Invited Talk by Lorenz König

Lorenz König Center for Brain Health Department of Psychiatry New York University Medical Center Date: Friday, June 29, 2012 Time: 11:00 - 12:00 Location: MI 03.13.010

On the Significance of Single Voxels: Edge Aberration and Sub-Voxel Segmentation in MRI

When analyzing raster images with respect to structures smaller than the voxel dimensions, it is of great importance to have a thorough understanding of the discretization of the image, hence the significance of single voxels. As an example, direct application of conventional models for sub-voxel edge detection to modalities with intricate image formation like MRI results in systematic edge dislocations on a sub-voxel scale (edge aberration). However, by quantitative experimental analysis of this effect, a simple correction term can be calibrated, which is capable of improving edge localization precision to surpass voxel size by 2 orders of magnitude. Starting from general considerations on image formation and focusing exemplarily on MRI, this talk explores the limits of local interpretation of raster images and points out possible solutions especially with regard to edge detection and segmentation.