Abstract：Objective The digital cadmium-zinc-telluride (CZT)-based single photon emission CT/CT system has advantages such as
good spatial and energy resolution. However, the impacts of different reconstruction parameters on CZT SPECT/CT quantification
need to be further verified. This study aimed to evaluate the impacts of reconstruction parameters (iterations, subsets in iterative
reconstruction, post-filter, and image correction methods) on the accuracy of technetium quantification of CZT
SPECT/CT. Methods A phantom (PET NEMA/IEC image quality) was filled with 32∶1 target-to-background (T/B) ratio of
technetium. The mean uptake values (the calculated mean concentrations for spheres) were measured to evaluate the changes of
recovery coefficient (RCs) under different reconstruction parameters. The image quality was evaluated using the National Electrical
Manufacturers Association (NEMA) NU 2-2012 standard. Results Significant correlations were found between iterations and RCs
(r=0.58~0.92 for 1~35 iterations, r=0.97~0.99 for 35~90 iterations) , as well as between the full width at half maximum (FWHM)
of the Gaussian filter and RCs (r=-0.87 to -1.00, P<0.05). In regression analysis, the regression coefficients of 1~35 iterations were
higher than those of 35~90 iterations (0.63~1.60 vs. 0.02~0.15). For all T/B ratios, the RCs calculated with attenuation correction
(AC) and scatter correction (SC) and resolution recovery correction (RR) combinations were more accurate than those calculated
with other combinations (67.80%~106.70%, P<0.05). Meanwhile, the combination of AC+SC+RR had the best visual image quality
and percent contrast (AC+SC+RR vs. AC+RR; AC+SC+RR vs. AC+SC, P<0.05). Conclusion The number of iterations has a great
impact on the absolute quantification, and smaller lesions need a larger number of iterations to improve the quantification accuracy.
Its influence is mainly within the first 35 iterations; the number of subsets has little influence on the absolute quantification and
RCs is not change significantly after 20 subsets; the FWHM value of the Gaussian filter has the greatest influence on absolute
quantification and RCs decreases significantly along with the increase of the FWHM value, and no plateau could be selected. The
image correction method has relatively a large impact on the absolute quantification and the combination of AC+SC+RR has both
closer quantification accuracy to the actual distribution and relatively better image quality. The CZT-SPECT/CT of technetium
results in good quantification accuracy. The favorable reconstruction parameters might be 35 iterations, 20 subsets, the AC+SC+RR
correction combination, and no filter.
王深，张如意，王澎，谭建，李宁，林晓云，孟召伟，贾强. 重建参数对于基于CZT半导体探测器SPECT/CT系统锝绝对定量准确性的影响[J]. 中国医疗设备, 2022, 37(10): 51-55.
WANG Shen, ZHANG Ruyi, WANG Peng, TAN Jian, LI Ning, LIN Xiaoyun, MENG Zhaowei, JIA Qiang. Impacts of Reconstruction Parameters on the Accuracy of Absolute Technetium Quantification
of the Cadmium-Zinc-Telluride-Based SPECT/CT System. China Medical Devices, 2022, 37(10): 51-55.
