Cerebral arteriovenous malformations at 3.0 T: intraindividual comparative study of 4D-MRA in combination with selective arterial spin labeling and digital subtraction angiography.

OBJECTIVE: Prospective intraindividual comparison of 4-dimensional contrast-enhanced MR angiography (4D-MRA) in combination with selective arterial spin labeling (ASL) at 3.0 Tesla and digital subtraction angiography (DSA) for anatomic and functional characterization of cerebral arteriovenous malformations (AVMs).
MATERIALS AND METHODS: In a prospective intraindividual comparative study, 16 patients diagnosed with symptomatic cerebral AVMs underwent 4D-MRA at an isotropic spatial resolution of 1.1 x 1.1 x 1.1 mm and a temporal resolution of 572 milliseconds, regional brain perfusion imaging using selective ASL and DSA. Selective ASL was performed for selective labeling of both carotid arteries and the vertebrobasilar complex. In a stepwise approach, all images were evaluated by 2 radiologists according to technical success rate, Spetzler-Martin classification, identification of arterial feeders, and existence of anatomic variants or functional cross-filling.
RESULTS: 4D-MRA allowed for the same Spetzler-Martin classification as DSA in all patients. Of 28, 26 (93%) feeding arteries were correctly identified by both readers using 4D-MRA alone. Selective ASL provided additional functional or anatomic information in 4 of 16 cases (25%), enabling the detection of a cross-filling feeding artery that was not identified by 4D-MRA without selective ASL, thus improving the sensitivity of MRI in identification of arterial feeders from 26/28 (93%) to 27/28 (96%). The additional functional information regarding anatomic variants and cross-filling provided by selective ASL was confirmed by DSA in all cases.
CONCLUSION: 4D-MRA in combination with selective arterial spin labeling is a promising tool for the noninvasive assessment of cerebral AVMs providing functional information that so far has been gained only with DSA.