Nuklearmedizin 2020; 59(02): 148
DOI: 10.1055/s-0040-1708305
Wissenschaftliche Poster
Medizinische Physik II
© Georg Thieme Verlag KG Stuttgart · New York

GATE Monte Carlo simulation model of the Symbia Intevo SPECT/CT system

H Kertesz
1   QIMP Team, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna
,
N Denisova
2   Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch of Russian Academy of Sciences, Novosibirsk
,
M Ondar
3   Novosibirsk State Technical University, Novosibirsk
,
J Cal-Gonzalez
1   QIMP Team, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna
,
I Rausch
1   QIMP Team, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna
,
P Schaffarich
1   QIMP Team, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna
,
T Beyer
1   QIMP Team, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna
› Author Affiliations
Further Information

Publication History

Publication Date:
08 April 2020 (online)

Also available ateRef
 
 

    Ziel/Aim To model and evaluate the performance of a state-of-the-art SPECT(/CT) system (Siemens Symbia Intevo) using GATE simulations as part of an ongoing project for the validation of a novel image reconstruction algorithm using local regularization (MAP-L).

    Methodik/Methods The SPECT system is made of two NaI-based detector heads (59.1x44.5x0.95cm3). The useful field-of-view (UFOV) is 53.3 × 38.7cm. Low-energy high-resolution (LEHR) collimator was modelled, which is made of lead with hexagonal holes (diameter of 1.11mm, height 24.05mm, septal thickness 0.16mm). The SPECT model was evaluated following the NEMA NU1-2007 protocol for system planar sensitivity (SPS) and intrinsic spatial resolution (ISR). For the evaluation of the SPS a Petri dish (diameter 150mm, height 15mm) filled with 125MBq 99mTc was used. The evaluation of the ISR was done with the NEMA X-Y phantom made of a 3mm thick lead plate with 1mm slits positioned at a distance of 30mm. A point source (1GBq activity 99mTc) was placed in a lead shielded holder at a distance of 270 cm from the detector. The full-with half-maximum (FWHM) and full-width tenth-maximum (FWTM) were calculated for the UFOV and the central field-of-view (CFOV). The simulated values were compared to the measured reference values that were obtained previously during the acceptance test of the system. The ISR in Y direction was not reported in the acceptance test.

    Ergebnisse/Results The simulated (measured) SPS with the LEHR collimator at 10cm distance was 92.8(88.7) cps/MBq and 93.8(89.0) cps/MBq for detector 1 and 2, respectively. The ISR in X direction was 3.3mm (3.5mm) FWHM for both UFOV and CFOV, 6.3(6.8mm) FWTM for UFOV and 6.4 (6.8mm) FWTM for CFOV. In Y direction the simulated ISR was 3.1mm FWHM and 6.1mm FWTM for both UFOV and CFOV.

    Schlussfolgerungen/Conclusions The proposed SPECT model shows good accuracy with less than 6 % deviation from the measured reference values. The model will be extended and validated with the high-energy collimator for 131Isimulations and will be made available online.