Clinical Value Of Semi-quantitative Analysis Of ～(18)F-FDG Cerebral Metabolism PET In Patients With Parkinson's Disease

[Objective]To discuss the clinical diagnostic value of 18F-FDG cerebral glucose metabolism PET in patients with parkinsonian features through semi-quantitative analysis of metabolic function of the striatum structures. [Methods]162 cases underwent 18F-FDG cerebral glucose metabolism PET were grouped into Parkinson's disease (PD)(62 cases) and age-matched healthy control (100 cases). Patients with PD were divided into three groups by Hoehn and Yahr stages criterion: stage I (n=20), stage II (n=26) and stage II (n=16). The standard uptake values (SUV) of the caudate nucleus, pulamen and cerebellum were calculated by semi-quantitative region of interest (ROI) and the ratios of target/cerebellum. The ratios were regarded as the index of striatum's function. [Results]1. In the healthy control group, there was no linear correlation between the means of SUV semi-quantitative ratios and ages (caudatenucleus/cerebellum: r=0.04, P>0.05, n=100; putamen/cerebellum: r=0.04, P>0.05, n=100). The means of SUV semi-quantitative ratios of both sides of striatum with the caudate nucleus/cerebellum were 1.61 + 0.23 (Left), 1.62 0.23 (Right), putamen/cerebellum were 1.67 0.21 (Left), 1.67 + 0.21 (Right) , respectively. There were no significant differences between each side of caudate nucleus and putamen (P>0.05).2. On qualitative visual analysis, the characteristic 18F-FDG PET images of PD patients demonstrated abnormal distribution of radioactivity in striatum (caudate and putamen), cerebral lobes or cerebellum in 95.2%(59/62) of the PD cases. Among them 88.7%(55/62) showed asymmetrical hypometabolism in the striatum, and the putamen was marked decrease.3. According to the semi-quantitative analysis, the semi-quantitative ratios of striatum of patients with PD were lower than those of healthy volunteers (1.26 + 0.19 for caudate nucleus/cerebellum, 1.40 + 0.13 for putamen/cerebellum). Their semi-quantitative ratios of caudate nucleus and putamen, which were contraleral to the affected limb (or first affected limb), were lower than those of ipsilateral (f=8.96, 11.26; P<0.01). There were significant differences in different Hoehn and Yahr stages (FBetween=51.78, P<0.01), and this result was closely relative to the clinical characteristic of PD.[Conclusions]The method of semi-quantitative analysis of striatum functions is more likely to diagnose PD earlier and help to determine its clinical stage.