Relative Hypodense Vertebral Artery Sign on Computerized Tomography in Atherosclerotic Near Occlusion

Figure 1

Seven months before presentation left VA is patent with intraluminal average Hounsfield units (aHU) of 60.6 on native CT (open black arrow) (a). 23 hours after symptom onset. Black arrow shows subtle hypodensity with aHU of 42.4 in the left VA (closed white arrow) (b). Three days after symptom onset susceptibility weighted effect in left VA (empty white arrow) (c) and flow void with rest-flow around clot in contrast-enhanced MR T1 (open white arrowhead) (d). MR time-of-flight angiography showing the absence of flow in both VAs (e).

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(b)

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(d)

(e)