Severe stenosis of the internal carotid artery, case 1

Severe stenosis at the origin of the left internal carotid artery, 1.5 T.

This 65 year old female patient complained of repeated episodes of transient aphasia.
Doppler ultrasound was suggestive for occlusion of the left internal carotid artery. The patient was known to be allergic to iodinated contrast media, therefore MRA was elected for further imaging evaluation. It showed severe stenosis at the origin of the internal carotid artery with residual distal flow above.
The information provided by MRA was considered to be adequate to guide subsequent carotid endarterectomy by the vascular surgeon. At operation, an atheromatous plaque and a severe stenosis at the origin of the internal carotid artery were found.

Fig.1 Sagittal 3D TOF MR angiograms in slightly different projections.
These targeted MIP images of left carotid artery exhibit a flow gap (hemodynamically significant stenosis) at the initial segment (arrow), and a faint intravascular signal in the post-stenotic segment of the left internal carotid artery.

Fig.2 The 2D TOF MR angiograms (intravolume spin saturation is less likely to occur, thus slow flow is optimally visualized with this technique) yield better visualization of the poststenotic slow flow (blue arrow) and hence provide, in this case, more accurate delineation of the actual extent of the stenosis at the origin of the left internal carotid artery (yellow arrow).

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