Feasibility of high-resolution MR imaging for the diagnosis of intracranial vertebrobasilar artery dissection.

Abstract

OBJECTIVES: To evaluate the feasibility of high-resolution MRI (HR-MRI) for

diagnosing intracranial vertebrobasilar artery dissection (VBD) and to identify

the most useful imaging findings suggesting dissection. METHODS: We

retrospectively reviewed 50 patients with suspected intracranial VBDs who

underwent HR-MRI. Two neuroradiologists independently reviewed the HR-MR images.

The diagnosis based on HR-MRI was compared with the final diagnosis by consensus

among the neuroradiologists, neurointerventionist, and neurologist. Two

neuroradiologists also sought signs of dissection (mural hematoma, dissection

flap, outer-diameter enlargement on T2WI of steno-occlusive lesions). Inter- and

intraobserver agreements were analysed. RESULTS: HR-MRI corroborated the final

diagnosis in 47 (94%; 31 VBD and 16 non-VBD) patients. A mural haematoma was best

detected on T1WI and contrast-enhanced (CE)-T1WI (54.3%). Dissection flaps were

observed in almost all cases on CE-T1WI (91.4 %), and then were detected on T2WI

(68.6%). Outer-diameter enlargement of the steno-occlusive lesions on angiography

was detected in more than half of the cases (62.9%). The two reviewers showed

almost perfect agreement for the diagnosis of VBD and detecting dissection signs

on every sequence. CONCLUSIONS: HR-MRI can be a useful and non-invasive

diagnostic tool for intracranial VBD, and dissection flaps on CE-T1WI are the

signs with the greatest diagnostic value. KEY POINTS: Direct imaging findings of

dissection were well visualised by HR-MRI. Detection of a dissection flap on

CE-T1WI is the most reliable diagnostic finding. HR-MRI could be a useful

diagnostic tool for intracranial VBDs.