PHASE-CONTRAST MAGNETIC-RESONANCE OF THE SPINAL-CORD PRELIMINARY-RESULTS IN SPINAL-CORD ARTERIOVENOUS-MALFORMATIONS

In spite of the recent advances in neuroradiology including the CT sca n and the spin-echo-magnetic resonance (MR), accurate diagnosis of art eriovenous malformations (AVMs) involving the spinal cord is still bas ed on selective angiography. This last procedure is invasive and needs to be repeated during the follow up. Phase contrast angio MR was perf ormed with a 0.5 Tesla unit on 12 patients with an AVM involving the s pinal cord (7 intramedullary AVMs, 4 perimedullary fistulas, and 1 dur al fistula with perimedullary venous drainage); 4 of these were invest igated before and after treatment. Angio MR showed abnormal vascular p atterns within the spinal canal in all cases, without distinguishing b etween arteries and veins; the nidus of the intramedullary AVMs was di splayed in all cases. Angio MR provided images of the whole AVMs compa rable to the angiographic pictures, in contrast to the spin-echo MR, w hich provided only discontinued images of the vessels. The efficient r ange of velocity providing images varied, according to the type of the malformation (slow for dural fistulas, rapid for intra-medullary AVMs ). In the 4 patients investigated after treatment, comparison of the i mages obtained before and after treatment permitted assessment of the degree of occlusion of the malformation. Finally, angio MR as a comple ment of spin-echo MR can now be used as a reliable tool for detection of spinal cord AVMs, assessing the indication for angiography, and, fu rthermore, it can probably replace most of the postoperative control a ngiographies. The value of the efficient imaging velocity is disputabl e but seems to depend on the haemodynamic characteristics of the malfo rmation and may then serve as a guide to angiography.