QUANTITATIVE CARDIAC PERFUSION - A NONINVASIVE SPIN-LABELING METHOD THAT EXPLOITS CORONARY VESSEL GEOMETRY

PURPOSE: To quantitate myocardial arterial perfusion with a noninvasiv e magnetic resonance (MR) imaging technique that exploits the geometry of coronary vessel anatomy. MATERIALS AND METHODS: MR imaging-was per formed with a spin-labeling method in six arrested rabbit hearts at 4. 7 T. Selective inversion of magnetization in the short-axis imaging se ction along with all myocardium apical to that section produces signal enhancement from arterial perfusion. A linescan protocol was used for validation of now enhancement. Flow was quantitated from two images a nd validated with spin-echo (SE) imaging. Regional perfusion defects w ere created by means of coronary artery ligation and delineated with g adolinium-enhanced imaging. RESULTS: Linescan estimates of T1 obtained at physiologic flows agreed with model predictions. Flow-induced sign al enhancement measured on-SE-images also agreed with expected values. Finally, perfusion abnormalities created by means of coronary artery ligation were detected. CONCLUSION: This spin-labeling method-provides quantitative estimates of myocardial arterial perfusion in this model and may hold promise for clinical applications.