Objective: To observe the uptake and metabolism of 18F-Fluorodeoxyglucose (¹⁸F-FDG) in various brain regions of the emotional regulationloop in generalized anxiety disorder (GAD) based on the PET,and the mechanism of brain dysfunction in GAD was studied. Methods: Dynamic PET-CT scanning was performed on 20 GAD patients and 20 healthy subjects. 18F-FDG whole-brain uptake and metabolism data were collected. SUV_max, dynamic uptake and metabolism changes of each brain structure at 11 time points in 150 mins were measured based on image fusion and semi-quantitative analysis. Results: Compared to the control group, there were less and slower uptake of ¹⁸F-FDG, faster metabolism in the bilateral prefrontal cortex in GAD group（P<0.05）.There were less, slower uptake of ¹⁸F-FDG and slower metabolism in the left striatum and left hippocampus in GAD group（P<0.05）. There were more, faster uptake of 18F-FDG and faster metabolism in the left thalamus in GAD group（P<0.05）.There were more and faster uptake of ¹⁸F-FDG in the right thalamus（P<0.05）, but no significant metabolism change in GAD group. The 3 indicators in right striatum and right hippocampus had no significant change in GAD group.Conclusion: There are ¹⁸F-FDG uptake and metabolism disorder of multiple brain structures of this loop in GAD, and its abnormal uptake peak, rate of uptake and rate of metabolism may be involved in the GAD.

［Key words］generalized anxiety disorder; emotional regulationloop; PET-CT; maximum standardized uptake value