Objective: To examine the impact of acquisition time on Lutetium-177 ( 177 Lu) singlephoton emission computed tomography (SPECT) images using Monte Carlo simulation.Methods: A gamma camera simulation based on the Monte Carlo method was performed to produce SPECT images. The phantom was modeled on a NEMA IEC BODY phantom including six spheres as tumors. After the administration of 7.4 GBq of 177 Lu, radioactivity concentrations of the tumor/liver at 6, 24, and 72 h after administration were set to 1.85/0.201, 2.12/0.156, and 1.95/0.117 MBq/mL, respectively. In addition, the radioactivity concentrations of the tumor at 72 h after administration varied by 1/2, 1/4, coefficient (CRC) and contrast-to-noise ratio (CNR). In this study, the CNR threshold for detectability was assumed to be 5.0.Results: To compare collimators, the highest sensitivity was observed with ELEGP, followed by LEHR and MEGP-1. The highest ratio of direct ray was also observed in ELEGP followed by MEGP-1. In comparison of the radioactivity concentration ratios of tumor/liver, CRC and CNR were significantly decreased with smaller radioactivity concentration ratios. This effect was greater with larger spheres. According to the visual assessment, the acquisition time of 6, 6, and 3 min or longer was required using ELEGP collimator at 6, 24, and 72 h after administration, respectively. Physical assessment based on CNR and CRC also suggested that 6, 6, and 3 min or longer acquisition time was necessary at 6, 24, and 72 h after administration. Conclusion:177 Lu-SPECT images generated via the Monte Carlo simulation suggested that the recommended acquisition time was 6 min or longer at 6 and 24 h and 3 min or longer at 72 h after administration.
Background: SwiftScan (GE Healthcare) is a recently developed scanning technique with data acquisition during detector static and rotation. The influence of image quality using SwiftScan on quantitative bone single-photon emission computed tomography (SPECT) remains unclear. This study clarifies the effect of the acquisition time for SwiftScan on the image quality and quantification of bone SPECT compared to step and shoot mode (SSM) using 99mTc-filled anthropomorphic phantom (SIM2 bone phantom).Results: The coefficient of variance (CV), contrast-to-noise ratio (CNR), full width at half maximum (FWHM), and recovery coefficient (RC) of SwiftScan and SSM were recorded at various overall acquisition times (5, 7, 17, and 32 min) when the fixed reconstruction parameters (subsets 10 and iterations 5) were compared. The CV of SSM was higher than that of SwiftScan in short-time acquisition (less than 7 min), whereas the CV of SSM and SwiftScan are equivocal in long-time acquisition (more than 17 min). The CNR of SwiftScan was higher than that of SSM in short-time acquisition, whereas the CNR of SSM was equivocal or higher than that of SwiftScan in long-time acquisition. The FWHM of SSM (15.2–16.5 mm) and SwiftScan (15.4–15.9 mm) was almost constant when the acquisition time was 7 min or longer. However, SwiftScan (22.6 mm) and SSM (18.6 mm) showed high FWHM values at 5 min acquisition, deviating from the actual size (10 mm). For the RC of SwiftScan and SSM, was no evident difference between them was observed.Conclusions: SwiftScan on quantitative bone SPECT provides improved CV and CNR in short-time acquisition (less than 7 min) with quantitativeness similar to SSM. Therefore, using SwiftScan in clinical settings instead of the SSM scan protocol in short-time acquisition (less than 7 min) might provide higher quality diagnostic images than SSM. Our results would provide important information on the use of SwiftScan.
Background SwiftScan single-photon emission computed tomography (SPECT) is a recently released scanning technique with data acquired when the detector is stationary and when it moves from one view to the next. The influence of scan time for using SwiftScan on quantitative bone SPECT remains unclear. This study aimed to clarify the effect of the scan time for SwiftScan SPECT on the image quality and quantification of bone SPECT compared to step and shoot mode (SSM) using 99mTc-filled anthropomorphic phantom (SIM2 bone phantom). Materials and methods Phantom SPECT/computed tomography (CT) images were acquired using Discovery NM/CT 860 (GE Healthcare) with a low-energy high-resolution sensitivity collimator. We used the fixed parameters (subsets 10 and iterations 5) for reconstruction. The coefficient of variation (CV), contrast-to-noise ratio (CNR), full width at half maximum (FWHM), and quantitative value of SwiftScan SPECT and SSM were compared at various acquisition times (5, 7, 17, and 32 min). Results In the short-time scan (< 7 min), the CV and CNR of SwiftScan SPECT were better than those of SSM, whereas in the longtime scan (> 17 min), the CV and CNR of SwiftScan SPECT were similar to those of SSM. The FWHMs for SwiftScan SPECT (13.6–14.8 mm) and SSM (13.5–14.4 mm) were similar. The mean absolute errors of quantitative values at 5, 7, 17, and 32 min were 38.8, 38.4, 48.8, and 48.1, respectively, for SwiftScan SPECT and 41.8, 40.8%, 47.2, and 49.8, respectively, for SSM. Conclusions SwiftScan on quantitative bone SPECT provides improved image quality in the short-time scan with quantification similar to or better than SSM. Therefore, in clinical settings, using SwiftScan SPECT instead of the SSM scan protocol in the short-time scan might provide higher-quality diagnostic images than SSM. Our results could provide vital information on the use of SwiftScan SPECT.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.