1. A system for generating a model relating parameters generated via a first molecular imaging modality to parameters generated via a second molecular imaging modality, the system comprising: a first feature extractor configured to extract, from a first image of a region of interest obtained via the first molecular imaging modality, a set of parameters for each of a first set of locations associated with the first image; a second feature extractor configured to extract, from a second image of a region of interest obtained via the second molecular imaging modality, a set of parameters for each of a second set of locations associated with the second image; a spatial registration component configured to associate respective locations of the first and second sets of locations according to their spatial relationship within the region of interest to produce a training set, wherein each example in the training set comprises a set of parameters associated with a location in the first set of locations and a set of parameters associated with a location in the second set of locations; and a modeling component configured to generate a predictive model relating the parameters associated with the first molecular imaging modality with at least one parameter associated with the second molecular imaging modality.