TY - JOUR T1 - The possibility of the continuous bed motion method replacing the traditional step-and-shoot method by using a SiPM-PET/CT scanner. JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 3042 LP - 3042 VL - 62 IS - supplement 1 AU - Kodai Kumamoto AU - Suguru Katsube AU - Yuma Tsubaki AU - Hideaki Sato AU - Yuji Tsutsui AU - Kazuhiko Himuro AU - Shingo Baba AU - Masayuki Sasaki Y1 - 2021/05/01 UR - http://jnm.snmjournals.org/content/62/supplement_1/3042.abstract N2 - 3042Purpose: In PMT-based PET/CT systems, the continuous bed motion (CBM) method is inferior to the step-and-shoot (SS) method with regard to the background variations. SiPM-based PET/CT has been recently developed and has a higher photon-detection efficiency than PMT-PET/CT. This study evaluated the image quality of the CBM method in comparison with the SS method in a SiPM-PET/CT scanner.Materials and Methods: PET data were acquired using a Biograph Vision PET/CT scanner. In this study, data for 3 min/1 bed and 6 min/2 beds using the SS method and for a bed speed of 0.5-3.3 mm/sec using the CBM method were acquired. Images were obtained using a NEMA IEC Body Phantom Set with six spheres with a diameter of 10-37 mm filled with an 18F solution having a radioactivity ratio of 4:1 relative to the Background: A Gaussian filter was not used, the image matrix was 440 × 440, and the PET image slice thickness was 1.65 mm. Moreover, data were reconstructed using OSEM+PSF+TOF. This study evaluated the image quality using % contrast (QH, 10mm), % background variability (N10mm), contrast-noise ratio (QH, 10mm /N10mm), noise-equivalent count (NECphantom), and coefficient of variation of the background (CVbackground). These categories were assessed using PMOD 3.8. Furthermore, for visual assessment, the detectability of the hot spheres was evaluated using a 5-point scale (1, not absolutely visualized; 2, may not be visualized; 3, uncertain; 4, maybe visualized; and 5, absolutely visualized) by a board-certified nuclear medicine physician and two radiological technologists.Results: Regarding NEMA phantom images, QH, 10mm was 55.74%-61.75% and 50.39%-62.50% for the SS and CBM methods, respectively; the difference was insignificant. Additionally, N10mm was 5.89%-6.21% and 5.78%-16.69% for the SS and CBM methods, respectively; Q H, 10mm /N10mm was 9.08-9.59 and 3.06-10.38 for the SS and CBM methods, respectively. Moreover, CVbackground was 1.95%-2.01% and 1.80%-4.93% for the SS and CBM methods, respectively, and NECphantom was 14.67-21.27 Mcounts and 3.96-29.06 Mcounts for the SS and CBM methods, respectively. Furthermore, visual score of 10 mm sphere was 4.11-4.44 and 2.11-4.44 for the SS and CBM methods, respectively. No significant differences in any of the categories were observed between the SS (6 min/2 beds) and CBM (0.8 mm/sec) methods, whenever the acquisition time was almost equal.Conclusion: Upon using the same acquisition time in the entire body range, no differences in the detectability and image qualities in a SiPM-PET/CT scanner were observed between the SS and CBM methods. Based on these results, it could be concluded that the CBM method could replace the SS method because settings that are more detailed are possible in the former method. ER -