High-resolution emission tomography of small laboratory animals: physics and gamma-astronomy meet molecular biology

Molecular imaging can be defined as the characterization and measurement of biological processes in living animals, model systems and humans at the cellular and molecular level using remote imaging detectors. An example concerns the mapping of the distributions of radioactively labeled molecules in laboratory animals which is of crucial importance for life sciences. Tomographic methods like Single Photon Emission Computed Tomography (SPECT) offer a possibility to visualize distributions of radioactively labeled molecules in living animals. Miniature tomography systems, derived from their clinical counterparts, but with a much higher image resolution are under development in several institutes. An example is U-SPECT that will be discussed in the present paper. Such systems are expected to accelerate several biomedical research procedures, the understanding of gene and protein function, as well as pharmaceutical development.