MAGNETIC-RESONANCE TECHNIQUES FOR ASSESSMENT OF MYOCARDIAL VIABILITY

In general, the following three standards for myocardial viability can be used: (a) preserved coronary flow (adequate perfusion); (b) preser ved wall motion (systolic wall thickening); and (c) preserved metaboli sm (metabolic integrity). The current magnetic resonance (MR) techniqu es provide a great potential to measure all three standards of viabili ty. Adequate perfusion can be assessed by spin-echo MR imaging and/or ultrafast MR imaging, systolic wall thickening by cine MR imaging, and the presence of metabolic integrity can be determined by MR spectrosc opy. These noninvasive and versatile techniques have led to an increas ing interest and research in recent years. Particular strengths of the MR techniques are: the inherent three-dimensional data acquisition wi thout radiation exposure; the intrinsic soft-tissue contrast that allo ws tissue characterization; the excellent spatial resolution (in the 1 - to 2-mm range), which permits the evaluation of regional abnormaliti es; multitomographic imaging capabilities that allow acquisition of ca rdiac images in any plane; the inherent sensitivity to blood and wall motion; and the potential for in vivo measurement of myocardial metabo lism using MR spectroscopy. This review article demonstrates that MR t echniques might play a growing role in the assessment of myocardial vi ability.