Time-resolved spinal MR angiography: initial clinical experience in the evaluation of spinal arteriovenous shunts.
OBJECTIVE
Spinal arteriovenous shunts usually require digital subtraction angiography (DSA) for evaluation. We report a unique time-resolved spinal MR angiographic (TRSMRA) technique with a temporal resolution of 3-6 seconds and spatial resolution of approximately 1 mm(3) that has the potential to noninvasively detect, localize, and follow-up these cases.


METHODS
Eleven patients with clinical presentation and/or MR findings suspicious for a spinal arteriovenous shunt were referred for TRSMRA. Patients subsequently underwent spinal DSA to confirm the presence or absence of a shunt or were followed clinically until an alternative diagnosis was found. TRSMRA was also used to predict the level of the shunt in the positive cases. In addition, 2 of these patients as well as a 12th patient referred to us posttreatment received a follow-up TRSMRA to assess treatment outcome.


RESULTS
Early venous shunting was identified by using TRSMRA in 6 cases. All 6 were confirmed to have an AV shunt on subsequent spinal DSA. The shunt level predicted by TRSMRA consistently correlated with DSA to within 1 vertebral level. In the 5 patients with a negative screening TRSMRA, DSA or clinical outcome confirmed the absence of an arteriovenous shunt in all of the cases. Posttreatment TRSMRA in 3 patients accurately assessed the success or failure of treatment.


CONCLUSIONS
Combining acceleration techniques to achieve high frame rate TRSMRA provides sufficient temporal and spatial resolution to identify, localize, and follow patients suspected of having a spinal arteriovenous shunt. Further study in a larger population is warranted to assess the accuracy of this technique.
Ali
S
S
Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. saad-ali@northwestern.edu
Cashen
T A
TA
Carroll
T J
TJ
McComb
E
E
Muzaffar
M
M
Shaibani
A
A
Walker
M T
MT
D000328:Adult; D000368:Aged; D001164:Arteriovenous Fistula / Q000175:diagnosis*; D020785:Central Nervous System Vascular Malformations / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D013116:Spinal Cord / Q000098:blood supply* / Q000473:pathology*