Internal carotid artery occlusion

Proximal occlusion of the left internal carotid artery, 1.5 T.

Fig.1 Transverse source images from a 3D TOF MRA acquisition. The common carotid artery is well visualized (red arrow), however, at a higher level (above the bifurcation) only the external carotid artery (yellow arrow) is seen on the left side, suggesting occlusion.

Fig.2 The transverse MIP reconstruction of the intracranial arteries from a 3D TOF MRA data set (above) demonstrates flow in the intracranial left internal carotid artery bifurcation as well as in the left anterior and middle cerebral arteries. The same MRA acquisition with a presaturation slab positioned on the contralateral carotid siphon and basilar artery results in disappearance of intravascular signal in the left anterior and middle cerebral arteries (below). This confirms the occlusion of the left internal carotid artery and suggests collateral flow (by cross filling through the anterior and posterior communicating arteries).

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