背景：18F-FDG (FDG) PET影像收集是以預設時間模式進行，雖然一般共識爲影像收集時間越長，品質越好，但是過長的收集時閒除了會減少檢查的流量，也會增加受檢者的不適及受檢者在檢查中因移動造成影像誤差的風險。爲確保影像品質，同時減少檢查時間，利用list mode及統計的方式找出臨床應用上可接受、無顯著差異性的理想收集時間爲此研究的最大目的。方法，本研究針對30個腹部病灶進行list mode的FDG PET，透過人工方式圈選ROI，得到最大及平均SUV值後，再將其病灶與背景SUV的比值經由Pearson相關、Kendall's tau-b統計量數及Spearman's rho係數三種相關係數檢定中求取影像收集時间爲0.5~9分鐘與收集時間爲10分鐘之間的相關性。而後運用SPSS之成對樣本T檢定及無母數之兩個相關樣本檢定兩種統計方式，找出具有統計意義的理想收集時間。結果：以病灶與背景的最大SUV值的比值而言，收集時間爲0.5~3分鐘和收集時間爲10分鐘相比具顯著差異性；三分鐘以上則不具顯著差異性。結論：FDG PET造影應避免使用三分鐘以下的收集時間。

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.