Coronary vessel wall MRI at 3.0 T using Time-Resolved Acquisition of Phase-Sensitive DIR (TRAPD): initial results in patients with risk factors for coronary artery disease

Abstract

Background Technical challenges still hinder coronary wall imaging for routine clinical utilization. These challenges include image degradation due to aperiodic intrinsic cardiac and chest wall respiratory motions and residual motion due to uncompensated heart-rate variability. The purpose of this study was to 1) develop a time-resolved acquisition of phase-sensitive DIR coronary vessel wall MRI technique that overcomes the loss of the orthogonality due to uncompensated residual motions, 2) investigate the associated improvement in coronary wall imaging success rate when compared to that of single image coronary wall imaging, and to 3) assess the ability of the technique to show a difference in vessel wall thickness between healthy subjects and subjects with risk factors for coronary artery disease (CAD). Methods A 3T single-slice time-resolved free-breathing PS-DIR (TRAPD) coronary vessel wall imaging sequence was implemented, validated in a flow phantom. The coronary arterial wall, using 3 to 5 cine-image measurements, were obtained of 26 subjects with at least one Framingham CAD risk factors and 12 healthy subjects without history or risk factors for CAD. Image quality was scored and assessed, wall thickness was automatically measured, and qualitative and quantitative comparisons were made between TRAPD and conventional singleimage wall measurements. Results Time resolved coronary vessel wall imaging using TRAPD successfully restored the negative polarity of lumen signal and enhanced lumen-wall contrast in the cine images in