Background and Purpose--Spontaneous recanalization of an acutely occluded internal carotid artery (ICA) is an important phenomenon, the natural history and incidence of which have been incompletely studied. Although conventional catheter arteriography remains the gold standard for distinguishing total arterial occlusion from hairline residual lumen, CT angiography (CTA) is able to make this distinction noninvasively and more sensitively than either unenhanced MR angiography or ultrasound. The purpose of this report is to raise awareness of spontaneous recanalization and to demonstrate the possible use of CTA in following up cases of ICA occlusion.

Methods--We describe here 2 cases of acute cervical ICA occlusion seen on CTAs done at our institution.

Results--Follow-up CTAs in both cases showed spontaneous recanalization of the ICA requiring ipsilateral carotid endarterectomy within 1 month of the initial presentation.

Conclusions--CTA, an accurate, rapid, and less invasive modality than conventional catheter arteriography, can be used to serially monitor anticoagulated patients with new-onset ICA occlusion for potential spontaneous vascular recanalization. The ability to conveniently assess ICA patency not only may influence management of individual patients but also could help us better establish the true incidence of spontaneous carotid recanalization in future studies.