ABSTRACT
OBJECTIVE: To analyze the relationship of the intima-media thickness( IMT) of carotid artery and accumulated radiation dose in intervention workers,and to evaluate the threshold dose leading to the abnormal IMT. METHODS: By cluster random sampling,155 intervention workers were selected as intervention group and 620 workers from the radiology departments were selected as control group. All workers came from 27 hospitals in Shandong Province. The workers in these two groups were given radiological occupational health check-up. Their accumulated dose of radiation was collected and IMT was measured by ultrasound. Multiple linear regression analysis was used to analyze the dose-effect between the IMT and the accumulated dose. RESULTS: In the intervention group,IMT was( 0. 70 ± 0. 11) mm,the abnormal rate of IMT was 4. 5%( 7 /155). The IMT in the control group was( 0. 68 ± 0. 09) mm,and the abnormal rate of IMT was 3. 9%( 24 /620). The abnormal rate of IMT between the two groups had no statistical significance( P > 0. 05). The multiple linear regression equation was y = 0. 007 x_1+ 0. 001 x_2- 0. 098 x3+ 0. 223( y means IMT,mm; x_1 means age,x_2 means accumulated radiation dose,mSv; x3 means gender),and the threshold doses deduced in all ages corresponding to 1 mm of IMT showed that the threshold dose was higher with younger age,and the larger accumulated radiation dose was needed to cause the IMT abnormity in the female than in the male workers. CONCLUSION: The IMT is positively correlated with the accumulated radiation dose in radiation workers,and the threshold dose of abnormal IMT could be estimated by the linear regression equation.