Described in detail in a recent paper (Malone et al. MIRIAD–Public release of a multiple time point Alzheimer’s MR imaging dataset. Neuroimage. 2013;70: 33), the Minimal Interval Resonance Imaging in Alzheimer’s Disease (MIRIAD) dataset hosted by University College London is a series of longitudinal volumetric T1 MRI scans of 46 mild– moderate Alzheimer’s subjects and 23 controls. It consists of 708 scans conducted by the same radiographer with the same scanner and sequences at intervals of 2, 6, 14, 26, 38 and 52 weeks, 18 and 24 months from baseline, with accompanying information on gender, age and Mini Mental State Examination (MMSE) scores. 
Details of the cohort and imaging results are described in the Malone et al. paper, and the data have been made publicly available as a common resource for researchers to develop, validate and compare techniques, particularly for measurement of longitudinal volume change in serially acquired MR. Many scans were collected from each participant at intervals from 2 weeks to 2 years, the study was designed to investigate the feasibility of using MRI as an outcome measure for clinical trials of Alzheimer’s treatments. These include finding the minimal interval over which trials would need to be conducted; assessing whether combining more than two scanning time points would increase statistical power; assessing the reproducibility of techniques within a single day and over short intervals where changes in individual’s hydration and scanner fluctuations, but not pathological atrophy, might be expected.
