Quantitative three-dimensional cardiovascular magnetic resonance myocardial perfusion imaging in systole and diastole

Abstract

BackgroundTwo-dimensional (2D) perfusion cardiovascular magnetic resonance (CMR) remains limited by a lack of complete myocardial coverage. Three-dimensional (3D) perfusion CMR addresses this limitation and has recently been shown to be clinically feasible. However, the feasibility and potential clinical utility of quantitative 3D perfusion measurements, as already shown with 2D-perfusion CMR and positron emission tomography, has yet to be evaluated. The influence of systolic or diastolic acquisition on myocardial blood flow (MBF) estimates, diagnostic accuracy and image quality is also unknown for 3D-perfusion CMR. The purpose of this study was to establish the feasibility of quantitative 3D-perfusion CMR for the detection of coronary artery disease (CAD) and to compare systolic and diastolic estimates of MBF.MethodsThirty-five patients underwent 3D-perfusion CMR with data acquired at both end-systole and mid-diastole. MBF and myocardial perfusion reserve (MPR) were estimated on a per patient and per territory basis by Fermi-constrained deconvolution. Significant CAD was defined as stenosis ≥70% on quantitative coronary angiography.ResultsTwenty patients had significant CAD (involving 38 out of 105 territories). Stress MBF and MPR had a high diagnostic accuracy for the detection of CAD in both systole (area under curve [AUC]: 0.95 and 0.92, respectively) and diastole (AUC: 0.95 and 0.94). There were no significant differences in the AUCs between systole and diastole (p values >0.05). At stress, diastolic MBF estimates were significantly greater than systolic estimates (no CAD: 3.21 ± 0.50 vs. 2.75 ± 0.42 ml/g/min, p < 0.0001; CAD: 2.13 ± 0.45 vs. 1.98 ± 0.41 ml/g/min, p < 0.0001); but at rest, there were no significant differences (p values >0.05). Image quality was higher in systole than diastole (median score 3 vs. 2, p = 0.002).ConclusionsQuantitative 3D-perfusion CMR is feasible. Estimates of MBF are significantly different for systole and diastole at stress but diagnostic accuracy to detect CAD is high for both cardiac phases. Better image quality suggests that systolic data acquisition may be preferable.

Review of Journal of Cardiovascular Magnetic Resonance 2015

“…Recent advances reported in the journal have included improved flow mapping, [1–3] real-time imaging, [4] T1 mapping, [5–7] simulations, [8, 9] perfusion, [10–12] coronary imaging, [13] diffusion tensor imaging, [14–16] feature tracking, [17–20] and strain assessment. [21, 22] The full breadth of new developments is described in the papers in the section.…”

PET/MRI of the Heart

“…29 By using electrocardiogram-triggered MRI acquisitions, a time resolution of three to six slices per cardiac cycle can be achieved with reasonable signal-to-noise ratio, also surpassing the temporal capabilities of PET imaging. However, one of the most important goals in recent research on cardiac perfusion MRI is to increase the spatial coverage of the heart muscle using either three-dimensional sequences or accelerated multislice approaches, which despite recent advances 30,31 is still lagging behind the whole heart coverage of PET. With the advent of integrated PET/MRI systems, equivalent coverage of the myocardium with PET and MRI perfusion imaging becomes highly desirable when comparing results between modalities or developing complementary imaging schemes.…”

Quantitative 3D myocardial perfusion with an efficient arterial input function

“…However, measuring perfusion at end systole further limits the acquisition window to 150 ms or less to avoid cardiac motion artifacts . Both the Motwani et al (192 ms acquisition window) and the Manka et al (200 ms acquisition window) studies exceed that suggested limit …”

“…Resting myocardial perfusion can identify microvascular obstruction, but myocardial perfusion reserve (MPR) is a more sensitive measurement of microvascular function and a strong surrogate marker for ischemia . The increased complexity of using a vasodilator agent and the shorter acquisition window associated with stress perfusion have limited the measurement of MPR using 3D cardiac perfusion to only a few reported studies . In addition, even though MR estimates of perfusion at systole and diastole have shown similar diagnostic accuracy, most sources agree that imaging at end systole is preferable due to the increased myocardium wall thickness .…”

“…19 Recent advances in pulse sequence design and image reconstruction [20][21][22][23] have begun to address this issue and a limited number of 3D cardiac perfusion studies have been reported. 4,[24][25][26][27][28][29][30][31][32] Despite these advances, none of the reported studies address all of the important clinical considerations discussed below.…”