Factor Analysis (2 TACs)

This model performs a factor analysis (FA) on dynamic data. Two TACs must be specified:

1. One TAC which reflects the temporal evolution of activity in the tissue of interest (variate TAC; e.g. myocardium in cardiac studies).
2. One TAC which reflects the temporal evolution of activity opposite to the tissue of interest (covariate TAC; e.g. ventricle in cardiac studies).

With these time activity curves a factor analysis is performed, resulting in two sets of factors (one factor per time). These factors are applied during pixel-wise processing to calculate the variate and covariate factor images.