Noninvasive Imaging for Supporting Basic Research

Abstract

By providing a noninvasive means of quantitatively assaying biological structure and function in vivo, imaging of small laboratory animals (i.e., mice and rats) has emerged as a critical component of preclinical biomedical research. It allows serial assay of rodent models of human cancer and other diseases over the entire natural history of the disease process and monitoring of the effectiveness of treatment or other interventions. With the ongoing development of genetically engineered rodent models of human diseases, such models are increasingly more realistic in recapitulating the natural history and clinical sequelae of the corresponding human condition. The ability to track such models long term is therefore invaluable. This chapter provides a brief survey of current small-animal imaging modalities used in basic research – magnetic resonance imaging and spectroscopic imaging (MRI and MRSI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), transmission computed tomography (CT), ultrasound (US), and optical (bioluminescence and fluorescence) imaging – and of the probes and contrast agents used with these various modalities. Newer modalities, such as Cerenkov imaging, photoacoustic imaging, diffuse optical tomography, optical coherence tomography, and Raman spectroscopic imaging, are also briefly reviewed. Illustrative studies utilizing the foregoing modalities in preclinical research are presented as well.