Innovations in Instrumentation for Positron Emission Tomography

Eric Berg, Simon R. Cherry
2018 Seminars in nuclear medicine  
Positron emission tomography (PET) scanners are sophisticated and highly sensitive biomedical imaging devices that can produce highly quantitative images showing the three-dimensional distribution of radiotracers inside the body. PET scanners are commonly integrated with x-ray computed tomography (CT) or magnetic resonance imaging (MRI) scanners in hybrid devices that can provide both molecular imaging (PET) and anatomical imaging (CT or MRI). Despite decades of development, significant
more » ... ities still exist to make major improvements in the performance of PET systems for a variety of clinical and research tasks. These opportunities stem from new ideas and concepts, as well as a range of enabling technologies and methodologies. In this paper, we review current state of the art in PET instrumentation, detectors and systems, describe the major limitations in PET as currently practiced, and offer our own personal insights into some of the recent and emerging technological innovations that we believe will impact the field. Our focus is on the technical aspects of PET imaging, specifically detectors and system design, and the opportunity and necessity to move closer to PET systems for diagnostic patient use and in vivo biomedical research that truly approach the physical performance limits while remaining mindful of imaging time, radiation dose and cost. However, other key endeavors which are not covered here, including innovations in reconstruction and modeling methodology, radiotracer development, and expanding the range of clinical and research applications, also will play an equally important, if not more important, role in defining the future of the field. radionuclide decays to strike the detectors at almost the same time, thus appearing to produce a valid coincidence event. These are called random events. The number of both scattered and random events should be minimized to obtain the highest quality images, as Berg and Cherry The cost of a scanner, to first order, is related to the cost of its components, which, for a given bore size, mostly scales with the degree of geometric coverage, G. A scanner that covers twice the solid angle around the patient, assuming a fixed detector ring diameter, will require twice as many detectors and twice the number of channels of electronics. Thus, increasing G typically increases cost, while decreasing G decreases SNR. The key therefore for reducing cost while maximizing geometric sensitivity is likely through the development of detector materials that are more efficient and cost less for a given thickness. For example, Berg and Cherry
doi:10.1053/j.semnuclmed.2018.02.006 pmid:29852942 pmcid:PMC5986096 fatcat:bxdmzqiaqfbaxk77inelcr3ppy