Characterization of 3-Dimensional PET Systems for Accurate Quantification of Myocardial Blood Flow
Jennifer M Renaud, Kathy Yip, Jean Guimond, Mikaël Trottier, Philippe Pibarot, Eric Turcotte, Conor Maguire, Lucille Lalonde, Karen Gulenchyn, Troy Farncombe, Gerald Wisenberg, Jonathan Moody, Benjamin Lee, Steven C Port, Timothy G Turkington, Rob S Beanlands, Robert A deKemp, Jennifer M Renaud, Kathy Yip, Jean Guimond, Mikaël Trottier, Philippe Pibarot, Eric Turcotte, Conor Maguire, Lucille Lalonde, Karen Gulenchyn, Troy Farncombe, Gerald Wisenberg, Jonathan Moody, Benjamin Lee, Steven C Port, Timothy G Turkington, Rob S Beanlands, Robert A deKemp
Abstract
Three-dimensional (3D) mode imaging is the current standard for PET/CT systems. Dynamic imaging for quantification of myocardial blood flow with short-lived tracers, such as 82Rb-chloride, requires accuracy to be maintained over a wide range of isotope activities and scanner counting rates. We proposed new performance standard measurements to characterize the dynamic range of PET systems for accurate quantitative imaging.
Methods: 82Rb or 13N-ammonia (1,100-3,000 MBq) was injected into the heart wall insert of an anthropomorphic torso phantom. A decaying isotope scan was obtained over 5 half-lives on 9 different 3D PET/CT systems and 1 3D/2-dimensional PET-only system. Dynamic images (28 × 15 s) were reconstructed using iterative algorithms with all corrections enabled. Dynamic range was defined as the maximum activity in the myocardial wall with less than 10% bias, from which corresponding dead-time, counting rates, and/or injected activity limits were established for each scanner. Scatter correction residual bias was estimated as the maximum cavity blood-to-myocardium activity ratio. Image quality was assessed via the coefficient of variation measuring nonuniformity of the left ventricular myocardium activity distribution.
Results: Maximum recommended injected activity/body weight, peak dead-time correction factor, counting rates, and residual scatter bias for accurate cardiac myocardial blood flow imaging were 3-14 MBq/kg, 1.5-4.0, 22-64 Mcps singles and 4-14 Mcps prompt coincidence counting rates, and 2%-10% on the investigated scanners. Nonuniformity of the myocardial activity distribution varied from 3% to 16%.
Conclusion: Accurate dynamic imaging is possible on the 10 3D PET systems if the maximum injected MBq/kg values are respected to limit peak dead-time losses during the bolus first-pass transit.
Keywords: 82Rb; cardiac positron emission tomography; dynamic range.
© 2017 by the Society of Nuclear Medicine and Molecular Imaging.
Source: PubMed