Diffusion MRI in the heart.
Diffusion MRI provides unique information on the structure, organization, and integrity of the myocardium without the need for exogenous contrast agents. Diffusion MRI in the heart, however, has proven technically challenging because of the intrinsic non-rigid deformation during the cardiac cycle, displacement of the myocardium due to respiratory motion, signal inhomogeneity within the thorax, and short transverse relaxation times. Recently developed accelerated diffusion-weighted MR acquisition sequences combined with advanced post-processing techniques have improved the accuracy and efficiency of diffusion MRI in the myocardium. In this review, we describe the solutions and approaches that have been developed to enable diffusion MRI of the heart in vivo, including a dual-gated stimulated echo approach, a velocity- (M1) or an acceleration- (M2) compensated pulsed gradient spin echo approach, and the use of principal component analysis filtering. The structure of the myocardium and the application of these techniques in ischemic heart disease are also briefly reviewed. The advent of clinical MR systems with stronger gradients will likely facilitate the translation of cardiac diffusion MRI into clinical use. The addition of diffusion MRI to the well-established set of cardiovascular imaging techniques should lead to new and complementary approaches for the diagnosis and evaluation of patients with heart disease. © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Choukri
C
Mekkaoui
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
Timothy G
TG
Reese
Department of Computer Science, Institute of Mathematics and Statistics, University of São Paulo, São Paulo, Brazil.
Marcel P
MP
Jackowski
Siemens Healthcare, Charlestown, MA, USA.
Himanshu
H
Bhat
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.|Cardiovascular Research Center, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
David E
DE
Sosnovik
D000818:Animals; D057791:Cardiac Imaging Techniques / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D019317:Evidence-Based Medicine; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
MRI; diffusion; heart; ischemia; myocardium; myofiber architecture; tensor; tractography