Mekkaoui, ChoukriNielles-Vallespin, SoniaGatehouse, Peter DJackowski, Marcel PFirmin, David NSosnovik, David2012-08-102012Mekkaoui, Choukri, Sonia Nielles-Vallespin, Peter D Gatehouse, Marcel P Jackowski, David N Firmin, and David E Sosnovik. 2012. Diffusion MRI tractography of the human heart \(in\) \(vivo\) at end-diastole and end-systole. Journal of Cardiovascular Magnetic Resonance 14(Suppl 1): O49.1097-6647http://nrs.harvard.edu/urn-3:HUL.InstRepos:9393005Diffusion Tensor MRI (DTI) of the human heart \(in\) \(vivo\) has to date been performed in 2D and at a single phase of the cardiac cycle. Here we perform 3D tractography of the human heart \(in\) \(vivo\) at both end diastole and end systole. We show that fiber orientation in the subepicardium becomes more oblique during systole, and that scalar indices of diffusion (mean diffusivity and fractional anisotropy) decrease during systole. Our data suggest that myocardial fiber architecture is dynamic and is a function of both chamber geometry and myocardial contraction.en-USJournal Article2012-08-1010.1186/1532-429X-14-S1-O49