Question 1

What is chest X-ray interpretation?

Accepted Answer

Chest X-ray (CXR) interpretation is the systematic assessment of a plain chest radiograph to identify normal anatomy and detect abnormalities such as pneumothorax, pleural effusion, consolidation, pulmonary oedema (pulmonary edema), cardiomegaly, and mediastinal pathology. A structured approach — assessing airway, breathing, circulation, diaphragm, and everything else (ABCDE) — helps ensure no findings are missed.

Question 2

How can I practise reading chest X-rays?

Accepted Answer

ThoraSwipe offers free CXR practice using real radiographs sourced from Wikimedia Commons. Each case presents a chest X-ray for you to classify as normal or abnormal, then challenges you to name the diagnosis from a multiple-choice list, and finally reveals annotated findings with a clinical explanation. Spaced repetition and progressive difficulty from easy to expert help build pattern recognition efficiently.

Question 3

What does a normal chest X-ray look like?

Accepted Answer

A normal PA chest X-ray shows a clear trachea midline, symmetric lung fields without opacity or consolidation, a cardiothoracic ratio below 0.5, sharp costophrenic angles, a normal hilum on both sides, and a visible diaphragm outline. Normal variants such as pectoralis muscle shadows or a prominent aortic knuckle can sometimes mimic pathology.

Question 4

How do you identify a pneumothorax on a chest X-ray?

Accepted Answer

A pneumothorax appears as a visible pleural line — a thin white line parallel to the chest wall with absent lung markings beyond it. On an erect PA CXR, the apex is the most common location. A large tension pneumothorax additionally shows tracheal and mediastinal deviation away from the affected side.

Question 5

Who is ThoraSwipe designed for?

Accepted Answer

ThoraSwipe is designed for medical students, junior doctors (foundation and core trainees), radiographers, and any healthcare professional who wants to build or refresh chest X-ray pattern recognition skills. Cases range from easy (classic presentations) to hard (subtle findings requiring clinical context integration), making it suitable for learners at different stages.

Question 6

Is ThoraSwipe free to use?

Accepted Answer

Yes. ThoraSwipe is completely free. No account, login, or subscription is required. It runs entirely in your browser with no data collection.

Question 7

What does a pleural effusion look like on a chest X-ray?

Accepted Answer

A pleural effusion appears as a homogeneous opacity that blunts the costophrenic angle on an erect PA chest X-ray. Small effusions (less than 200–300 mL) may only blunt the lateral costophrenic angle. Larger effusions produce a meniscus sign with a concave upper border and opacify the lower zone. A massive effusion causes complete opacification of the hemithorax with contralateral mediastinal shift. A subpulmonary effusion mimics an elevated hemidiaphragm. ThoraSwipe includes cases of both moderate and massive pleural effusion with annotated findings.

Question 8

What are the chest X-ray signs of pulmonary oedema?

Accepted Answer

Pulmonary oedema on a chest X-ray produces a classic set of signs: upper lobe blood diversion (vessels in the upper zones are larger than lower zone vessels), Kerley B lines (short horizontal interstitial lines at the lung bases from fluid in the interlobular septa), cardiomegaly (cardiothoracic ratio greater than 0.5 on a PA film), bilateral pleural effusions, and alveolar shadowing producing a perihilar bat-wing pattern in severe cases. These findings represent the radiographic spectrum from early interstitial oedema to frank airspace flooding.

Question 9

What is the ABCDE approach to chest X-ray interpretation?

Accepted Answer

The ABCDE approach to chest X-ray interpretation is a systematic method ensuring no finding is missed: A — Airway (trachea central, carina angle, main bronchi patent); B — Breathing (lung fields clear, pleural spaces, diaphragm position); C — Circulation (heart size and borders, hila, mediastinal width); D — Diaphragm (both hemidiaphragms sharp, costophrenic angles clear, subdiaphragmatic gas); E — Everything else (bones, soft tissues, review areas, lines and tubes). A structured approach prevents anchoring on an obvious finding and missing a second abnormality — a common error in high-pressure clinical settings.

Question 10

What does pneumonia look like on a chest X-ray?

Accepted Answer

Pneumonia on a chest X-ray appears as airspace opacification — a white area where air-filled alveoli are replaced by fluid or inflammatory exudate, producing air bronchograms (visible bronchi within the opacity). Lobar pneumonia consolidates an entire lobe with a sharp lobar border. The silhouette sign is the key localising feature: right middle lobe pneumonia obscures the right heart border; lower lobe pneumonia obscures the hemidiaphragm. COVID-19 pneumonia characteristically produces bilateral peripheral ground-glass opacities. ThoraSwipe covers eight pneumonia patterns including lobar consolidation, silhouette sign, COVID-19, necrotising pneumonia, and PCP.

Question 11

What does CXR stand for?

Accepted Answer

CXR stands for chest X-ray (also written chest xray). It refers to a plain-film radiograph of the thorax used to assess the lungs, heart, mediastinum, pleura, and bony thorax. CXR is the standard abbreviation used in clinical notes, referral letters, and radiology reports worldwide.

