Page 14 of 17
RD7.3 | Imaging in Internal Medicine — Practice Quiz
Click any question card to reveal the correct answer.
A 58-year-old man presents 90 minutes after sudden-onset right hemiplegia and global aphasia. He is being assessed for intravenous thrombolysis. Which imaging study must be performed first, and what is its primary purpose?
Correct. Non-contrast CT (NCCT) is the mandatory first-line study in suspected acute stroke. Its overriding purpose is to exclude haemorrhage, because thrombolysis given to a haemorrhagic stroke is catastrophic.
Every patient with suspected acute stroke gets an immediate non-contrast CT brain to exclude haemorrhage before any thrombolytic decision. CT cannot be withheld for a 'cleaner' study.
The first and time-critical question is haemorrhage or not. NCCT answers this immediately and governs whether thrombolysis can proceed; advanced vascular/perfusion imaging follows only after haemorrhage is excluded.
Click to reveal answer
A 62-year-old woman is brought in 1 hour after sudden left-sided weakness. Her non-contrast CT brain shows no haemorrhage and no established hypodensity, but there is a hyperdense right middle cerebral artery. What does this sign indicate?
Correct. A hyperdense MCA represents acute intraluminal thrombus and may be the ONLY CT abnormality in the first 1–2 hours of a large MCA-territory stroke, when the brain parenchyma still looks normal.
The hyperdense MCA sign is acute intraluminal thrombus and is often the earliest (sometimes the only) CT finding in hyperacute large-vessel stroke.
The hyperdense MCA sign reflects fresh thrombus in the vessel lumen. Always check the Sylvian fissure for an asymmetrically dense artery — it can be the earliest and only clue to a large-vessel occlusion.
Click to reveal answer
A 45-year-old woman develops acute pleuritic chest pain and breathlessness 5 days after major orthopaedic surgery. She is haemodynamically stable with normal renal function and no contrast allergy. Pulmonary embolism is strongly suspected. Which is the first-line definitive imaging investigation?
Correct. CTPA is the first-line definitive imaging study for PE in almost every patient. It directly demonstrates intraluminal filling defects and assesses clot burden and right-heart strain.
CTPA is the first-line definitive imaging test for suspected PE; V/Q scanning is the alternative when CTPA is contraindicated or to minimise radiation.
CTPA is first-line for confirming PE. V/Q is reserved for patients in whom CTPA is contraindicated (e.g. severe contrast allergy, renal impairment) or to reduce radiation, such as in pregnancy.
Click to reveal answer
A 30-year-old woman who is 28 weeks pregnant presents with breathlessness and tachycardia. After clinical assessment, definitive imaging for pulmonary embolism is required. Compared with a younger non-pregnant patient, which imaging consideration is most appropriate here?
Correct. In pregnancy, V/Q scanning is a recognised alternative to CTPA, partly to reduce radiation dose to maternal breast tissue. Imaging must not be withheld when PE is suspected, as untreated PE is a leading cause of maternal death.
Pregnancy is a recognised situation in which V/Q scanning is chosen over CTPA to reduce radiation; definitive imaging is never withheld when PE is suspected.
Pregnancy is a key special situation where V/Q is considered as an alternative to CTPA to limit radiation, especially to breast tissue. PE must still be definitively investigated; D-dimer is unreliable and a chest X-ray cannot exclude PE.
Click to reveal answer
A 68-year-old man presents with progressive breathlessness and orthopnoea. His chest radiograph shows an enlarged cardiac silhouette with a cardiothoracic ratio of 0.6, upper-lobe blood diversion, and Kerley B lines. Which is the single most appropriate next imaging investigation to guide long-term management?
Correct. The chest X-ray confirms heart failure (cardiomegaly with CTR >0.5 on a PA film, cephalisation, Kerley B lines). Echocardiography is the next step to measure ejection fraction, which distinguishes HFrEF from HFpEF and directs therapy.
CXR confirms congestion and cardiomegaly (CTR >0.5 on PA film); echocardiography then measures EF (HFrEF <40%) to classify heart failure and direct therapy.
The radiograph already establishes failure. The next study must answer 'what is the ejection fraction?' — echocardiography provides this and classifies the heart failure to guide long-term treatment.
Click to reveal answer
A chest radiograph in a breathless patient is being read as a 'pressure gauge' for rising pulmonary venous pressure. Which sequence best reflects the order in which radiographic signs of heart failure typically appear as pulmonary venous pressure climbs?
Correct. The signs follow a staged sequence mapping onto rising capillary wedge pressure: cardiomegaly and upper-lobe diversion, then interstitial oedema (Kerley B lines), then alveolar (bat-wing) oedema and pleural effusions.
Radiographic heart-failure signs appear in a predictable order with rising pulmonary venous pressure: cardiomegaly/upper-lobe diversion → interstitial (Kerley B) oedema → alveolar (bat-wing) oedema and effusions.
Read the CXR as a pressure gauge: cardiomegaly and cephalisation appear first, then interstitial (Kerley B) changes, and finally alveolar bat-wing oedema with effusions as pressure rises further.
Click to reveal answer
A 50-year-old man with suspected non-alcoholic fatty liver disease is referred for imaging of diffuse liver disease. Which is the appropriate first-line imaging modality, and what is the characteristic finding of hepatic steatosis on it?
Correct. Ultrasound is first-line for diffuse liver disease. Fatty liver shows increased echogenicity, classically seen as loss of the normal hepatorenal contrast — the liver becomes brighter than the adjacent right renal cortex.
Ultrasound is first-line for diffuse liver disease; fatty liver shows increased echogenicity (loss of hepatorenal contrast — liver brighter than right renal cortex).
Ultrasound is the first-line modality. Fatty infiltration increases echogenicity, making the liver brighter than the right kidney (loss of hepatorenal echo contrast). Arterial hyperenhancement with washout is the CT/MRI signature of HCC, not steatosis.
Click to reveal answer
A 60-year-old man with established cirrhosis is on a hepatocellular carcinoma surveillance programme. A 3 cm lesion is found and characterised on multiphasic contrast-enhanced imaging. Which enhancement pattern is most characteristic of hepatocellular carcinoma?
Correct. The classic imaging signature of HCC on multiphasic CT/MRI is arterial-phase hyperenhancement followed by washout in the portal venous/delayed phase, reflecting its predominant arterial blood supply.
HCC on multiphasic CT/MRI shows arterial-phase hyperenhancement with portal venous/delayed-phase washout; surveillance in cirrhosis uses 6-monthly USG ± AFP.
HCC characteristically shows arterial hyperenhancement (it is fed mainly by the hepatic artery) with subsequent washout on portal venous/delayed phases. Progressive peripheral nodular fill-in describes a haemangioma; absent enhancement with water density describes a simple cyst.
Click to reveal answer