q-Space Novelty Detection in Short Diffusion MRI Scans of Multiple Sclerosis

Synopsis Diffusion MRI captures disease-related microstructural changes, but so far establishing the relationship between q-space measurements and microstructure has required mathematical/physical representations which discard parts of the information and rely on unstable fitting procedures requiring quite long scan times. In contrast, q-space novelty detection (q-ND) circumvents these drawbacks, and does not require any knowledge whatsoever about the effect of disease on q-space measurements. Instead, q-ND highlights voxels that look unlike anything seen in a database of healthy scans. Here we show that novelty scores from q-ND largely coincide with multiple sclerosis lesions, and that q-ND also works at reduced scan times.