Study on impact of source distance changes on the intrinsic spatial resolution and linearity of single photon emission computed tomography equipment
10.3760/cma.j.cn112271-20240119-00025
- VernacularTitle:源距变化对单光子发射计算机断层成像设备固有空间分辨力和固有空间线性影响的研究
- Author:
Hao HONG
1
;
Jianhua GENG
1
;
Zhiwen CHEN
1
;
Xuesong SU
1
;
Xuejuan WANG
1
;
Jing LI
1
Author Information
1. 国家癌症中心 国家肿瘤临床医学研究中心 中国医学科学院北京协和医学院肿瘤医院核医学科，北京 100021
- Publication Type:Journal Article
- Keywords:
Source distance;
Parallel slit lead grid phantom;
Intrinsic spatial resolution;
Intrinsic spatial linearity
- From:
Chinese Journal of Radiological Medicine and Protection
2024;44(12):1049-1055
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study the impact of changes in distance from the point source to the detector lead grid phantom surface on the intrinsic spatial resolution and linearity of single photon emission computed tomography equipment (SPECT), and to provide references for exploring quality control performance testing method.Methods:The intrinsic spatial resolution and linearity indexes of the dual detectors of the two SPECT machines(model 1, 2) were examined using the parallel slit lead grid phantom method, respectively, at five different positions of the vertical distance from the point source to the surface of the lead grid phantom, namely, 150, 170, 190, 210 and 230 cm.Results:After completion of image acquisition about the two SPECT machines with dual detectors at the five positions, the software-based calculated intrinsic spatial resolution and linearity in x and y direction fluctuated both within a very small range: effective field of view half-width half-maximum 3.310-3.902 mm, central field of view half-width half-maximum 3.274-3.910 mm, UFOV differential linearity (0.059-0.180 mm), FUOV absolute linearity (0.171-0.628 mm), CFOV differential linearity (0.046-0.165 mm), CFOV absolute linearity (0.115-0.534 mm). The intrinsic spatial resolution was slightly poor at a source distance of 150 cm. The UFOV FWHM detection value of two machines was (3.80±0.07)mm, with a range of 3.695-3.902 mm. The CFOV FWHM detection value was (3.73±0.11) mm, with a range of 3.572-3.910 mm. However, no statistically significant difference was found in inherent spatial resolution between model 1 and model 2 ( P>0.05). Under the WS 523-2019, the intrinsic spatial resolution and linearity of two machines with dual detectors were both qualified. The comparison of inherent spatial linearity between model 1 and model 2 showed that model 1 was inferior to model 2, with statistically significant difference ( t=15.09, P<0.001). Conclusions:There was no variation in intrinsic spatial resolution and linearity with the source distance when the vertical distance from the point source to the surface of the detector lead grid phantom was changed (150 to 230 cm). When intrinsic spatial resolution and linearity testing were performed on SPECT, it is necessary to ensure that the vertical distance from the point source to the detector is greater than 150 cm and recommended to be at least 170 cm.
