Fig. 1.
Aim and design of the validation study of the EADC (European Alzheimer's Disease Consortium)-ADNI (Alzheimer's Disease Neuroimaging Initiative) Harmonized Protocol (HarP). Phase I: 21 naïve tracers segmented the hippocampi of 10 ADNI subjects (right and left, scanned at 1.5T and 3T, for a total of 40 hippocampi) balanced by atrophy following local protocols; qualified for the HarP; and then retraced the same hippocampi following the HarP. The total number of hippocampi was 80 per tracer. Phase II: the most accurate of the naïve tracers completing Phase I followed the HarP to segment 15 ADNI cases balanced by atrophy and scanner manufacturer and acquired at three time points at 1.5T and 3T; 20 baseline scans (already segmented in Phase I) were retraced in Phase II, while the other 10 baseline scans were blindly segmented twice within Phase II. The total number of hippocampi was 240 per tracer.