Breath-hold imaging of the coronary arteries using Quiescent-Interval Slice-Selective (QISS) magnetic resonance angiography: pilot study at 1.5 Tesla and 3 Tesla.

Robert R Edelman,W Li,I Koktzoglou,A Pursnani,M P.F Botelho,S Giri

doi:10.1186/s12968-015-0205-2

Abstract

BackgroundCoronary magnetic resonance angiography (MRA) is usually obtained with a free-breathing navigator-gated 3D acquisition. Our aim was to develop an alternative breath-hold approach that would allow the coronary arteries to be evaluated in a much shorter time and without risk of degradation by respiratory motion artifacts. For this purpose, we implemented a breath-hold, non-contrast-enhanced, quiescent-interval slice-selective (QISS) 2D technique. Sequence performance was compared at 1.5 and 3 Tesla using both radial and Cartesian k-space trajectories.MethodsThe left coronary circulation was imaged in six healthy subjects and two patients with coronary artery disease. Breath-hold QISS was compared with T2-prepared 2D balanced steady-state free-precession (bSSFP) and free-breathing, navigator-gated 3D bSSFP.ResultsApproximately 10 2.1-mm thick slices were acquired in a single ~20-s breath-hold using two-shot QISS. QISS contrast-to-noise ratio (CNR) was 1.5-fold higher at 3 Tesla than at 1.5 Tesla. Cartesian QISS provided the best coronary-to-myocardium CNR, whereas radial QISS provided the sharpest coronary images. QISS image quality exceeded that of free-breathing 3D coronary MRA with few artifacts at either field strength. Compared with T2-prepared 2D bSSFP, multi-slice capability was not restricted by the specific absorption rate at 3 Tesla and pericardial fluid signal was better suppressed. In addition to depicting the coronary arteries, QISS could image intra-cardiac structures, pericardium, and the aortic root in arbitrary slice orientations.ConclusionsBreath-hold QISS is a simple, versatile, and time-efficient method for coronary MRA that provides excellent image quality at both 1.5 and 3 Tesla. Image quality exceeded that of free-breathing, navigator-gated 3D MRA in a much shorter scan time. QISS also allowed rapid multi-slice bright-blood, diastolic phase imaging of the heart, which may have complementary value to multi-phase cine imaging. We conclude that, with further clinical validation, QISS might provide an efficient alternative to commonly used free-breathing coronary MRA techniques.

Highlights

Coronary magnetic resonance angiography (MRA) is usually obtained with a free-breathing navigator-gated 3D acquisition
A drawback of currently available free-breathing coronary imaging techniques is their dependence on the patient’s respiratory pattern, which can result in inconsistent image quality and unpredictably long scan times
contrast-to-noise ratio (CNR) between the coronaries and background myocardium, pericardial fat, and lung parenchyma was 49 % (37.0 ± 13.0 vs 24.8 ± 9.5), 42 % (50.7 ± 16.0 vs 35.7 ± 11.5) and 47 % (54.2 ± 17.9 vs 36.8 ± 12.4) higher with Cartesian sampling (P < 0.001); data expressed as mean ± standard deviation

Summary

Introduction

Coronary magnetic resonance angiography (MRA) is usually obtained with a free-breathing navigator-gated 3D acquisition. Our aim was to develop an alternative breath-hold approach that would allow the coronary arteries to be evaluated in a much shorter time and without risk of degradation by respiratory motion artifacts. For this purpose, we implemented a breath-hold, non-contrast-enhanced, quiescent-interval slice-selective (QISS) 2D technique. Aside from the recent introduction of quantitative T1 and T2 mapping sequences, cardiac imaging protocols in routine clinical use have remained largely stable over the last decade. A drawback of currently available free-breathing coronary imaging techniques is their dependence on the patient’s respiratory pattern, which can result in inconsistent image quality and unpredictably long scan times

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