Regional homogeneity and FDG uptake in patients with major depressive disorder

Objectives: To investigate changes in regional cerebral metabolic rates of glucose uptake (rCMRglc) and regional homogeneity (ReHo) in patients with major depressive disorder (MDD) using a multimodal neuroimaging approach with ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and resting-state blood oxygen level-dependent(Bold) functional magnetic resonance imaging (fMRI).

Methods: In total, 18 patients with untreated MDD and 17 healthy control subjects underwent both of Bold-fMRI and ^18F-FDG PET scanning. Changes in rCMRglc on ¹⁸F-FDG PET and regional homogeneity (ReHo) value on Bold-fMRI were analyzed in MDD patients.

Results: Compared with the control group, the MDD patients had a decreased rCMRglc in the bilateral superior, middle, and inferior frontal gyrus; bilateral superior and middle temporal gyrus; bilateral anterior cingulate cortex; bilateral putamen and caudate; and left pallidum but increased rCMRglc in the bilateral hippocampus and left thalamus. The ReHo values in the patient group were decreased in the bilateral superior and middle frontal gyrus, left pallidum, bilateral putamen, and left anterior cingulate cortex but increased in the right hippocampus and thalamus. There were no obvious statistical difference between the reducing metabolism an ReHo brain regions of MDD patients(χ².=9.16;p=0.90),the same as increasing metabolism an ReHo brain regions(χ².=3.96;p=0.27).

Conclusion: MDD patients have relatively characteristic change modes in brain glucose uptake and ReHo in a resting state.¹⁸F-FDG PET may find brain lesions of MDD patients more sensitively than Bold-fMRI. Research Support: The authors thank Weifeng Zhang, Huiqiang Li and Min Guan for the invaluable help in scanning patients and data analysis.