Objective To investigate the characteristics of ¹¹C-2-carbomethoxy-3-(4-fluorophenyl) tropane (¹¹C-CFT) brain dopamine transporter (DAT) PET/CT imaging and analyze its clinical diagnostic value in patients with Parkinson's disease (PD).

Methods A retrospective analysis was performed on the clinical and images data of 41 patients with primary PD who underwent ¹¹C-CFT PET/CT brain imaging in the Affiliated Hospital of Guizhou Medical University from August 2018 to February 2021. The patients included 21 males and 20 females aged 34–81(57.6±12.2) years. The patients were divided into early PD group (19 cases) and late PD group (22 cases) according to the Hoehn and Yahr (H-Y) grade. Moreover, eight healthy subjects matched with the PD group were included as the normal control group. The subjects including 4 males and 4 females aged 42–72 (61.0±9.8) years. The ¹¹C-CFT uptake values of the bilateral caudate nucleus, putamen, and cerebellum were obtained by delineating the regions of interest. The ¹¹C-CFT uptake values of the bilateral caudate nucleus, putamen, and new striatum; the asymmetry index and the ratio of the putamen to the caudate nucleus were calculated according to the corresponding formula. Two independent sample t-test was used to compare the measurement data. Chi square test was used to compare counting data, and Pearson correlation analysis was used to evaluate the correlation between DAT distribution in the new striatum and subareas of PD patients and clinical indicators.

Results In ¹¹C-CFT PET/CT brain imaging, the radioactivity distribution of the bilateral caudate nucleus in the PD group was slightly reduced but still uniform, and the radioactivity distribution of the bilateral putamen nucleus in the PD group was reduced or sparse. The radiation distribution of the bilateral putamen was asymmetrically reduced or defective in the early PD group and symmetrical and sparse in the late PD group. Compared with the normal control group, the ¹¹C-CFT value of the new striatum in the PD group was significantly decreased, and the difference was statistically significant (12.29±2.75 vs.7.69±2.42, t=4.818, P<0.01). The asymmetry index increased in the PD group and was most obvious in the putamen, and the difference was statistically significant (0.06±0.08 vs. 0.14±0.09, t=2.184, P<0.05). The ratio of the ¹¹C-CFT uptake value in the putamen to that in the caudate nucleus decreased in the PD group, and the difference was statistically significant (1.13±0.13 vs. 0.74±0.21, t=4.929, P<0.01). Compared with the early PD group, the late PD group had the most significant decrease in ¹¹C-CFT uptake in the new striatum, and the difference was statistically significant(8.50±1.77 vs. 6.99±2.71, t=2.070, P<0.05). Significant differences were found in the asymmetry indexes between the caudate nucleus and putamen in the early PD group and the late PD group, and the differences were statistically significant (0.06±0.06 vs. 0.11±0.08, 0.18±0.10 vs. 0.11±0.07; t=2.251, 2.858; both P<0.05). In the PD patients, the ¹¹C-CFT uptake index in the new striatum was negatively correlated with age, onset age, and H-Y grade (r=−0.444, −0.514, −0.426; all P<0.01), and positively correlated with the asymmetry index of ¹¹C-CFT uptake in putamen (r=0.331, P<0.05). The ¹¹C-CFT values of the caudate nucleus in the PD patients were negatively correlated with age, onset age, and H-Y grade (r=−0.537, −0.581, −0.380; all P<0.05) but positively correlated with the putamen asymmetry index (r=0.410, P<0.01). In the PD patients, the putamen ¹¹C-CFT was negatively correlated with the onset age and H-Y grade (r=−0.353, −0.453; both P<0.05) and positively correlated with the course of disease and the ratio of the putamen to the caudate nucleus (r=0.322, 0.396; both P<0.05).

Conclusions In ¹¹C-CFT PET/CT brain DAT imaging, the patients with PD showed decreased radioactivity distribution in the bilateral caudate nucleus and putamen. ¹¹C-CFT PET/CT brain DAT imaging is helpful for PD diagnosis and severity assessment.