Stroke Imaging & Diagnostics Flashcards
7 cards from real ASC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Stroke Imaging & Diagnostics flashcards as text
Which CT angiography finding indicates tandem occlusion, a configuration that generally predicts worse outcomes and influences endovascular strategy?
Answer: Ipsilateral cervical ICA occlusion combined with intracranial vessel occlusion
Tandem occlusion describes ipsilateral cervical ICA occlusion combined with intracranial occlusion, requiring a dual treatment strategy and associated with worse reperfusion rates.
On echocardiography performed for stroke workup, which finding is a high-risk cardiac source of embolism requiring anticoagulation?
Answer: Left atrial thrombus
Left atrial thrombus is a definitive high-risk cardioembolic source mandating anticoagulation therapy to prevent recurrent thromboembolic stroke.
When performing carotid duplex ultrasonography, an ICA peak systolic velocity (PSV) greater than 230 cm/s correlates with approximately what degree of stenosis?
Answer: Greater than 70% stenosis
A PSV greater than 230 cm/s in the ICA is the velocity threshold that correlates with greater than 70% stenosis by NASCET criteria in most validated duplex protocols.
A patient with large vessel occlusion stroke has a CT perfusion mismatch ratio of 1.8 with a core of 25 mL. According to major trial criteria (DEFUSE-3, DAWN), is this patient likely eligible for thrombectomy beyond 6 hours?
Answer: Yes, a mismatch ratio ≥1.2 with a core ≤70 mL meets DEFUSE-3 eligibility criteria
DEFUSE-3 required a mismatch ratio ≥1.2, mismatch volume ≥15 mL, and core ≤70 mL; a 25 mL core with a 1.8 ratio meets these criteria, supporting eligibility.
Which vascular imaging finding on CTA most reliably differentiates arterial dissection from atherosclerotic stenosis in a young stroke patient?
Answer: Intimal flap or double lumen sign
An intimal flap or double lumen sign on CTA is pathognomonic for arterial dissection, distinguishing it from atherosclerotic disease which lacks a separating flap.
What is the significance of identifying a 'hypointense MCA sign' on T2*-weighted gradient echo MRI?
Answer: It confirms acute thrombus in the MCA due to susceptibility effect of deoxyhemoglobin
The hypointense MCA sign on GRE T2* reflects the paramagnetic susceptibility of deoxyhemoglobin within fresh thrombus, confirming acute MCA occlusion.
In digital subtraction angiography (DSA) for acute stroke, which grading scale assesses post-thrombectomy reperfusion success?
Answer: eTICI (expanded Thrombolysis in Cerebral Infarction) scale
The eTICI scale grades post-intervention reperfusion on DSA from 0 (no perfusion) to 3 (complete reperfusion), with eTICI 2b-3 considered successful reperfusion.