Chest X-ray Interpretation Guide: ABCDE Approach for Medi...

Chest X-ray Interpretation Guide: ABCDE Approach for Medical Students Chest X-ray interpretation is a core clinical skill for medical students, interns, clinical officers, nurses and doctors. A systematic approach prevents missed diagnoses and helps you describe findings clearly during ward rounds, exams and emergency care. Before You Start: Check Image Quality Always begin with patient details and film quality before describing pathology. Check What to assess Why it matters Patient details Name, age, date and projection Prevents reporting the wrong film Projection PA, AP, lateral or portable film AP films can exaggerate heart size Rotation Medial clavicles equidistant from spinous processes Rotation can mimic mediastinal shift Inspiration At least 5 to 6 anterior ribs visible above the diaphragm Poor inspiration can mimic basal disease Exposure Vertebrae faintly visible behind the heart Underexposure can hide lung base pathology A: Airway Trace the trachea from the neck into the chest. It should lie centrally or slightly to the right at the aortic arch. Then inspect both main bronchi. Important airway findings include: Tracheal deviation away from pathology, as in a large tension pneumothorax or pleural effusion. Tracheal deviation toward pathology, as in lung collapse or fibrosis. Widening of the carina, which may suggest left atrial enlargement or subcarinal lymphadenopathy. Endotracheal tube position, ideally 3 to 5 cm above the carina. B: Breathing and Lung Fields Compare the two lungs zone by zone from apex to base. Look for symmetry, abnormal opacities, hyperlucency, lung markings and pleural edges. Consolidation on CXR Consolidation occurs when alveoli fill with fluid, pus, blood or cells. It appears as increased white opacity within the lung. Common signs of consolidation: Air bronchograms, where air-filled bronchi are visible against opaque alveoli. Lobar or segmental distribution. Silhouette sign, where a normally visible border is lost. Associated fever, cough, pleuritic pain or raised inflammatory markers. Examples: Right middle lobe consolidation can obscure the right heart border. Left lower lobe consolidation can obscure the left hemidiaphragm. Right lower lobe consolidation can obscure the right hemidiaphragm. Lung Collapse on X-ray Lung collapse, or atelectasis, causes volume loss. Unlike consolidation, collapse pulls structures toward the affected side. Feature Consolidation Collapse Opacity Present Present Volume loss Usually absent Present Mediastinum Usually central Pulled toward affected side Fissures Usually normal Displaced Diaphragm May be obscured May be elevated Signs of collapse include raised hemidiaphragm, crowded ribs, displaced fissures, hilar displacement and mediastinal shift toward the abnormal side. C: Circulation, Cardiac Silhouette and Mediastinum Assess heart size, heart borders, hilar regions and the mediastinum. Cardiothoracic ratio is normally less than 50% on a PA film. It is less reliable on AP portable films because magnification can make the heart appear enlarged. Look for: Cardiomegaly. Pulmonary venous congestion. Upper lobe blood diversion. Kerley B lines. Perihilar bat-wing oedema. Pleural effusions. Widened mediastinum. A widened mediastinum may reflect aortic disease, mediastinal mass, lymphadenopathy or technical factors such as AP projection and rotation. D: Diaphragm and Pleura Inspect both hemidiaphragms and costophrenic angles. Key findings: Blunted costophrenic angle suggests pleural effusion. Flattened diaphragms suggest hyperinflation, often seen in COPD or asthma. Free air under the diaphragm suggests pneumoperitoneum. Raised hemidiaphragm may occur with collapse, phrenic nerve palsy or abdominal pathology. Pleural effusion often produces a meniscus sign and homogeneous basal opacity. A large effusion may push the mediastinum away from the affected side. E: Everything Else Finish by checking bones, soft tissues, devices and review areas. Review areas commonly missed: Lung apices. Behind the heart. Below the diaphragms. Hila. Costophrenic angles. Ribs, clavicles and shoulders. Devices to check include endotracheal tubes, nasogastric tubes, central venous catheters, chest drains, pacemakers and ECG leads. Exam Description Template Use a concise structured format: This is a PA chest radiograph of adequate inspiration and exposure. The trachea is central. There is right lower zone air-space opacity with air bronchograms and loss of the right hemidiaphragm, consistent with right lower lobe consolidation. The heart size is not enlarged. No pleural effusion or pneumothorax is seen. Overall impression: right lower lobe pneumonia. Common Pathology Patterns Condition Typical CXR findings Key clue Pneumonia Focal consolidation, air bronchograms Fever, cough, raised inflammatory markers Pulmonary oedema Cardiomegaly, perihilar shadowing, Kerley B lines Heart failure symptoms Pneumothorax Pleural line with absent lung markings beyond it Sudden pleuritic pain,