ABSTRACT
Since radiation detectors were first used in the 1950s to noninvasively image the distribution of radiolabeled tracers in the body, animals have been used to test new radiopharmaceuticals and imaging methods and to better understand the pathophysiology of disease. Until relatively recently, such studies were conducted using the same instrumentation and methods as those used in human studies. This approach delivered satisfactory results when imaging large animals, such as dogs and sheep, but clinical SPECT and PET scanners have inadequate spatial resolution and sensitivity for imaging smaller animals, such as rodents.
