cognitive impairment (LMCI), as well as 199 subjects suffering from Alzheimer’s disease (AD). We randomly picked roughly 1/6 of patients from each diagnostic category to form a set of 139 subjects for training in `ADNI-1`, i.e., 38 normal controls, 43 MCI, 25 LMCI, as well as 33 AD subjects; this results in 139 subjects overall. The baseline images of each subject were registered to *all* the later time-points within the same subject. To maintain the diagnostic ratio, we picked (out of all registrations) 45 registrations from the normal group, 50 registrations from the MCI group, 30 registrations from the LMCI group, and 40 registrations from the AD group, resulting in 165 longitudinal registration cases for training. 0.5ex The same strategy was applied to `ADNI-2`. In detail, `ADNI-2` contains 200 normal controls, 111 subjects with significant memory complaint (SMC), 182 subjects with early mild cognitive impairment (EMCI), 175 with late mild cognitive impairment (LMCI), and 155 subjects with Alzheimer’s disease (AD). We picked 150 subjects and 140 longitudinal registrations, consisting of 35 registrations from the control group, 20 registrations from the SMC group, 30 registrations from the EMCI group, 30 registrations from the LMCI group, and 25 registrations from the AD 