MYOCARDIAL PERFUSION RESERVE - ASSESSMENT WITH MULTISECTION, QUANTITATIVE, FIRST-PASS MR-IMAGING

PURPOSE: To demonstrate the feasibility of determining myocardial bloo d now changes and the myocardial perfusion reserve with magnetic reson ance (MR) first-pass imaging, to validate the MR results by means of c omparison with radiolabeled microsphere now measurements in an animal model, and to compare the coronary now reserve with the perfusion rese rve at MR imaging in patients with hemodynamically nonsignificant coro nary lesions and angina. MATERIALS AND METHODS: Arrhythmia-insensitive , first-pass, multisection, TI-weighted MR imaging with contrast agent enhancement was performed in eight pigs with acute ischemia and in ei ght adult patients (six women, two men). In the pigs, microsphere now measurements were obtained in parallel with the MR measurements. In th e patients, the coronary now reserve was measured with an intracoronar y Doppler now ultrasound probe for comparison with the MR perfusion re serve. RESULTS: In the animal studies, there was linear correlation be tween MR perfusion indexes and the microsphere flow measurements (r = .88, P < .01). In the patients, the regional perfusion reserve matched the coronary flow reserve (linear regression with a slope of 1.02 +/- 0.09, r = .80). CONCLUSION: The myocardial perfusion reserve can be q uantified with first-pass MR imaging. In patients with microvascular d ysfunction, the myocardial perfusion reserve matches the reduced coron ary Bow reserve.