Question 12

How do I learn to read chest X-rays as a medical student?

Accepted Answer

Learning chest X-ray interpretation as a medical student requires three things: a systematic approach (such as ABCDE), pattern recognition through repeated exposure to real radiographs, and immediate feedback to correct misconceptions. ThoraSwipe is designed for exactly this — each case requires you to first commit to a normal or abnormal decision, then name the specific diagnosis from a multiple-choice list, before revealing annotated colour-coded findings and a full clinical explanation. Regular practice of 15–20 minutes per session covering both normal and pathological films is more effective than occasional longer sessions. Starting with easy classic cases and progressing to subtle hard cases builds a reliable mental library of CXR patterns.

Question 13

What does cardiomegaly look like on a chest X-ray?

Accepted Answer

Cardiomegaly is defined as a cardiothoracic ratio (CTR) greater than 0.5 on a PA chest radiograph — the transverse cardiac diameter exceeds half the maximum transverse thoracic diameter. The heart appears globally enlarged, or specific chamber changes are visible: left ventricular enlargement displaces the cardiac apex downward and to the left; right heart enlargement rounds the right heart border; left atrial enlargement splays the carina and creates a double density behind the right heart border. CTR cannot be reliably assessed on AP (portable) films due to cardiac magnification. Common causes include dilated cardiomyopathy, hypertensive heart disease, and valvular disease. Pericardial effusion produces a globular water bottle cardiac silhouette with clear lung fields — distinct from the pulmonary venous congestion typically seen in cardiac failure.

Question 14

What is the silhouette sign in radiology?

Accepted Answer

The silhouette sign describes the loss of a normally visible border when two adjacent structures share the same radiographic density. On a chest X-ray, it localises consolidation or collapse to a specific lobe: right middle lobe disease obliterates the right heart border; lower lobe consolidation obliterates the ipsilateral hemidiaphragm; lingular consolidation obliterates the left heart border. Two structures that are both soft-tissue density cannot be distinguished from one another — their shared border disappears. A preserved border is equally informative: a right lower lobe opacity that leaves the right heart border intact confirms the right middle lobe is clear. ThoraSwipe includes dedicated silhouette sign cases for right middle lobe and right lower lobe pneumonia.

Question 15

What does TB look like on a chest X-ray?

Accepted Answer

Tuberculosis (TB) produces different chest X-ray appearances depending on stage and immune status. Primary TB may appear normal or show a small peripheral Ghon focus with ipsilateral hilar lymphadenopathy (Ghon complex). Post-primary (reactivation) TB classically involves the upper lobes and apical segments of the lower lobes, producing nodular opacities and cavitation — sometimes with an air-fluid level. Miliary TB produces innumerable 1–3 mm micronodules distributed randomly throughout both lungs. Old TB sequelae appear as bilateral apical pleural thickening, fibrotic scarring, and calcified nodules or lymph nodes. Any upper lobe cavitating lesion on CXR should prompt consideration of TB. ThoraSwipe covers miliary TB, active cavitary TB, and old TB sequelae across three separate cases.

Question 16

How do you identify a pleural effusion on CXR?

Accepted Answer

To identify a pleural effusion on a chest X-ray, start at the costophrenic angles: blunting of the lateral costophrenic angle on an erect PA film indicates at least 200–300 mL of fluid. A meniscus sign — a concave upper border sweeping up laterally — confirms free fluid. Larger effusions obscure the hemidiaphragm outline and produce a D-shaped opacity over the lower zone. On a supine film (common in ICU), fluid layers posteriorly, causing diffuse haziness over the affected hemithorax without a meniscus sign. Massive effusions opacify the entire hemithorax and shift the mediastinum contralaterally. A subpulmonary effusion mimics an elevated hemidiaphragm — ultrasound or lateral decubitus film confirms the diagnosis. Always check both sides, as bilateral effusions are common in cardiac failure and hypoalbuminaemia.

Question 17

What is Hampton's Hump?

Accepted Answer

Hampton's Hump is a peripheral wedge-shaped opacity on a chest X-ray, with its flat base abutting the pleural surface, representing haemorrhagic pulmonary infarction from a pulmonary embolism. It is most commonly seen in the lower lobes and is highly characteristic of pulmonary infarction — though not exclusive to it. Critically, Hampton's Hump is present in only a minority of pulmonary embolism cases — most PEs produce a normal or near-normal CXR. A normal chest X-ray in a patient with acute dyspnoea, pleuritic chest pain, and hypoxia should increase, not decrease, clinical suspicion for PE. The Westermark sign (relative oligaemia distal to the embolus) and a small pleural effusion may accompany the hump. CT pulmonary angiography (CTPA) is the definitive investigation. ThoraSwipe includes a Hampton's Hump case in its pulmonary vascular disease section.

Round Complete

Key Radiographic Findings

Free Chest X-Ray Interpretation Quiz — CXR Practice for Medical Students, Junior Doctors & Radiographers

Round Complete

Key Radiographic Findings