interpretation of basic cxr
TRANSCRIPT
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.