3D-QALAS in COVID: a whole brain voxel-based investigation of relaxometry

Motivation: The effect of COVID-19 on the brain is not fully understood. Simultaneous 3D-acquisition of relaxometry parameters can indicate where microstructure has changed. Goal(s): To locate differences in T1, T2 and proton density in COVID-19 patients. Approach: 3D-QALAS was performed on 17 volunteers and 17 patients. Relaxometry and segmentation maps were calculated and warped to a common space to compare both groups. Results: T2 changes associated with COVID-19 were observed in left cerebellar white and grey matter and in WM of the brain stem and thalamus, along with increased right temporal and occipital T1 and PD, and decreased frontal T1, T2 and PD values. Impact: A voxel-based relaxometry analysis using 3D-QALAS data, including WM and PD, was performed for the first time, based on the hMRI toolbox. Different patterns of parameter changes were observed in several brain regions, possibly indicating different types of microstructural changes.