27 mm Diameter (Designed to fit 28 mm or smaller bore/bed sizes)
34 mm Diameter (Designed to fit 35 mm or smaller bore/bed sizes)
49 mm Diameter (Designed to fit 50 mm or smaller bore/bed sizes)
What are Partial Volume Effects (PVEs)?
PVEs are an inherent physical phenomenon present in all imaging systems largely due to sampling, blurring, motion, and physical hardware constraints. However, in nuclear medicine (particularly with PET and SPECT imaging), PVEs are compounded by a radioisotope’s finite positron emission energy and its respective inherent mean positron range. For a radioisotope with a relatively short positron range (ie. 18F in a static system, the intrinsic spatial resolution of the PET scanner will have a greater influence on partial volume effects (PVEs) than the positron range of the radioisotope. On the other hand, radioisotopes with relatively long positron ranges (ie. 124I, 89Zr) are largely responsible for PVEs due to the displacement of the originating positron emission voxel to the detected annihilation voxel. In either case, PVEs play a major role in the precision and accuracy of quantitative PET data, particularly with the degradation of measured radiotracer concentration in smaller structures using radioisotopes with long positron ranges.
Why do I need to correct for PVEs?
PVEs contribute to imprecise and inaccurate quantitative data in ALL of the approximately 2 million clinical positron emission tomography (PET) and ~14.5 million single-photon emission computed tomography (SPECT) scans per year, and tens of millions of preclinical PET and SPECT scans per year. Clinically, not correcting for PVEs can have serious negative consequences on patient management and outcomes, including but not limited to, progressive disease, radiotoxicity of normal tissue in theranostic applications, erroneous staging and prognosis, and the inability to compare data in multi-site trials, which collectively contribute to increased healthcare costs. Preclinically, not correcting for PVEs can have serious negative consequences as well, including but not limited to, erroneous data interpretation and conclusions, radiotoxicity of normal tissue in theranostic applications, and the inability to compare data between institutions.