Abstract #3397

Measuring Diffusion Tensor Parameters in the Human Hippocampus: Region of Interest Placement

Michael Yoong¹, Chris Clark², Rod Scott^2,3

¹Department of Neurosciences, Institute of Child Health, University College London, London, UK; ²Department of Biophysics, Institute of Child Health, University College London, London, UK; ³Department of Neurosciences, Institute of Child Health, Universitly College London, London, UK

There is inherent inaccuracy with manually placing regions of interest (ROI) within the hippocampus using diffusion images in order to measure parameters such as mean diffusivity/fractional anisotropy. Nevertheless as this remains a widely used method of analysis, it is important to maximise its reproducibility and precision. We compared several methods of ROI placement within the hippocampi of children having scans following prolonged seizures. The most precise results came from placing a small, fixed size ROI within the hippocampus. We also determined that the optimum ROI size for our scans was 12 voxels using a simple, easily reproducible technique.