Combined multi-spectral quantitative MRI and volumetry of the brain with the mixed-TSE pulse sequence and bisecting dual- clustering segmentation: a technique for studying regional ageing patterns in large populations

Introduction: Evolution of the brain during life can be divided in three time periods: a period of maturation characterized by increasing myelination and brain growth, an intermediate adulthood period characterized by relative stability, and an ageing period marked by ventricular enlargement, brain atrophy, and white matter (WM) and gray matter (GM) deterioration. Furthermore, these brain evolution during these three periods’ exhibit specific regional trends (Ref.1, 2). Multi-spectral quantitative MR imaging (Q-MRI) and image based volumetry are useful tools for characterizing the biological state of tissues (e.g. hydration level) and overall size of organs respectively. These two complementary tissue/organ characterizations are typically obtained from separate MRI scans, which may differ in imaging positioning and/or spatial resolution. Purpose: To develop a combined multi-spectral Q-MRI and volumetry technique for