Diagnostic Accuracy of Stress Perfusion CMR in Comparison With Quantitative Coronary Angiography

Abstract

Objective Our primary objective was to determine the sensitivity, specificity, and accuracy of fully quantitative stress perfusion CMR versus a reference standard of quantitative coronary angiography (QCA). We hypothesized that fully quantitative analysis of stress perfusion CMR would have high diagnostic accuracy for identifying significant coronary artery stenosis and exceed the accuracy of semi-quantitative measures of perfusion and qualitative interpretation. Background Relatively few studies apply fully quantitative CMR perfusion measures to patients with coronary disease and comparisons to semi-quantitative and qualitative methods are limited. Methods Dual bolus dipyridamole stress perfusion CMR exams were performed in 67 patients with clinical indications for assessment of myocardial ischemia. Stress perfusion images alone were analyzed with a fully quantitative method (QP) and 3 semi-quantitative methods including contrast enhancement ratio (CER), upslope index (SLP), and upslope integral (INT). Comprehensive exams (cine imaging, stress/rest perfusion, late gadolinium enhancement) were analyzed qualitatively with two methods including the Duke Algorithm and standard clinical interpretation. A 70% or greater stenosis by QCA was considered abnormal. Results The optimum diagnostic threshold for QP determined by receiver operating characteristic curve occurred when endocardial flow decreased to <50% of mean epicardial flow which yielded a sensitivity of 87% and specificity of 93%. The area under the curve (AUC) for QP was 0.92 which was superior to semi-quantitative methods: CER 0.78, SLP 0.82, and INT 0.75 (p=0.011, p=0.019, p=0.004 versus QP, respectively). AUC for QP was also superior to qualitative methods: Duke Algorithm 0.70 and clinical interpretation 0.78 (p<0.001 and p<0.001 versus QP, respectively). Conclusions Fully quantitative stress perfusion CMR has high diagnostic accuracy for detecting obstructive CAD. QP outperforms semi-quantitative measures of perfusion and qualitative methods that incorporate a combination of cine, perfusion, and late gadolinium enhancement imaging. These findings suggest a potential clinical role for quantitative stress perfusion CMR.

Diagnostic Accuracy of Endocardial-to-Epicardial Myocardial Blood Flow Ratio for the Detection of Significant Coronary Artery Disease With Dynamic Myocardial Perfusion Dual-Source Computed Tomography

“…6-10 Because it is well established that the endocardial layer is more susceptible to ischemia and that perfusion of epicardial layers is relatively spared, even in the presence of severe coronary stenosis, one can assume that the relative flow index focussing on the difference between the endocardium and epicardium accurately reflects stenosis severity better than absolute thresholds. 17 Indeed, the TPR of absolute MBF, a ratio of endocardial MBF and epicardial MBF, improved the accuracy of stress dynamic CT for the detection of flowlimiting CAD in our study.…”

Infarct characterization using CT

“…SPECT and PET provided relevant diagnostic information with significant therapeutic and prognostic implications (70), despite some disadvantages such as attenuation artifacts, radiation dose, and limited off-hours availability. CMR may provide similar results in terms of diagnostic accuracy and long-term prognostic value, with the advantage of the lack of ionizing radiation (71,72).…”

Advanced Noninvasive Cardiac Imaging using Cardiac Magnetic Resonance Imaging in the Diagnosis and Evaluation of Coronary Artery Disease

“…Perfusion MRI is commonly achieved using a T1-weighted sequence to visualize the first passage of a gadolinium contrast agent. Since the signal intensity correlates with the contrast concentration, perfusion MRI analysis can be performed in a quantitative, semiquantitative, or qualitative fashion (14). Visual interpretation is most commonly performed to identify dark areas of hypoperfusion relative to the normally perfused myocardium (Fig.…”