Question:medium
What is the investigation of choice for screening of proximal internal carotid artery stenosis?
What is the investigation of choice for screening of proximal internal carotid artery stenosis?
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Screening favours the non-invasive bedside test that grades flow velocity.
Updated On: Jun 24, 2026
- Doppler flow USG
- CT subtraction angiography
- MRI
- Angiography (DSA)
Show Solution
The Correct Option is A
Solution and Explanation
Step 1: When the goal is to screen a population for narrowing at the carotid origin, the chosen modality must avoid contrast, radiation and invasiveness yet still measure the degree of stenosis.
Step 2: Color Doppler ultrasound meets every one of these needs. The B-mode component shows the plaque and vessel anatomy, and the Doppler component records peak systolic velocity, which climbs as the lumen narrows, allowing the stenosis to be graded accurately and repeatedly at the bedside.
Step 3: The remaining options are confirmatory or definitive rather than screening tools. DSA, the historical gold standard, is invasive with a small stroke risk; CT angiography needs iodinated contrast and radiation; MR angiography is expensive and less accessible. They are used after a positive screen, not for the initial sweep.
Step 4: Therefore Doppler flow USG is the screening investigation of choice.
\[\boxed{\text{Doppler flow USG}}\]
Step 2: Color Doppler ultrasound meets every one of these needs. The B-mode component shows the plaque and vessel anatomy, and the Doppler component records peak systolic velocity, which climbs as the lumen narrows, allowing the stenosis to be graded accurately and repeatedly at the bedside.
Step 3: The remaining options are confirmatory or definitive rather than screening tools. DSA, the historical gold standard, is invasive with a small stroke risk; CT angiography needs iodinated contrast and radiation; MR angiography is expensive and less accessible. They are used after a positive screen, not for the initial sweep.
Step 4: Therefore Doppler flow USG is the screening investigation of choice.
\[\boxed{\text{Doppler flow USG}}\]
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