18F-FDG PET之最佳影像收集時間：用List Mode分析比較

Abstract

Background: 18F-FDG PET is performed in preset time model. Generally, the longer the acquisition time we set, the better the image quality we get. However, a prolonged acquisition time is associated with a decreased patient throughput and an increased risk of motion artifacts. In order to insure an acceptable image quality as well as a decreased acquisition time, we used list mode acquisition and statistic methods to find out an optimal acquisition time. Methods: Thirty 18F-FDG PET positive intra-abdominal lesions were acquired with list mode acquisition. ROIs were selected manually and SUV(subscript max) and SUV(subscript mean) were obtained. The ratios of SUVs in the lesion and background were calculated. We used Pearson's correlation coefficient, Kendall's tau-b correlation, and Spearman rho correlation to find the correlation between the resulted SUV ratios from different acquisition time of 0.5 to 9 min with what from 10 min. Then we used the paired t-test and nonparametric tests to find the optimal acquisition time. Results: As to the ratios of SUV(subscript max) of the lesions and background, there was significant difference in comparing those from acquisition time of 0.5 to 3 min with those from acquisition time of 10 min. If acquisition time was longer than 3 min, there was no significant difference. Conclusion: In 18F-FDG PET studies, acquisition time less than 3 min should be avoided.