Abstract #0017

Beyond Qualitative Tractography: A Novel & Reproducible Technique for the Quantitative Analysis of Cardiac Diffusion MR Tractography Datasets In Vivo

Choukri Mekkaoui¹, Shuning Huang¹, Guangping Dai¹, Timothy G. Reese¹, Udo Hoffmann², Marcel P. Jackowski³, David E. Sosnovik¹

¹Radiology, Harvard Medical School, Massachusetts General Hospital, Martinos Center For Biomedical Imaging, Charlestown, MA, USA; ²Radiology, Massachusetts General Hospital, Harvard Medical School, USA; ³Computer Science, University of So Paulo, Institute of Mathematics & Statistics, So Paulo, Brazil

Diffusion tensor MRI tractography can be used to resolve 3D myofiber architecture in the heart. The analysis of these tractograms, however, has been purely qualitative. Here we present a novel metric to quantify regional variation and measurement noise in diffusion tractography datasets in the heart. The technique is applied in human hearts ex vivo, in infarcted sheep hearts, and in mouse hearts in vivo. The use of this metric revealed that high quality diffusion tractograms of the mouse heart can be acquired in vivo, and that fibers in the remote zone of an infarct undergo a right-handed helix angle rotation.