MOUSE LEMUR MICROSCOPIC MRI BRAIN ATLAS

We present a three-dimensional (3D) digital atlas of a mouse lemur hea d at 60-mum cubic voxel isotropic resolution. It was constructed from a 3D proton magnetic resonance image (MRI) acquired at 500 MHz. It sho ws views of 3D volume-rendering and movies of contiguous 2D plane cuts in three orthogonal directions. This MR data set was acquired using a spin-echo pulse sequence under conditions of strong T2 and significan t diffusion weighting. Experimental parameters were optimized to provi de strong intrinsic contrast between gray and white matter. Familiar a natomical structures are clearly identifiable. Fine fiber tracts, lami nations of cortices, details of the inner ears, and layering in the la teral geniculate nuclei are all visible. Anatomical identifications of structures in representative slices selected from the atlas are prese nted. We also describe some difficulties and trade-offs encountered in microscopic resolution MRI. We note that this type of atlas does not suffer from the spatial distortions and slice registration problems in troduced by standard histological techniques. Future in vivo longitudi nal studies will provide atlases describing in detail the development of the primate brain. (C) 1994 Academic Press, Inc.