ABSTRACT
Molecular imaging is an emerging ™eld that can be broadly de™ned as in vivo visualization, characterization, and quanti™cation of biological processes at the cellular and molecular levels (Weissleder and Mahmood 2001; Massoud and Gambhir 2003). Conventional diagnostic imaging mostly measures nonspeci™c anatomic, physiological, or metabolic changes that mark pathological diŸerentiation of diseased tissues or conditions from healthy tissues. Molecular imaging, on the other hand, aims to probe the cellular and molecular pathways and changes that are the fundaments of diseases.
