Title: Canine Hippocampal Formation Composited into Three-dimensional Structure Using MPRAGE Running head: MPRAGE and 3D canine hippocampal formation Authors:

This study was performed to anatomically illustrate the living canine hippocampal formation in three-dimensions (3D), and to evaluate its relationship to surrounding brain structures. Three normal beagle dogs were scanned on a MR scanner with inversion recovery segmented threedimensoinal gradient echo sequence (known as MP-RAGE: Magnetization Prepared Rapid Gradient Echo). The MRI data was manually segmented and reconstructed into a three-dimensional model using the 3D slicer software tool. From the three-dimensional model, the spatial relationships between hippocampal formation and surrounding structures were evaluated. With the increased spatial resolution and contrast of the MPRAGE, the canine hippocampal formation was easily depicted. The reconstructed three-dimensional image allows easy understanding of the hippocampal contour and demonstrates the structural relationship of the hippocampal formation to surrounding structures in vivo. Keyword: 3D, Canine, Hippocampal formation, MPRAGE