Magnetic resonance imaging of regional myocardial perfusion in patients with single-vessel coronary artery disease: Quantitative comparison with201Thallium-SPECT and coronary angiography

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Abstract
The clinical value of magnetic resonance perfusion imaging (MRI) was investigated by quantitative comparison with 201thallium‐single‐photon emission computed tomography (201TI‐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 regions. Defining a perfusion defect as a region with less than 90% of maximum 201TI intensity, nine patients had a matching perfusion defect, two had no defect on both 201TI‐SPECT or MRI, and one had a defect on 201TI‐SPECT but not on MRI. One patient had a defect on both modalities but with inaccurate localization. Three perfusion parameters were investigated: a) maximum contrast enhancement (MCE); b) slope of the signal intensity versus time curve; and c) inverse mean transit time (1/MTT). The sensitivity and specificity of MCE in the detection of perfusion abnormalities with TI‐SPECT as the reference method were 71% and 71%, respectively (slope 77% and 61%, 1/MTT 44% and 70%). Furthermore, correlations were calculated per patient for the entire circumference of the short‐axis myocardium. Median correlations were as follows: MCE 0.92, slope 0.91, and 1/MTT 0.40. Mismatches between 201TI defects and defects on MRI resulted in low mean correlations (MCE 0.45, slope 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). Thus, MRI and 201TI‐SPECT demonstrate fair agreement in the assessment of perfusion defects but show moderate correlation when the entire short‐axis myocardium is correlated. J. Magn. Reson. Imaging 2000;11:607–615.