Positron Emission Tomography
Positron emission tomography (PET) is a noninvasive imaging method used to obtain quantitative molecular and biochemical information about physiological processes in the body. In other words, PET imaging can show the chemical functioning of organs and tissues in the living object. The concept of positron emission imaging was already developed in 1951 and the first human studies were published in 1953. Since then, fundamental technical developments in such fields as electronics, computer science, biology and biochemistry have significantly advanced the development of positron emission imaging techniques.
PET can help to advance a range of applications. It can be a powerful tool in drug discovery and development, for example, as it can noninvasively assess drug distribution and action at the molecular level. Preliminary studies indicate that dynamic PET imaging - using repeated images over time - can be a valuable technique for defining the time course of uptake and retention of radiolabeled anticancer drugs in tumors and in the surrounding normal tissue in patients. These drugs are designed to inhibit key processes in cancer initiation and progression: angiogenesis, proliferation, avoidance of cell death or apoptosis, invasion and metastasis, and transduction of signals that modulate these processes. In the clinical environment PET has established its efficacy in cancer studies, though these studies have only begun to utilize the full potential of PET imaging.