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Suspected lower-limb deep vein thrombosis — MRCEM SBA MCQ

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EasyProcedures, imaging and diagnosticsSuspected lower-limb deep vein thrombosisMRCEM SBA

A 54-year-old man attends the emergency department with two days of unilateral calf swelling and tenderness. His two-level DVT Wells score is 2. He has no chest pain or breathlessness. Because proximal leg vein ultrasound was delayed, he received interim therapeutic anticoagulation. The scan is now reported as negative, but his D-dimer is positive. He takes no long-term anticoagulant and is clinically well enough for outpatient follow-up. What is the most appropriate next diagnostic and treatment plan?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: E — Stop interim anticoagulation; repeat proximal ultrasound in 6–8 days.

The negative *proximal* ultrasound does not complete this patient’s diagnostic pathway: his D-dimer is positive, so a repeat proximal leg vein ultrasound is needed in 6–8 days. NICE advises stopping interim therapeutic anticoagulation while arranging that repeat scan. He has no separate indication for ongoing anticoagulation. ([nice.org.uk](https://www.nice.org.uk/guidance/NG158/chapter/recommendations)) A recognises the need for another scan but schedules it too early for the recommended serial-imaging pathway; a scan within 24 hours is relevant when the *initial* scan cannot be obtained promptly. B uses the correct repeat-scan interval but unnecessarily continues interim therapeutic anticoagulation after a negative initial scan. C combines both errors. D treats the negative scan as sufficient despite the positive D-dimer; no repeat imaging would be appropriate under the corresponding NICE pathway if the D-dimer were negative. The decision therefore depends on interpreting the two test results together and distinguishing anticoagulation given while awaiting initial imaging from treatment after that imaging is negative. ([nice.org.uk](https://www.nice.org.uk/guidance/NG158/chapter/recommendations))

Reference: NICE NG158: Venous thromboembolic diseases — recommendations 1.1.3–1.1.4 (2 August 2023) — https://www.nice.org.uk/guidance/NG158/chapter/recommendations NICE NG158: Venous thromboembolic diseases — recommendation 1.1.6 (2 August 2023) — https://www.nice.org.uk/guidance/NG158/chapter/recommendations