Table 3.

Yield of neuroimaging: For the purposes of this analysis, imaging was operationally defined as ”positive” if there were clinically relevant findings such as ischemic stroke, carotid artery stenosis, or tumor.

Imaging modality	Pre-intervention	Post-intervention	P value
Head CT positive	3/89 (3%)	4/89 (4%)	0.99
Brain MRI positive	33/109 (30%)	29/131 (22%)	0.18
Neck CTA positive	21/40 (53%)	10/33 (30%)	0.063
Neck MRA positive	12/79 (15%)	6/108 (6%)	0.042
Carotid US positive	7/15 (47%)	5/15 (33%)	0.71

CT, computed tomography, CTA, computed tomography angiography; MRI, magnetic resonance imaging; MRA, magnetic resonance angiography; US, ultrasound.