How to Prepare Radiology for FMGE 2026: High-Yield Topics and Strategy

By Dr. Utsav Bhattacherjee, MBBS, MBA · 26 August 2026 · 9 min read

FMGE Radiology high yield topics

• Classic chest X-ray signs — a compact list of named findings, each pointing to a specific diagnosis.
• Imaging modality selection — when X-ray, CT, MRI or ultrasound is the appropriate first choice.
• Common CT and MRI patterns — recognising a handful of frequently tested cross-sectional findings.
• Contrast use and safety — when contrast is indicated and its key contraindications.

Classic chest X-ray signs worth memorising

The silhouette sign is worth understanding mechanistically, not just recognising by name: a normal chest X-ray border exists because two structures of different density sit adjacent to each other. When a lesion of similar density to one of them (such as consolidated lung tissue) replaces the air-filled lung against that border, the border disappears — not because anything moved, but because the density contrast that created the visible line is gone. This is exactly why the silhouette sign can localise disease to a specific lobe without needing an additional view.

Westermark sign vs Hampton’s hump: two sides of the same process

Both point toward pulmonary embolism, but they represent genuinely different things worth distinguishing. Westermark sign reflects reduced blood flow distal to the clot — the vessel is blocked, so the affected lung field appears relatively lucent (darker) from reduced perfusion. Hampton’s hump is the actual infarcted lung tissue itself, once the blocked supply has caused localised tissue death — a wedge-shaped opacity, typically pleural-based. A patient can show either finding, both, or neither, since PE remains fundamentally a clinical and CT-angiography diagnosis, with these plain film signs serving as supportive clues rather than definitive proof.

Choosing the right imaging modality

This is arguably the most practically useful skill in the entire subject, since it applies constantly regardless of which specific condition is being evaluated:

• X-ray — first-line for suspected fractures, pneumonia, and initial chest or abdominal evaluation; fast, low-cost, low radiation, but limited soft tissue detail.
• CT — excellent for detailed cross-sectional anatomy, trauma evaluation and detecting acute hemorrhage; higher radiation dose than X-ray, and often requires contrast for full diagnostic value in many indications.
• MRI — superior soft tissue contrast, the modality of choice for most brain, spine and joint pathology; no ionising radiation, but slower, costlier, and contraindicated with certain implanted metal devices.
• Ultrasound — real-time imaging without radiation, ideal for pregnancy-related imaging, gallbladder and biliary pathology, and rapid bedside assessment (such as the FAST exam in trauma); operator-dependent and limited by bowel gas or body habitus in certain views.

Recognising which modality a clinical scenario is pointing toward — based on the suspected pathology, urgency and patient factors like pregnancy or renal function — is exactly the applied skill this topic tests, more than memorising imaging findings in isolation.

CT findings worth recognising on sight

A handful of CT patterns recur across neurology and trauma questions specifically because they carry immediate management implications. An epidural hematoma classically appears as a biconvex (lens-shaped) hyperdense collection, typically not crossing suture lines, since it is confined by the skull’s suture attachments — often from arterial bleeding (classically the middle meningeal artery) and capable of rapid deterioration. A subdural hematoma classically appears as a crescent-shaped hyperdense collection that can cross suture lines, typically from venous bleeding (bridging veins), and often has a more gradual clinical course, particularly in the elderly or in chronic subdural hematomas. Recognising the shape distinction — biconvex versus crescent-shaped — is frequently the fastest route to the correct diagnosis in an imaging-based vignette, since it reflects the actual anatomical constraint each bleed type is subject to.

Contrast use: indications and key contraindications

Contrast enhances the visibility of blood vessels, tumors and inflammatory processes, but it is not universally appropriate. Iodinated contrast (used with CT) carries a risk of contrast-induced nephropathy, particularly in patients with pre-existing renal impairment, and requires caution or alternative approaches in that population. Gadolinium contrast (used with MRI) carries a risk of nephrogenic systemic fibrosis in patients with significant renal impairment, which is why renal function is checked before gadolinium administration in at-risk patients. Both contrast types carry some allergic reaction risk, though gadolinium reactions are generally less frequent than iodinated contrast reactions. Recognising when a question is testing a contrast safety concern — rather than the underlying pathology itself — is worth watching for specifically, since it is a distinct category of question from pure image interpretation.

Abdominal imaging: free air and bowel patterns

Free air under the diaphragm on an erect chest or abdominal X-ray is one of the most clinically urgent findings in abdominal imaging, indicating a perforated hollow viscus — a surgical emergency requiring prompt recognition rather than delayed confirmation. Bowel obstruction shows a characteristic pattern of dilated bowel loops with air-fluid levels on an erect film, and distinguishing small bowel from large bowel obstruction matters for management: small bowel loops typically show valvulae conniventes (thin, complete folds crossing the full width of the bowel), while large bowel shows haustra (thicker, incomplete folds that do not cross the full width) — a distinction that helps localise the level of obstruction from the imaging pattern alone.

Describing fractures: the vocabulary that matters

Precisely describing a fracture on imaging is not just terminology for its own sake — it directly communicates information relevant to management. Key descriptive elements include the fracture pattern (transverse, oblique, spiral or comminuted, meaning broken into multiple fragments), displacement (whether the fragments have shifted from normal alignment), and angulation (the direction and degree the distal fragment deviates from normal axis). A spiral fracture pattern, for instance, suggests a rotational mechanism of injury, which can itself be a clinically relevant detail — an unexplained spiral fracture in a young child, for example, raises consideration of non-accidental injury, since the mechanism does not match typical accidental trauma patterns at that age. Comminuted fractures generally indicate a higher-energy mechanism than a simple transverse fracture, which can inform both management planning and, in some contexts, the broader clinical picture of how an injury occurred.

A smart study plan for FMGE Radiology

• Build a personal reference table of named chest X-ray signs — they are a compact, defined list that pays off across Medicine and Surgery questions as much as Radiology itself.
• Practise the modality-selection logic actively, using real clinical scenarios, since that is a more transferable skill than memorising findings for any single modality in isolation.
• Learn the epidural-versus-subdural hematoma shape distinction cold — it is one of the fastest, most reliable diagnostic shortcuts in cross-sectional imaging.
• Treat contrast safety as its own testable category, distinct from image interpretation itself, since questions sometimes test the safety consideration rather than the underlying diagnosis.

For the complete high-yield picture across every FMGE subject, see our FMGE high yield topics guide, and for how Radiology fits into your overall timeline, our FMGE December 2026 preparation strategy covers the sequencing across subjects.