Feasibility of cardiovascular magnetic resonance imaging at 5T in comparison to 3T

Abstract

Abstract Purpose Due to safety and technical issues, 7T MRI has not been approved by the FDA for cardiovascular magnetic resonance imaging (CMR), however, 5T has been proved to be safe for whole body imaging. In this study, we investigated the feasibility and performance of CMR at a 5T whole body system, which may face less technical challenges than 7T. Methods Seventeen healthy volunteers and three patients were recruited and underwent CMR scans on both 5T and 3T MR scanners. Cine images of short-axis views as well as three standard long-axis views were acquired at 3T using balanced steady state free precession sequence, and at 5T using fast gradient echo sequence respectively. Dark blood imaging was repeated in a slice of midventricular short-axis view at 5T and 3T as well. Image quality and artifact level were estimated on a 5-point scale and compared between different field strengths. Quantifications of functional parameters and mass of left ventricle (LV) were compared between the two field strengths. Results The overall image acquired at 5T was comparable to that obtained at 3T, achieving image quality scores of 4.61±0.39 and 4.59±0.56 for dark blood sequences, 4.60±0.50 for FGRE sequence. Artifact level scores for black blood sequences were 4.72±0.46 and4.65±0.54, while FGRE sequence achieved 4.65±0.49. Bland-Altman analysis demonstrated that functional parameters and mass of LV derived from 5T were in good agreement with the 3T counterparts. Conclusion This study confirmed the feasibility of CMR imaging at 5T MR system.