Verification of Effect of Acquisition Time for SwiftScan on Quantitative Bone Single-Photon Emission Computed Tomography Using an Anthropomorphic Phantom

Abstract

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.