Purpose: The aim of this study was to implement and optimize a novel application of diffusion-prepared balanced steady-state free precession (bSSFP) to perform in vivo cardiac diffusion-weighted MRI.
Theory and methods: Diffusion-prepared sequences have the flexibility to diffusion encode with a multi-shot image readout. The diffusion preparation was optimized to reduce sensitivity to cardiac bulk motion with second order motion compensation (M1M2). The image readout consisted of a three-dimensional (3D) centric-encoded segmented bSSFP acquisition that incorporated a prospective navigator. Ten healthy subjects were scanned twice using the proposed technique diffusion preparation with and without M1M2 using three orthogonal directions under varying off-resonance conditions. Trace apparent diffusion coefficient (trADC) maps and the left ventricular (LV) trADC were calculated.
Results: M1M2 diffusion-prepared scans resulted in LV trADC values of 1.5 ± 0.4 × 10(-3) mm(2)/s that were reproducible yielding no statistical differences (P = 0.54). M1M2 diffusion-prepared images showed no ghosting artifacts and/or signal fallout. The non-motion-compensated diffusion-prepared scans yielded LV trADC values of 6.6 ± 0.9 × 10(-3) mm(2)/s and diffusion-prepared images with severe bulk motion-induced artifacts.
Conclusion: We developed a novel free-breathing bulk motion compensated diffusion-prepared 3D segmented bSSFP technique able to perform in vivo cardiac diffusion-weighted MRI on a conventional clinical MR scanner.
Keywords: bSSFP; cardiovascular MRI; diffusion preparation; motion compensation.
Copyright © 2013 Wiley Periodicals, Inc.