Status of Clinical PET in the USA and the Role and Activities of the Institute for Clinical PET

Abstract

Modern Positron Emission Tomography (PET) scanners were developed in the early 1970s by Kuhl (1, 2), Ter-Pogossian (3) and Phelps (4). The principal motivation for the development of the coincidence imaging technology was to facilitate the study of cerebral physiology using positron emitting tracers such as¹⁵O oxygen and ¹⁵O water. Studies of cerebral blood flow and glucose metabolism were almost exclusively the focus of PET imaging until the 1980s when PET tomographs capable of accommodating the torso permitted extension of positron based tracers to cardiology. By the early 1990s studies of glucose metabolism in malignant neoplasms throughout the body emerged. Because PET was developed principally to answer scientific questions in an academic setting rather than provide clinical patient care, as was largely the case with CT and MRI, PET imaging remained in the province of academic institutions, considered primarily a research tool rather than a clinically useful technology. Potential clinical applications were nevertheless recognized and developed in neurology in the early 1980s, cardiology in the mid 1980s and oncology in the early 1990’s. Localization of epileptic foci, assessment of brain tumors, and differentiation of recurrent primary brain neoplasms from radiation necrosis were seen as useful applications of PET in clinical neurology. In cardiology, measurement of myocardial blood flow and determination of myocardial viability in zones of non-contractile myocardium were recognized as suitable clinical applications.