Dear all,

I have a question regarding the DTI output files of TumorSim1.2. I suppose the warped and modified tensors (after insertion of the tumor) are contained in the "xxx_modified_dti.mha" output file. As an example, I consider those files from Niethammer's database on Longitude with Pathology Challenge , named "Sim_XXX_modified_dti.mha" (XXX ranging from 071 to 094). The dimensions of those images are 256x256x1086. The diffusion information is indeed stacked along the z-dimension. When one scrolls from slice 1 to slice 1086, one encounters six volumes, which are supposed to be maps of the six tensor components (Dxx, Dxy, Dxz, Dyy, Dyz, Dzz respectively). However, the maps do not appear to give this information. Whereas the second and third volume indeed seem to represent off-diagonal components of the tensors (e.g. lower intensity), the fifth one does not look like an off-diagonal component. As a consequence, we appear to have 4 on-diagonal components and 2 off-diagonal components? I opened the files with different viewers and they all confirmed that there is something odd about the DTI output files.

Moreover, the tumor appears abnormally bright or abnormally dark in the DTI output files, depending on the tensor component under consideration. As an example, I included a slice from the Dxx volume of Sim_071_modified_dti.mha.

Has anyone encountered the same problems or has anyone been able to fit realistically looking tensors to the diffusion data after insertion of the tumor?

Thanks in advance,
Tom Haeck