4 January 2018 Measuring temporal stability of positron emission tomography standardized uptake value bias using long-lived sources in a multicenter network
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Abstract
Positron emission tomography (PET) is a quantitative imaging modality, but the computation of standardized uptake values (SUVs) requires several instruments to be correctly calibrated. Variability in the calibration process may lead to unreliable quantitation. Sealed source kits containing traceable amounts of Ge 68 / Ga 68 were used to measure signal stability for 19 PET scanners at nine hospitals in the National Cancer Institute’s Quantitative Imaging Network. Repeated measurements of the sources were performed on PET scanners and in dose calibrators. The measured scanner and dose calibrator signal biases were used to compute the bias in SUVs at multiple time points for each site over a 14-month period. Estimation of absolute SUV accuracy was confounded by bias from the solid phantoms’ physical properties. On average, the intrascanner coefficient of variation for SUV measurements was 3.5%. Over the entire length of the study, single-scanner SUV values varied over a range of 11%. Dose calibrator bias was not correlated with scanner bias. Calibration factors from the image metadata were nearly as variable as scanner signal, and were correlated with signal for many scanners. SUVs often showed low intrascanner variability between successive measurements but were also prone to shifts in apparent bias, possibly in part due to scanner recalibrations that are part of regular scanner quality control. Biases of key factors in the computation of SUVs were not correlated and their temporal variations did not cancel out of the computation. Long-lived sources and image metadata may provide a check on the recalibration process.
© 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Darrin Byrd, Darrin Byrd, Rebecca Christopfel, Rebecca Christopfel, Grae Arabasz, Grae Arabasz, Ciprian Catana, Ciprian Catana, Joel Karp, Joel Karp, Martin A. Lodge, Martin A. Lodge, Charles Laymon, Charles Laymon, Eduardo G. Moros, Eduardo G. Moros, Mikalai Budzevich, Mikalai Budzevich, Sadek Nehmeh, Sadek Nehmeh, Joshua Scheuermann, Joshua Scheuermann, John Sunderland, John Sunderland, Jun Zhang, Jun Zhang, Paul Kinahan, Paul Kinahan, } "Measuring temporal stability of positron emission tomography standardized uptake value bias using long-lived sources in a multicenter network," Journal of Medical Imaging 5(1), 011016 (4 January 2018). https://doi.org/10.1117/1.JMI.5.1.011016 . Submission: Received: 7 July 2017; Accepted: 20 November 2017
Received: 7 July 2017; Accepted: 20 November 2017; Published: 4 January 2018
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