Direct histological validation of diffusion tensor MRI in formaldehyde-fixed myocardium

Diffusion tensor MRI is emerging as a rapid, nondestructive method to map m yocardial fiber organization. It accurately measures myofiber orientation i n hearts bathed in or perfused with cardioplegic solution. This study shows it also accurately maps the fibrous architecture of formalin-fixed hearts. Fiber orientations obtained by MRI and histology at the same locations in an excised portion of rabbit ventricle differed on average by 3.7 degrees ( SD = 6.4 degrees, N = 70), a closer correspondence than achieved with previ ous preparations. The longer acquisition times afforded by fixed-heart imag ing provides better accuracy, and should enable high-resolution reconstruct ion of the entire ventricular architecture. (C) 2000 Wiley-Liss, Inc.