ADVANCED MR-IMAGING TECHNIQUES FOR EVALUATION OF THE HEART AND GREAT-VESSELS

A ''one-stop shop'' for evaluating cardiac disease with magnetic reson ance (MR) imaging is progressing toward clinical reality and promises to have a major effect on the care of patients with cardiac disease. T 1-weighted conventional spin-echo imaging gated to the cardiac cycle y ields good anatomic detail but requires long imaging times and provide s only static images of a single cardiac phase. Fast MR imaging with e lectrocardiographically (ECG) gated, low-flip-angle, segmented k-space gradient-recalled-echo (GRE) sequences provides excellent image quali ty with sufficiently high temporal resolution to ''freeze'' cardiac mo tion. Segmented k-space sequences improve on standard EGG-gated GRE se quences by allowing many cardiac phases, or frames of a cine sequence, to be imaged in a single breath hold with prospective cardiac gating, As commercial implementations of segmented k-space imaging become mor e widely available, the applications of this technique are expanding f rom research protocols to include many clinical applications in the he art and great vessels. Such applications include evaluation of vascula r anatomy (coronary angiography, aortic disease, aberrant vessels, vas cular access), cardiac anatomy (congenital anomalies, right ventricula r dysplasia, constrictive pericarditis, valvular function), myocardial perfusion, and myocardial wall motion.