Objective:To compare the effects of different reconstruction algorithms on image quality and quantification in pulmonary nodule imaging using 18F-FDG PET/CT with Q. Flex technology. Methods:A retrospective cross-sectional analysis was conducted on 75 patients (40 males, 35 females; age 66(57, 72) years) with 112 pulmonary nodules who underwent 18F-FDG PET/CT at Tianjin Cancer Hospital Airport Hospital between May 2022 and August 2023. Images were reconstructed using ordered-subsets expectation maximization (OSEM)+ time of flight (TOF) (A1), OSEM+ TOF+ point spread function (PSF) (A2), and Q. Clear (A3) algorithms. Image quality was evaluated using visual scored (five-point scale) and signal-to-noise ratio(SNR). Quantitative parameters (SUV max and SUV mean of the lesions) were obtained. Lesions were stratified into small (≤10mm) and large (>10-30mm) subgroups based on the longest diameter. Statistical comparisons were performed using Kruskal-Wallis rank sum test with Bonferroni correction. Results:The A3 algorithm demonstrated higher SNR (30.68(20.16, 40.92)) and visual score sum (10(8, 10)) than A1(15.24(9.76, 23.60) and 6(6, 7)) and A2 (20.81(14.32, 30.70) and 8(6, 8)) ( H values: 72.38 and 176.40, both P<0.001; all adjusted P<0.001), with consistent findings in subgroup analyses ( H values: 33.86-110.26, all P<0.001; all adjusted P<0.001). SUV max (7.76(5.00, 10.08)) and SUV mean (4.93(3.93, 6.77)) were also significantly higher with A3 compared to A1 (5.70(4.12, 8.04) and 3.80(2.54, 5.20)) ( H values: 13.94 and 16.77, all adjusted P<0.001). Subgroup analysis revealed that in small nodules(≤10mm), the A3 algorithm provided the most significant improvement in image quality and quantitative parameters ( H values: 9.89-36.34, all P<0.001), while no statistically significant differences were observed among algorithms in large nodules(>10-30mm) regarding quantitative parameters ( H values: 2.03-4.95, all P>0.05). Conclusion:In 18F-FDG PET/CT using Q. Flex technology, the Q. Clear algorithm significantly improves image quality, SNR, and quantitative results, particular for small pulmonary nodules.
(8.0+极速模式)