgen 1845 –1923

X-rays- describe radiation which is part of thespectrum which includes visible light, gamma

rays and cosmic radiation.

Unlike visible light, radiation passes through stuff.

When you shine a beam of X-Ray at a person and put a film on the other side of them a

shadow is produced of the inside of their body.

Different tissues in our body absorb X-rays at different extents:

•Bone- high absorption (white)

•Tissue- somewhere in the middle absorption (grey)

•Fat-dark grey image

•Air- low absorption (black)

Different views of Xray chest•PA•Lateral•AP,decubitis,supine,oblique•Inspiratory-expiratory•Lordotic,apical

PA view•Most frequently requested because:

•Visualization of the lungs excellent•Clear picture of bronchovascular shadow•Radiation risk to the eyes is minimal.

PA view positioning• The patient faces towards the

cassette and the tube is 6 feet away from the patient.

• PA view is better to be taken in full inspiration

• Except for small pneumothorax

Technical aspect•Inspiration•On full inspiration

the diaphragm should lie at the level of 8-10th posterior rib or 5-6th anterior rib.

•Cardiophrenic angle acute

•Lung shadows more black

•Rib spaces increase

Paired inspiratory and expiratory view

Technical aspects•Penetration

Over penetrated (hypertranslucency) Under penetrated(more whitening)

rotation

Rotated x ray

Interpretation of the PA films

1.name,age,sex,date,

side2.trachea3.Heart and

mediastinum4.Diaphragm

6.Pleural spaces7.Lungs8.Hidden areas9.Hila10.Below diaphragm11.Soft tissues12.Bones

DETERMINING RIGHT AND LEFT IN CHEST XRAY•Look for marker•Fundal gas left•Apex of heart left side•Aortic knuckle left•Right diaphragm higher•Left hila at same level or slightly higher

TracheaExamined for • Position• Outline• Should be central, with slight deviation to the right as it

crosses the aortic arch.• Can be pushed away from an abnormal lung affected by

a large pleural effusion, large simple pneumothorax, tension pneumothorax, aortic aneurysm or mediastinal mass.

• The trachea can be pulled towards an abnormal lung affected by extensive collapse, consolidation, pulmonary fibrosis, lobectomy or pneumonectomy.

• Caliber coronal diameter is 25mm for males and 21mm for females

• Para tracheal stripe<5mm• Carina angle:60-75degree.

Heart• Size

• Shape

Transverse cardiac diameter:<14.5cm in

females and <15.5cm in males. An increase of 1.5 cm is significant.

SIZE(A- FROM THE MIDLINE TO MAXIMUM DISTANCE TOWARDS RIGHT,B-FROM MIDLINE TO MAXIMUM DISTANCE

TOWARDS LEFT,C-MAXIMUM ITD,REFERENCE MID LINE FORMED BY JOINING THE SPINOUS PROCESS OF VERTEBRAE)

MEDIASTINUM• RIGHT SUPERIOR

MEDIASTINAL SHADOW FORMED BY SVC AND INNOMINATE VESSELS.

• LEFT SUPERIOR MEDIASTINAL SHADOW FORMED BY THE SUBCLAVIAN ARTERY

• ANT JUNCTION LINE • POST JUNCTION LINE• RIGHT PARATRACHEAL• PARAVERBEBRAL (RT/LT)• AZYGOESOPHAGEAL• AORTOPULMONARY• PARASPINAL LINES 10

MM ON THE LEFT AND 3MM ON THE RIGHT

• THYMUS

Ant and post junction lines• Ant junction line• Parietal and visceral

pleurae meeting anteromedially.oblique course(blue)

• Post juction line.formed by posteromedial surfaces of the pleurae of the upper lobes post to oesophagus(red)

thymus• Triangular sail-shaped

structure, well defined borders projecting from one or both side of the mediastinum.

Para spinal lines

Silhouette Sign*The loss of the normal silhouette of a

structure is called the silhouette sign

*Recognition of this sign is useful in localizing areas of airspace opacities , atelectasis or mass within the lung with the loss of these normal silhouettes on frontal chest radiographs being generally indicative of the site of pathology

1-Right paratracheal stripe : right upper lobe

2-Right heart border : right middle lobe or medial right lower lobe

3-Right hemidiaphragm : right lower lobe

4-Aortic knuckle : left upper lobe5-Left heart border : lingula segments of the left upper lobe

6-Left hemidiaphragm or descending aorta : left lower lobe

Diaphragm• Outline• shape • relative position

Pleural spaces• Costophrenic angles• Cardiophrenic angles

Pleural Fluid :

-It takes about 200-300 ml of fluid before it comes visible on an CXR

-About 5 liters of pleural fluid are present when there is total opacification of the hemithorax

lungs• Local,generalised

abnormality• Comparison of the

translucency• Vascular markings of the

lungs

Zones

LOCAL, GENERALIZED ABNORMALITY

Hidden areas• The apices• Mediastinum and hila• Diaphragm • bones

Hila•Contain the following structures•The inferior pulmonary ligament•The pulmonary vessels•The bronchial vessels•the bronchi•The lymphatic system•The lymph nodes

Right hilum

Left hilum

Below diaphragms

• Gas shadows• Calcifications

 Chilaiditi sign• INCLUDE:

•1)gas between liver

and diaphragm

2)rugal folds within the gas suggesting that it is within the bowel and not free

Soft tissues• Breast shadows and nipple

shadows• Skin folds• Muscles• Companion shadows

Nipple markers

Skin fold

Muscles and companion shadows

bones• Sternum• Clavicles• Scapulae• ribs• spine

Support Devices may be visible like :

a) Endotracheal Tubeb) Nasogastric Tubec) Central Venous Catheterd) Chest Drains

Endotracheal tube

Nasogastric tube:

Lateral film• positioning

Interpretation of lateral film• The clear spaces• Retrosternal space• Retrotracheal space• Vertebral translucency• Diaphragm outline• The fissures• The trachea• The sternum

Retrosternal space

Vertebral translucency

Diaphragm outline• Right diaphragm

continues anteriorly• Left is silhouetted

posteriorly by heart shadow

The fissures

AP view• the patient back is

towards the cassette and tube is 40 inches away from the patient.

• for patients unable to stand

Differentiating from PA view

AP

•Apparent cardiomegaly

•Scapula more prominent

•Ribs appear horizontal

•Clavical appear higher compared to PA view

Decubitus position• The patient faces towards

the cassette while lying in decubitus position and tube Is towards the back

Decubitus position• To asses the volume of

pleural fluid.• Loculated pleural effusion

or mobile• Subpulmonic pleural

effussion

Apical view

Oblique view

• positioning

Oblique view• To visualize retro cardiac

area, the posterior costophrenic angles, the chest wall and the pleural plaques.

• Lordotic PA view

Paired inspiratory and expiratory •Demonstrate air trapping and diaphragm

movements.•Very important in diagnosis of inhaled

foreign body in children.