腦部FDG正子造影最佳起始時間：比較灰白質的放射計數比值

Optimal Initiating Time for Cerebral Fdg Pet Scan: Comparison Using Gray and White Matter Radioactivity Count

孫辰明(Chen-Ming Sun) ； 周國梁(Kuo-Liang Chou) ； 瘳澍昆(Shu-Quinn Liao) ； 劉仁賢(Ren-Shyan Liu)

《核子醫學雜誌》 13卷4期 (2000/12) Pp. 209-215

摘要

Background: To determine the optimal scanning time for cerebral FDG PET scan, we compared 4 sequential 30-minute images using gray and white matter radioactivity ratio. Methods: Emission scan was started immediately after injection of 10 mCi of 18F-FDG and lasted for 120 minutes in5 healthy volunteer. The 120 minutes acquisition data were divided into four 30-minute images, Scan 1:image from0 to 30 minute, Scan 2:image from 31 to 60 minute, Scan 3:image from 61 to 90 minute, and Scan 4:image from91 to 120 minute. Regions of interest(ROIs)were generated from 2 transverse slices which showed most prominent basal ganglia in each subject. We manually draw ROIs in gray matter of bilateral frontal, superior temporal and occipital lobes, and white matter of bilateral frontal lobes. The gray and white matter radioactivity ratio was expressed as average radioactivity count of gray matter ROIs/average radioactivity count of white matter ROIs. Results: The ratios of mean gray/white matter radioactivity were between 1.68 and 1.91.There was statistically significant difference(P＜0.0001)between the 4 scans by repeated measures ANOVA. Multiple paired t-test showed no difference between Scan 1 and Scan 2(P=0.305),and between Scan 3 and Scan 4 either(P=0.209).However, there are significant differences between Scan 1 and Scan 3(P=0.005),Scan 1 and Scan 4(P=0.002),Scan 2 and Scan 3(P=0.000),Scan 2 and Scan 4(P=0.000).Conclusion: Our preliminary result showed that delayed initiating time could have better image quality, and the image acquired from earlier initiating time showed no difference in comparison with ordinary initiating time. There fore, we can arrange the time to start image acquisition earlier and more flexibly.

關鍵字

正子造影 ； 超始時間 ； 灰質 ； 白質 ； 放射計數比值

並列摘要

Background: To determine the optimal scanning time for cerebral FDG PET scan, we compared 4 sequential 30-minute images using gray and white matter radioactivity ratio. Methods: Emission scan was started immediately after injection of 10 mCi of 18F-FDG and lasted for 120 minutes in5 healthy volunteer. The 120 minutes acquisition data were divided into four 30-minute images, Scan 1:image from0 to 30 minute, Scan 2:image from 31 to 60 minute, Scan 3:image from 61 to 90 minute, and Scan 4:image from91 to 120 minute. Regions of interest(ROIs)were generated from 2 transverse slices which showed most prominent basal ganglia in each subject. We manually draw ROIs in gray matter of bilateral frontal, superior temporal and occipital lobes, and white matter of bilateral frontal lobes. The gray and white matter radioactivity ratio was expressed as average radioactivity count of gray matter ROIs/average radioactivity count of white matter ROIs. Results: The ratios of mean gray/white matter radioactivity were between 1.68 and 1.91.There was statistically significant difference(P＜0.0001)between the 4 scans by repeated measures ANOVA. Multiple paired t-test showed no difference between Scan 1 and Scan 2(P=0.305),and between Scan 3 and Scan 4 either(P=0.209).However, there are significant differences between Scan 1 and Scan 3(P=0.005),Scan 1 and Scan 4(P=0.002),Scan 2 and Scan 3(P=0.000),Scan 2 and Scan 4(P=0.000).Conclusion: Our preliminary result showed that delayed initiating time could have better image quality, and the image acquired from earlier initiating time showed no difference in comparison with ordinary initiating time. There fore, we can arrange the time to start image acquisition earlier and more flexibly.

並列關鍵字

PET ； initiating time ； gray matter ； white matter ； radioactivity ratio