1. An integrated microtomography and optical imaging system, comprising: a rotating table configured to support an imaging object, and to rotate the imaging object about a first axis running through the imaging object to a plurality of different rotational positions; an optical imaging apparatus configured to illuminate and obtain optical image information for the imaging object along one or more optical paths that are substantially parallel to the first axis while the imaging object is on the rotating table; a microtomography imaging apparatus configured to obtain microtomographic image information for the imaging object along one or more radiation paths that are substantially orthogonal to the first axis while the imaging object is on the rotating table; and an electronic processor connected to the optical imaging apparatus and the microtomography imaging apparatus and configured to combine the optical image information and the tomographic image information to obtain a representation of a three-dimensional distribution of light-emitting sources within the imaging object, wherein the optical image information corresponds to at least one of fluorescence emission from the imaging object and bioluminescence emission from the imaging object.