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. 2025 May;9(5):531-541.
doi: 10.1109/trpms.2024.3517421. Epub 2024 Dec 13.

Energy Scale-Factor Estimation for Use in Photomultiplier Tube Energy Calibration Using C-SPECT

Dale J Stentz  1 , Poopalasingam Sankar  1 , Lindsay C Johnson  1 , Scott D Metzler  1
Affiliations

Energy Scale-Factor Estimation for Use in Photomultiplier Tube Energy Calibration Using C-SPECT

Dale J Stentz et al. IEEE Trans Radiat Plasma Med Sci. 2025 May.

Abstract

An array of photomultiplier tubes (PMTs) provides energy readout for gamma cameras, leading to event selection and positioning. However, operational and environmental changes, such as temperature, can cause PMTs to "drift" away from their nominal energy readouts and, therefore, require a correction procedure to return to their reference energies. We present two methods for determining the energy-scale change of each PMT using data collected on C-SPECT, a dedicated cardiac single photon emission computational tomography (SPECT) scanner. A scan of a vertical line source of 99mTc provides the data from which we produce an energy histogram for each of the 130 PMTs. Each energy histogram is composed of events passing an energy-fraction selection to give events closest to the PMT center. We consider energy fractions ranging from 0.25% to 5.00%. For our analysis, we use bootstrapping to create data realizations as well as emulating energy-scale changes (simultaneously and independently for all PMTs) in the data. Using the average relative error as a measurement of the accuracy and the standard deviation from taking bootstrapped replicates of our data as a measurement of our precision, we determine the energy-scaling to within -0.05% ± 0.03% (mean and standard deviation, respectively).

Keywords: C-SPECT; Energy Calibration; Gamma Camera; Photomultiplier Tubes (PMT); SPECT.

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References

    1. Anger HO, “Use of a gamma-ray pinhole camera for in vivo studies,” Nature, vol. 170, pp. 200–201, Aug. 1952. - PubMed
    1. Anger HO, “Scintillation Camera,” Rev. Sci. Instrum, vol. 29, pp. 27–33, Jan. 1958.
    1. Peterson TE and Furenlid LR, “SPECT detectors: the Anger Camera and beyond,” Phys. Med. Biol, vol. 56, pp. R145–R182, Sep. 2011, doi: 10.1088/0031-9155/56/17/R01. - DOI - PMC - PubMed
    1. Graham LS, “Automatic Tuning of Scintillation Cameras: A Review,” J. Nucl. Med. Technol, vol. 14, no. 2, pp. 105–110, June 1986.
    1. Cherry SR, Sorenson JA, Phelphs ME, “The Gamma Camera: Performance Characteristics,” in Physics in Nuclear Medicine, 4th ed. Philadelphia, PA, USA: Saunders, 2012, ch. 14, pp. 209–231.