Chest X-ray (CXR) is the most commonly performed imaging study in radiology. Despite being a basic tool, subtle findings are often missed without a structured review. A systematic approach ensures no abnormality is overlooked.
📌 Step 1: Technical Review (RIPE)
Before interpreting, always check image quality:
- R – Rotation: Medial ends of clavicles equidistant from spinous processes.
- I – Inspiration: At least 6 anterior or 10 posterior ribs visible.
- P – Projection: PA vs AP film. AP magnifies heart size.
- E – Exposure: Vertebral bodies just visible through heart shadow.
📌 Step 2: Airway & Mediastinum
- Trachea: Midline or deviated?
- Carina & bronchi: Sharp angle, obstruction?
- Mediastinum: Widened? Mass? Vascular contour?
📌 Step 3: Breathing (Lungs & Pleura)
- Lung zones: Compare upper, middle, lower zones.
- Look for:
- Consolidation.
- Collapse/atelectasis (volume loss, shift).
- Interstitial markings (fibrosis, edema).
- Nodules or masses.
- Pleura: Effusion (blunting of costophrenic angles), pneumothorax (absence of lung markings, visible pleural line).
📌 Step 4: Circulation (Heart & Great Vessels)
- Heart size: Cardiothoracic ratio > 0.5 (on PA film) = cardiomegaly.
- Borders: Right atrium, left ventricle, left atrial appendage, ascending aorta, pulmonary artery.
- Pulmonary vasculature: Prominence, redistribution, cephalization.
📌 Step 5: Diaphragm
- Right usually higher than left (by <3 cm).
- Look for free subdiaphragmatic air (perforation).
- Blunting of costophrenic and cardiophrenic angles.
📌 Step 6: Everything Else
- Bones: Ribs, clavicles, spine for fractures or lesions.
- Soft tissues: Neck, chest wall, breast shadows.
- Devices: Tubes, lines, pacemakers, prostheses.
⚡ Teaching Pearls
- Use the ABCDE (Airway, Breathing, Circulation, Diaphragm, Everything else) approach every time.
- Always compare with old films for progression or resolution.
- A poor-quality CXR can mimic disease (rotation → apparent mediastinal shift, underexposure → false consolidation).
🗂️ Flowchart: Systematic CXR Approach (ABCDE)
Start with Technical Quality (RIPE):
- Rotation → Clavicles symmetrical
- Inspiration → ≥6 anterior ribs
- Projection → PA vs AP
- Exposure → Spine just visible behind heart
➡️ A – Airway
- Trachea midline?
- Carina visible?
- Mediastinum widened?
➡️ B – Breathing (Lungs & Pleura)
- Compare zones (upper, middle, lower)
- Consolidation, collapse, nodules?
- Pleural effusion or pneumothorax?
➡️ C – Circulation (Heart & Vessels)
- Heart size (CTR < 0.5 on PA)
- Borders well-defined?
- Pulmonary vasculature normal?
➡️ D – Diaphragm
- Right > left (by <3 cm)
- Costophrenic/cardiophrenic angles sharp?
- Free air below diaphragm?
➡️ E – Everything Else
- Bones: ribs, clavicle, spine
- Soft tissues: neck, chest wall, breasts
- Devices: tubes, lines, prostheses
✅ Key takeaway:
Follow RIPE → ABCDE to avoid missing subtle but life-threatening findings.
