1. A non-transitory computer readable storage medium having stored thereon a computer program comprising instructions which when executed by a computer cause the computer to: access a first anatomical image data set of an imaging subject acquired via a morphological imaging modality; access a functional image data set of the imaging subject acquired via a functional imaging modality that images at least one biological process; register the first anatomical image data set to the functional image data set; segment the functional image data set based on a region of physiological activity of the functional image data set; define a binary mask based on the segmented functional image data set; apply the binary mask to the first anatomical image data set to construct a second anatomical image data set, wherein the second anatomical image data set is substantially free of image data from the first anatomical image data set correlating to an area outside the region of physiological activity; and construct an image based on the second anatomical image data set.