1. A system comprising: (a) a receiver circuit configured to receive (i) a medical image that includes a region of interest of a mammalian body part, and (ii) a reference image that includes a landmark subsurface feature of the mammalian body part, the landmark subsurface feature having a spatial relationship to the region of interest; (b) a registration circuit configured to register the region of interest and the landmark subsurface feature of the mammalian body part; and (c) computer-readable media configured to maintain informational data corresponding to the registration of the region of interest and the landmark subsurface feature of the mammalian body part.