Contrast Enhancement of Intracranial Aneurysms on 3T 3D Black-Blood MRI and Its Relationship to Aneurysm Recurrence following Endovascular Treatment

BACKGROUND AND PURPOSE: Endovascular treatment of intracranial aneurysms aims at preventing aneurysm rupture. Contrast-enhanced black-blood MR imaging facilitates imaging of the vessel walls and the aneurysmal sac contents and is therefore suitable for studying the healing process. This study aims to describe imaging findings of aneurysmal contrast enhancement following endovascular treatment and its correlation to recurrence and elapsed time since coiling.

MATERIALS AND METHODS: Patients undergoing MR imaging follow-up after endovascular treatment of an intracranial aneurysm were included. Contrast-enhanced black-blood T1WI was acquired. Aneurysm wall and intra-aneurysmal enhancement were independently assessed by 2 neuroradiologists and were related to the time elapsed since coiling and the presence of recurrence.

RESULTS: Thirty aneurysms in 30 patients were included. The median time elapsed since treatment was 417 days (interquartile range, 189–1273 days). Aneurysmal contrast enhancement was seen in 24/30 (80%) aneurysms. Enhancement inside the sac in 55% (n = 17), the wall in 23% (n = 7), at the dome (n = 1), or at the base (n = 6) was observed. No statistically significant correlation between aneurysmal contrast enhancement and the elapsed time (P = .83) and presence of a recurrence (P = .184) was detected. In 28/30 patients, the images were of adequate diagnostic quality. Stent implants caused negligible image artifacts.

CONCLUSIONS: Intra-aneurysmal contrast enhancement following endovascular treatment of intracranial aneurysms is a common finding and likely reflects the healing process. A long-term study to examine changes occurring with time and their association with packing density, type of coils (bare platinum versus bioactive coils), and aneurysm recurrence is underway (German Clinical Trials Register, DRKS-ID: DRKS00014644).