Program Information
Validation of a Novel Calibration Method Using a Traceable 68Ge/68Ga Point-Like Source On Eleven Types of PET Scanners
S Koyama1*, T Hasegawa2 , H Miyatake3 , Y Inoue4 , K Kikuchi5 , K Wagatsuma6 , N Miyaji7 , H Watabe8 , M Shidahara9 , S Watanuki10 , K Tsuda11 , Y Muramatsu12 , K Yanagisawa13 , Y Wada14 , K Oda15 , Y Sato16 , T Yamada17 , (1) Kitasato University Graduate School, Sagamihara, Kanagawa,, (2) Kitasato University, Sagamihara, Kanagawa, ,(3) Kitasato University Hospital, Sagamihara, Kanagawa, ,(4) Kitasato University Hospital, Sagamihara, Kanagawa, ,(5) Kitasato University Hosital, Sagamihara, Kanagawa, ,(6) Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo, ,(7) Japanese Foundation for Cancer Research, Koto-ku, Tokyo, ,(8) Tohoku University, Aoba-ku, Sendai, Miyagi, ,(9) Tohoku University, Aoba-ku, Sendai, Miyagi, ,(10) Tohoku University, Aoba-ku, Sendai, Miyagi, ,(11) Tsukuba International University, Tsuchiura, Ibaraki, ,(12) National Cancer Center hospital East, Kashiwa, Chiba, ,(13) National Cancer Center hospital East, Kashiwa, Chiba, ,(14) RIKEN Center for Life Science Technologies, Chuo-ku, Kobe, Hyogo, ,(15) Hokkaido University of Science, Sapporo, Hokkaido, ,(16) AIST, Tsukuba, Ibaraki, ,(17) JRIA, Bunkyo-ku, Tokyo,
Presentations
SU-I-GPD-I-11 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall
Purpose: In order to improve the reliability and simplicity of PET-scanner calibrations, we developed a novel calibration method based on the use of traceable point-like sources. The purpose of this study is to validate this novel calibration method on eleven different types of commercial PET scanners.
Methods: A traceable point-like ⁶⁸Ge/⁶⁸Ga source with a spherical acrylic absorber was used in this study. We tested nine types of clinical PET and PET/CT scanners, Biograph TruePoint, Biograph mCT Flow (Siemens), Discovery 600, Discovery 710, Discovery IQ (GE), SET 2400W, SET 3000BX, STARGATE (Shimadzu), Aquiduo16 (Toshiba), and two types of small-animal PET scanners, Clairvivo (Shimadzu) and microPET Focus 220 (Siemens). The point-like source was placed near the center of field of view (FOV). The images were reconstructed using the same methods as those used under clinical conditions except for scatter and attenuation corrections. Circular regions of interest (ROIs) with various ROI radii were defined around the source location to obtain the total ROI values. The total ROI values, multiplied by the pixel volume and divided by the source radioactivity, were used to generate recovery curves when plotted as functions of the ROI radius. Then, a fitting function was defined for calculating the calibration factors. The results were compared with those obtained by the standard cross-calibration method.
Results: The calibration factors obtained using the point-like source agreed with those obtained by the standard cross-calibration method within 5% except for the Clarvivo and microPET scanner. These results are reasonable, considering the inherent uncertainties of the proposed and standard calibration methods.
Conclusion: The calibration factors obtained by the proposed method agreed with those obtained by the standard cross-calibration method within reasonable uncertainty. The proposed calibration method thus shows much promise for evaluating and calibrating the quantitative aspects of PET scanners.
Funding Support, Disclosures, and Conflict of Interest: This study was supported in part by JSPS KAKENHI Grant Number JP15K08701 and a special research grant for Kitasato University Allied Health Sciences (Grant-in-Aid for Research Project, No. 2015-1011, 2016-1012)
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