ABCDE: Airway, Breathing, Circulation, Diaphragm, Everything else
Expansion
Quality first, using RIPE: Rotation (spinous process midway between the clavicular heads), Inspiration (5 to 7 anterior ribs, or 9 to 10 posterior), Projection (PA or AP, and AP magnifies the heart), Exposure (vertebrae just visible behind the heart).
Then ABCDE:
- A - Airway: trachea central, carina, bronchi, and any deviation
- B - Breathing: lung fields compared zone by zone, pleura, pneumothorax, effusion, consolidation, nodules
- C - Circulation: heart size (cardiothoracic ratio under 50 per cent on a PA film only), heart borders, aortic contour, hila
- D - Diaphragm: right usually higher than left, costophrenic angles, and free air beneath the diaphragm
- E - Everything else: bones, soft tissues, breast shadows, surgical emphysema, and all lines, tubes and devices
The silhouette sign: loss of a normal border localises the pathology to the adjacent structure, since two structures of the same density in contact lose their interface.
| Border lost | Location |
|---|---|
| Right heart border | Right middle lobe |
| Left heart border | Lingula |
| Right hemidiaphragm | Right lower lobe |
| Left hemidiaphragm | Left lower lobe |
| Aortic knuckle | Left upper lobe |
Review areas, checked deliberately because they hide findings: the apices, behind the heart, the hila, below the diaphragm, the costophrenic angles, the bones and the soft tissues.
Always compare with a previous film, which changes the interpretation more often than any individual sign.