In Vivo Ultra-High Resolution Diffusion Tensor Imaging of the Microscopic Pathways of the Medial Temporal Lobe

Michael Zeineh¹, Samantha Holdsworth¹, Stefan Skare², Anh Van¹, Scott Atlas¹, Roland Bammer¹

Abnormal neuronal connectivity may be important in disease states involving the medial temporal lobes (MTL), including Alzheimers and epilepsy. Conventional DTI provides an inadequate depiction of the complex microanatomy in the MTL because of a typically employed low isotropic resolution of 2.0-2.5mm, a low signal-to-noise ratio, and echo-planar imaging geometric distortions. In this study, we push the resolving power of DTI to near-mm isotropic voxel size through optimized diffusion weighted imaging at 3.0T. Utilizing a detailed segmentation of the MTL, we can identify tracks in all subjects that may represent the major pathways of the MTL, including the perforant pathway.