ABSTRACT
OBJECTIVE: MR myocardial perfusion imaging (MRMPI) is an established technique for the evaluation of the hemodynamical relevance of coronary artery disease. Perfusion imaging at 3.0T provides certain advantages compared to 1.5T. Aim of this study was to evaluate myocardial MR perfusion imaging at 3.0T. MATERIALS AND METHODS: Twelve patients with stable Angina pectoris and known or suspected coronary artery disease were examined at 3.0T. Myocardial perfusion was assessed using a saturation recovery gradient echo 2D sequence (TR 1.9ms, TE 1.0ms, FA 12 degrees ) with 0.05mmol Gd-DTPA per kg body weight at stress during injection of 140microg adenosine/kg body weight/min and at rest in short axis orientation. Perfusion analysis was based on a least square fit of the signal/time curve (peak signal intensity, slope). Perfusion series were assessed by two independent observers. Reference for the presence of relevant coronary artery stenoses was invasive coronary angiography. Two experienced observers evaluated the coronary angiograms in biplane projections for the presence and grade of stenoses. Results were compared with the MR perfusion analysis. RESULTS: All MR examinations could be safely performed and yielded high image quality. In eight patients stress-induced hypoperfusion was detected (stenosis >70% in coronary angiography). In four patients myocardial hypoperfusion was ruled out (stenosis <70%). The myocardial perfusion reserve index was significantly reduced in hypoperfused myocardium with 1.9+/-1.6 compared to 2.5+/-1.6 in regularly perfused myocardium (p<0.05). In coronary angiography, eight patients were found to suffer from coronary artery disease, whereas in four patients coronary artery disease was ruled out. CONCLUSION: Our initial results show that MRMPI at 3.0T provides reliably high-image quality and diagnostic accuracy.
Subject(s)
Coronary Artery Disease/diagnosis , Image Enhancement/methods , Magnetic Resonance Imaging/methods , Aged , Female , Humans , Male , Middle Aged , Pilot Projects , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
PURPOSE: The aim of the present study was to determine the correlation of myocardial perfusion MR imaging (MPMRI) and coronary angiography for the detection of flow-limiting stenosis in symptomatic patients with known coronary artery disease and a history of intervention. MATERIALS AND METHODS: MPMRI was performed in 51 symptomatic patients (44 male, 64.7 +/- 9.5 years) with known coronary artery disease and a history of stent implantation (between 5 years and 2 weeks prior to MRI). Malperfused myocardial regions were correlated with findings of coronary angiography. A stenosis of > 70% was regarded as hemodynamically significant. RESULTS: In MPMRI 37 patients (73%) showed a stress induced perfusion deficit. In 35 of these patients coronary angiography revealed a stenosis of > 70 %. A total of 38 patients (75%) showed stenoses of > 70%. MPMRI yielded a sensitivity of 92% with a specificity of 85 %. The positive predictive value was 95 % and negative predictive value was 79%. The assignment of malperfused segments to coronary artery territories was carried out according to the standardized myocardial model of the American Heart Association (sensitivity/specificity was 59/85% for RCA, 79/81% for LAD and 54/68 % for LCX). CONCLUSION: MPMRI is a suitable non-invasive method for detecting flow-limiting coronary artery stenoses in patients with a history of stent implantation.
