The numeric output of VOI statistics as well as the numerical output of other tools can be compiled into a single aggregate file for further statistic analysis. Aggregation is supported for
▪VOI statistics (.voistat files);
▪kinetic tissue parameters from the PKIN tool (.kinPar files);
▪the cardiac perfusion results of PCARD tool(.pcardRes files);
▪the discrimination results of the PALZ tool (.palzRes files).
Each of the tools has an appropriate button 
for starting the aggregation tool, and the aggregation interface works similarly.
Recommended Data Organization
Typically, the results of a population (control group, subject group) in a certain condition (test, retest) should be compiled into a single aggregate, and comparisons or tests performed between the aggregates.
It is recommended using the labeling facility of PMOD databases which allows defining a Project (Prj) and Group (Grp) label on the level of the image series. This information can be used for results filtering as described below.
In the example used below a VOI analysis has been performed with consistent VOI names using a brain VOI atlas and the results were saved with appropriate component names.