Performance evaluation of fifth-generation ultra-high-resolution SPECT system with two stationary detectors and multi-pinhole imaging

EJNMMI Physics

Takayuki Kanno¹  Jan-Peter Grunz²  Andreas K. Buck³  Jan P. Janssen⁴  Jan V. Hoffmann⁴  Takahiro Higuchi⁵  Takayuki Shibutani⁶  Masahisa Onoguchi⁶  Constantin Lapa⁷ 

[1] Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany;Department of Quantum Medical Technology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan;Department of Diagnostic and Interventional Radiology, University Hospital Würzburg, Würzburg, Germany;Department of Nuclear Medicine, University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080, Würzburg, Germany;Department of Nuclear Medicine, University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080, Würzburg, Germany;Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany;Department of Nuclear Medicine, University Hospital Würzburg, Oberdürrbacher Strasse 6, 97080, Würzburg, Germany;Comprehensive Heart Failure Center, University Hospital Würzburg, Würzburg, Germany;Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan;Department of Quantum Medical Technology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan;Nuclear Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany;

关键词: Small-animal imaging, SPECT;    Mouse;    Collimator;    Post-reconstruction filtering;   

DOI  :  10.1186/s40658-020-00335-6

来源: Springer

【 摘 要 】

BackgroundSmall-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT+).MethodsThe new U-SPECT5-E with two stationary detectors was used for acquiring data with 99mTc-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT+ for comparison.ResultsPeak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT+. In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT+) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR.ConclusionsWhile uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup.

【 授权许可】

CC BY