Small-field-of-view MR angiography of the lower extremity with use of gradient echo techniques

Ten volunteers and 18 patients with angiographically proven vascular disease were studied using 1.5-T superconductive magnet with 10 mT/m gradient capabilities and surface coil. Areas of interest were localized using a 20-30-slice, 200 to 400 tip angle, 50-150-msec repetition time, 5-msec echo time (TE) (FLASH) study, sequentially gated through the cardiac cycle. Subtractions of maximum dephased systolic and diastolic studies produced arteriographic images. Evaluation of arterial structures was facilitated by a small-field-of-view, 20-30-mm anisotropic 3D volume set. Rephasing was facilitated by fast low-angle scans (TE, 10-14msec) with velocity and/or velocity and acceleration gradient compensation schemes. Similar scans with dephasing gradients were obtained and subtracted. These high-resolution, small-field-of-view studies will be discussed and compared with digital subtraction angiograms and film-screen arteriograms