Magnetic resonance imaging of regional myocardial perfusion in patients with single-vessel coronary artery disease: Quantitative comparison with (201)thallium-SPECT and coronary angiography

The clinical value of magnetic resonance perfusion imaging (Mail) was inves tigated by quantitative comparison with (201)thallium-single-photon emissio n computed tomography (Tl-201-SPECT) and quantitative coronary angiography (QCA). Short-axis imaging was performed during dipyridamole administration in 13 patients with single-vessel coronary artery disease. Using inner and outer contours, the myocardium was divided into 30 contiguous, radial regio ns. Defining a perfusion defect as a region with less than 90% of maximum T l-201 intensity, nine patients had a matching perfusion defect, two had no defect on both Tl-201-SPECT or MRI, and one had a defect on Tl-201-SPECT bu t not on NM. One patient had a defect on both modalities but with inaccurat e localization. Three perfusion parameters were investigated: a) maximum co ntrast enhancement (MCE); b) slope of the signal intensity versus time curv e; and c) inverse mean transit time (1/MTT). The sensitivity and specificit y of MCE in the detection of perfusion abnormalities with TI-SPECT as the r eference method were 71% and 71%, respectively (slope 77% and 61%, 1/MTT 44 % and 70%). Furthermore, correlations were calculated per patient for the e ntire circumference of the short-axis myocardium. Median correlations were as follows: MCE 0.92, slope 0.91, and 1/MTT 0.40. Mismatches between Tl-201 defects and defects on MRI resulted in low mean correlations (MCE 0.45, sl ope 0.46, and 1/MTT 0.26). There was a trend between severity of perfusion defects on MRI (using MCE) and QCA stenosis area (r = -0.56, P = 0.06). Thu s, MRI and Tl-201-SPECT demonstrate fair agreement in the assessment of per fusion defects but show moderate correlation when the entire short-axis myo cardium is correlated. J. Magn. Reson. Imaging 2000;11:607-615. (C) 2000 Wi ley-Liss, Inc.