Small animal molecular imaging in cancer research

Quantitative small animal imaging plays a key role in preclinical research and drug development. However, no single imaging modality is perfect and sufficient to gain all the necessary morphologic, physiologic, metabolic or genetic information. For instance, optical fluorescence imaging is difficult to quantify - especially in tissue more than a few millimetres in depth within a subject; magnetic resonance imaging of protons (MRI) has superb resolution but low sensitivity, positron emission tomography (PET) has very high sensitivity but poor resolution, single photon emission tomography (SPECT) has good resolution but low sensitivity and X-ray tomography (CT) has good resolution of bones but cannot good resolve tissues. The combination of multiple molecular imaging techniques can therefore offer synergistic advantages over any modality alone. The multimodal approach by combination of the methods and development of multimodal probes is far from trivial and a challenge for the interdisciplinary work and collaboration of scientists.
In the presentation we provide an overview of the small animal imaging in the Forschungszentrum Dresden-Rossendorf, recent developments of probes and applications in multimodal cancer research. We will show examples of quantitative imaging using low and high molecular weight probes and microspheres labeled for PET, SPECT and optical imaging. The especial developed animal bed system helps us to register the 3D data from different dedicated modalities for combining and comparing the methods. The development of imaging probes is embedded a combination of in vitro and ex vivo evaluation of gene expression, cell uptake and binding studies.
The molecular imaging in mouse and rat models allows us to ‘see’ the biological complexities of tumors for the treatment of this disease. This is one of the most exciting and growing areas in our research.