1. An image data processor, comprising: a structural image data processor that employs a multi-structure atlas to segment a region of interest from structural image data which includes tissue of interest and that segments the tissue of interests from the region of interest, wherein the structure is rib cage and the tissue of interest is lung lobe, and the multi-structure atlas is a rib cage/lung lobe atlas that includes a mapping that maps one or more ribs to a location of a boundary of a lung lobe, and the mapping includes a lung lobe region of interest, in a form of a least one of a point cloud on a surface of the lung or a 3D sheet across lung, through the rib case/lung lobe atlas; and a functional image data processor that identifies the tissue of interest in functional image data based on the segmented tissue of interest.