The relationship betweenBMI and striatal dopamine transporter with 99Tcm-TRODAT-1 brain SPECT

：Objective To assess therelationship between the BMI and the brain DAT, and the influence of BMI on the brainSPECT imaging with 99Tcm-TRODAT-1. Methods MRI and 99Tcm-TRODAT-1SPECT imaging wereperformed in 31 healthy volunteers(16 males and 15 females), and then thethree-dimensional reconstruction of SPECT images were completed. Based on the MRI images,right striatum (RST) and the left striatum (LST) were drawn as ROI on the 4 most clearlyconsecutive transverse slices.The cerebellum (CB) was taken as the background referencearea and the corresponding uptake ratios of ST/CB, LST/CB and RST/CB were calculated. ThePearson correlation tests for radio-uptake ratios (ST/CB, LST/CB, RST/CB), BMI and agewere performed, Then multiple linear regression analysis using ST/CB as dependent variableand BMI and age as independent variables was performed. SPSS 15.0 was used in dataanalysis. Results The ST imaging was symmetrical. The radioactivity was higher in the STfront area than that of the back area. The average uptake ratios of ST/CB, LST/CB, RST/CBwere 1.71±0.16,1.70 ± 0. 16 and 1.72±0.17 respectively, in which the three ratios ofthe female were 1.74 ± 0. 18, 1.71±0. 19 and 1.76 ± 0. 19 respectively and those of themale were 1.68 t 0. 14, 1.68 ± 0. 13 and 1.69± 0.15respectively. ST/CB, LST/CB andRST/CB were negatively correlated with patients'BMI (r = -0. 53,-0.57,-0.47, all P＜0.05).The ST/CB was negatively correlated with patients' age(r=-0.39, P=0. 03). The multiplelinear regression analysis showed that the BMI was significant independent variable (β=-0.53, t= -3.36, P=0. 002).Conclusions TheSTDAT,evel may decrease as patients' BMI and age increase. Females' DATlevel is slightly higher than males'. For ST DAT imaging, age, gender and BMI should beall taken into consideration. Key words: Brain;  Dopamine;  Body mass index;  Tomography,emission-computed, single-photon;  TRODAT-1