BACKGROUND:
Cerebral digital subtraction angiography (DSA) has established impaired hemodynamic drainage of intracranial arteriovenous malformations (iAVM) as a risk factor for iAVM hemorrhage. Unlike conventional DSA, MR-DSA offers a noninvasive means of characterizing iAVM hemodynamics. We hypothesize that MR-DSA will demonstrate impaired drainage in iAVMs with history of rupture when compared to iAVMs without history of rupture.
METHODS:
Consecutive patients with untreated, DSA-confirmed iAVM underwent MR-DSA on a 3T Whole-body MR-scanner. For each iAVM, regions of interest (ROI) were drawn on all feeder arteries and draining veins. Time-density curves were constructed for each ROI. The arteriovenous malformation transit time (ATT) was defined for each ROI as the time between contrast arrival and peak intravascular contrast density on the MR time-density curve. The drainage of each iAVM was characterized by the ratio of the draining vein ATT to the mean feeder artery ATT. The ATT ratio was compared between iAVMs with history of hemorrhage and those without. Statistical analysis was performed using a Student’s unpaired t-test with p <0.05 defined as statistically significant.
RESULTS:
From May 2011 to April 2012, 13 patients (7M:6F, 40.6±13.8 years old) were enrolled in our study, with 3 patients presenting with history of hemorrhage and the remainder presenting with history of seizure, focal neurological deficit, headache, or as an incidental finding. The ATT ratio was significantly higher in iAVMs with history of hemorrhage than in those without (1.17±0.06 vs 0.95±0.02, p <2.9E-7).
CONCLUSION:
MR-DSA identifies impaired drainage in iAVMs with history of rupture without exposing patients to the procedural risks and ionizing radiation associated with cerebral DSA.
FIGURE A:
MR-DSA with feeder artery (red) and draining vein (yellow) labeled.
FIGURE B:
Time-density curves of the artery (red) and vein (yellow) from which vessel ATTs were derived.
Angioembolization of Scrotal Arteriovenous Malformations: A Case Report and Literature Review
