MR angiography for the long-term follow-up of dissecting aneurysms of the extracranial internal carotid artery.

Objective: We used MR angiography to examine and follow up the changes of dissecting aneurysms of the extracranial internal carotid artery (ICA).
Materials and Methods: We retrospectively reviewed the records of 101 consecutive patients with dissecting aneurysms of the extracranial ICA. Twenty patients with 26 spontaneous dissecting aneurysms were followed up with MR angiography every 1-2 years (men, 16; women, four; age range, 28-67 years; mean age, 51 years).
Results: The mean duration of follow-up was 41 months (range, 10-93 months). At MR angiography follow-up, 20 aneurysms did not change, four decreased from their original size by 33-53% (mean, 43%), and two resolved. One patient had an asymptomatic recurrent dissecting aneurysm of the extracranial ICA. Clinically, no patient had a thromboembolic stroke or transient ischemic attack during the follow-up period.
Conclusion: MR angiography revealed that dissecting aneurysms of the extracranial ICA remain stable, decrease in size, or resolve--but they do not increase in size.