Fig. 3.

(a) Boxplot showing the percent change of cortical or total gray matter volume measured from each pipeline from one-year data after removing outliers. Jacobian integration and SIENAX measure cortical volume change while SPM measures total gray matter volume change. The colored boxplot shows the first quartile, median, third quartile, and extreme values; the black rectangle indicates the mean with standard error; the curves are the corresponding histograms. The darker curves use LPP, and lighter colors for XPP. Mean, standard deviation (SD), and effect size are shown below for each method. (b) The required sample size per arm for each pipeline for varying treatment effects with fixed power of 80% and 0.05 significance level. Table 1 shows the same values with 95% confidence interval. Values greater than 1000 are omitted here as such trials are not realistic. Cross-sectional FreeSurfer, FreeSurfer (x) values are not displayed because their values are above 1000. Abbreviations: XPP = cross-sectional pre-processing; LPP = longitudinal pre-processing.