1Which chest X-ray (CXR) projection is most commonly preferred for a patient who can stand?
Posteroanterior (PA) projection.
2When is an anteroposterior (AP) chest X-ray usually performed?
When a patient is too unwell or unable to stand for a PA radiograph, often using a portable machine.
3How can an AP chest X-ray differ in appearance from a PA chest X-ray?
The heart may appear magnified, the scapulae may overlap the lung fields, and the clavicles may appear more horizontal.
4What colour does air appear on an X-ray?
Black, because air absorbs very little X-ray radiation.
5What colour do bones and metal appear on an X-ray?
White, because they absorb or attenuate more X-ray radiation.
6What does RIPE stand for when assessing a chest X-ray?
Rotation, Inspiration, Projection, and Exposure.
7What is RIPE used for?
To assess the technical quality of a chest X-ray before interpreting abnormalities.
8How is rotation assessed on a chest X-ray?
The spinous processes should lie midway between the medial ends of the clavicles, with the clavicles approximately symmetrical.
9How many ribs should be visible on an adequately inspired PA chest X-ray?
Approximately 5–7 anterior ribs or 8–10 posterior ribs above the diaphragm.
10How does an underpenetrated chest X-ray appear?
Too white, with insufficient detail visible behind the heart.
11How does an overpenetrated chest X-ray appear?
Too dark, with excessive visibility of structures behind the heart and potentially reduced visibility of lung markings.
12What artefacts or devices should be checked for when interpreting a chest X-ray?
Examples include ECG leads, pacemakers, central venous catheters, nasogastric tubes, and other monitoring or medical devices.
13How does a pulmonary embolism usually appear on a chest X-ray?
The chest X-ray is often normal or shows nonspecific abnormalities; the embolus itself is usually not visible.
14What does ABCDE stand for when systematically interpreting a chest X-ray?
Airway, Breathing, Cardiac, Diaphragm, and Everything else.
15What should be assessed under A — Airway — on a chest X-ray?
Tracheal position and alignment, including any deviation, as well as the main bronchi where visible.
16What pathologies can cause tracheal deviation on a chest X-ray?
Tension pneumothorax, major lung collapse, a large pleural effusion, pneumonectomy, or a large mass. The direction of deviation depends on the cause.
17How does a tension pneumothorax affect tracheal position?
It can push the trachea away from the affected side, particularly when under pressure.
18How does major lung collapse affect tracheal position?
It can pull the trachea towards the affected side due to volume loss.
19How can a large pleural effusion affect tracheal position?
It can push the trachea away from the affected side if sufficiently large.
20How can pneumonectomy affect tracheal position?
It can pull the trachea towards the side of the removed lung due to volume loss.
21What should be assessed under B — Breathing — on a chest X-ray?
Lung fields and markings, consolidation, masses, pneumothorax, pleural effusions, costophrenic angles, and hilar size and appearance.
22What does blunting of the costophrenic angle suggest on a chest X-ray?
Most commonly a pleural effusion, although pleural thickening can also cause blunting.
23What might an enlarged hilum indicate on a chest X-ray?
Hilar lymphadenopathy, a central mass, or enlarged pulmonary vessels.
24What should be assessed under C — Cardiac — on a chest X-ray?
Heart size, cardiac contours, mediastinal width, and the position of the cardiac silhouette.
25How is cardiomegaly assessed on a PA chest X-ray?
The cardiothoracic ratio is greater than 50%, although projection and image quality must be considered.
26Why is cardiomegaly more difficult to assess on an AP chest X-ray?
AP projection magnifies the heart, potentially making it appear enlarged even when its true size is normal.
27What should be assessed under D — Diaphragm — on a chest X-ray?
The position and contour of both hemidiaphragms, their relative heights, and the costophrenic angles; look for free air beneath the diaphragm.
28Which hemidiaphragm is normally higher on a chest X-ray?
The right hemidiaphragm is usually slightly higher than the left.
29What can cause an elevated hemidiaphragm on a chest X-ray?
Phrenic nerve palsy, lung volume loss, diaphragmatic eventration, or subdiaphragmatic causes.
30What should be assessed under E — Everything else — on a chest X-ray?
Bones, soft tissues, visible upper abdomen, medical devices, and other abnormalities not covered by the preceding steps.
31What bony abnormalities should be checked for when interpreting a chest X-ray?
Rib or clavicle fractures, vertebral abnormalities, destructive bone lesions, and other skeletal injuries.