Contrast-enhanced time-resolved MR angiography of spinal vascular malformations

Purpose: The purpose of this work was to assess the potential and limitatio ns of a contrast-enhanced time-resolved MR angiography technique for evalua tion of spinal vascular malformations. Method: Two patients with intramedullary arteriovenous (AV) malformations a nd three patients with dural AV fistula underwent four serial acquisitions, every 17-20 s, of 20-32 coronal 1.5- to a-mm-thick partitions with a fast 3D SPGR sequence after injection of 0.2-0.3 mmol/kg paramagnetic contrast a gent. This was followed by coronal 3D and sagittal or coronal 2D phase cont rast (PC) MR angiography. Results: No spinal vessels were visualized in the first (baseline) series. In patients with intramedullary AV malformations, the arterial feeders, nid us, and perimedullary draining veins were visualized in the second (early) series. In the third (intermediate) series, the arterial feeder vanished, w hereas the intercostal and lumbar veins appeared. In patients with dural AV fistula, abnormal intraspinal vessel appeared in the third series and pers isted, although less conspicuous, in the fourth (late) series. Contrast-enh anced time-resolved MR angiography demonstrated the venous components of th e lesion with better conspicuity than 3D PC MR angiography, whereas it was inferior for visualization of arterial feeders. Moreover, indirect identifi cation of the level of the dural AV fistula was possible only on the phase display of the 2D PC MR angiography. Conclusion: Contrast-enhanced time-resolved MR angiography is a useful comp lement to PC MR angiography for the evaluation of spinal vascular malformat ion.