IDPs reduce raw data into a compact set of biologically-meaningful measures, with current measures condensing ~2GB raw data per subject into 2501 IDPs, but such summary measures can lose valuable information. For example, once aligned to common coordinate systems, images can be analysed for cross-subject variation at the voxel level to provide a more spatially-detailed exploration than can be achieved via IDPs. However, this requires greater imaging expertise and computational resources, as well as often leading to lower statistical power (due to the greatly increased number of multiple comparisons and the higher noise in voxel-wise measures compared with regional averages). Below, we present example voxel-wise associations with aging.
