Fluorescence molecular imaging: Microscopic to macroscopic

Medical imaging has revolutionized our understanding and ability to monitor specific macroscopic physical, physiological, and metabolic functions at cellular and subcellular levels. In the years to come, it will enable detection and characterization of disease even before anatomic changes become apparent. Fluorescence molecular imaging is revolutionarizing drug discovery and development with real-time in vivo monitoring in intact tissues. Technological advancements have taken fluorescence based imaging from microscopy to preclinical and clinical instruments for medical imaging. This chapter describes the current state of technology associated with in vivo noninvasive or minimally invasive fluorescence imaging along with the underlying principles. An overview of microscopic and macroscopic fluorescence imaging techniques is presented and their role in the development and applications of exogenous fluorescence contrast agents is discussed.