首发抑郁症患者杏仁核及海马^18F-FDG摄取及代谢过程的PET／CT动态研究

^18F-FDG uptake and clearance in the amygdala and hippocampus in patients with first-episode depression

目的通过PET/CT动态观察首发抑郁症患者杏仁核及海马的^18F－FDG摄取及代谢变化规律，探讨抑郁症相关神经生物学机制。方法对2014年1月至2016年1月的35例首发抑郁症门诊患者及35例健康志愿者静脉注射^18F－FDG，经PET/CT采集多个时间点杏仁核及海马的^18F－FDG摄取数据，测SUVmax并计算代谢清除率。采用两样本t检验比较组间不同时间点的摄取和代谢清除率。结果相较于健康组，首发抑郁组的左侧杏仁核摄取峰值提前，SUVmax分别为注射显像剂后40 min的10.50±1.79和25 min的12.94±2.03，10、25、40、55、70、85 min 2组间摄取差异均有统计学意义（t值：12.92、8.65、6.99、12.34、28.87、13.87，均P〈0.05）；代谢率明显加快，40～55 min，56～70 min，71～85 min的代谢率差异有统计学意义（t值：32.53、32.73、11.10，均P〈0.05）。首发抑郁组的左侧海马摄取减低、代谢率明显减慢，10～85 min中5个时间点（除70 min）2组摄取差异有统计学意义（t值：2.70、7.75、7.78、8.81、7.00，均P〈0.05），40～55 min，56～70 min，71～85 min 3个时间段代谢率差异有统计学意义（t值：6.02、62.15、37.39，均P〈0.05）。2组右侧杏仁核及右侧海马摄取与代谢变化结果无明显差异。结论抑郁症患者存在杏仁核及海马的^18F－FDG摄取及代谢障碍，表现为左侧杏仁核摄取峰值提前、代谢增快及左侧海马摄取能力下降、代谢减缓。

ObjectiveTo observe the dynamic changes of ^18F-FDG uptake and clearance in the amygdala and hippocampus in patients with first-episode depression（FED）, and explore the neurobiology mechanism of FED.Methods^18F-FDG PET/CT imaging was performed on 35 patients with FED and 35 healthy volunteers from January 2014 to January 2016. SUVmax in the amygdala and hippocampus at different time points were collected. The clearance rates were calculated and the difference between patients and healthy volunteers were compared by two-sample t test.ResultsThe FDG uptake in the left amygdala of patients reached the peak earlier compared with that in the healthy group, with the SUVmax of 12.94±2.03 at 25 min and 10.50±1.79 at 40 min, respectively. FDG uptake in the left amygdala at 10, 25, 40, 55, 70, 85 min between the 2 groups were significantly different （t values： 12.92, 8.65, 6.99, 12.34, 28.87, 13.87; all P〈0.05）. The clearance rate in the left amygdala of patients at different time interval was increased compared with that of the healthy group（40-55 min： t=32.53; 56-70 min： t=32.73; 71-85 min： t=11.10; all P〈0.05）. Compared with the healthy group, FDG uptake in the left hippocampus of patients was decreased significantly at 10, 25, 40, 55, 85 min （t values： 2.70, 7.75, 7.78, 8.81, 7.00; all P〈0.05） for FDG uptake, and the clearance rate was also decreased significantly at different time interval（40-55 min： t=6.02; 56-70 min： t=62.15; 71-85 min： t=37.39; all P〈0.05）. Differences of metabolic changes in the right amygdala and the right hippocampus were not significant.Conclusions^18F-FDG metabolism in the amygdala and hippocampus of patients with FED may be abnormal, which is characterized by earlier peak uptake and quicker clearance in the left amygdala while lower uptake and slower clearance in the left hippocampus.