人体水循环对正电子发射断层扫描检查后患者周围环境辐射衰减的影响分析

Analysis on the effect of water circulation of human body on radiation attenuation of surrounding environmental of patients post PET examination

目的:探讨人体水循环对正电子发射断层扫描(PET)检查后患者周围环境辐射衰减的影响,指导临床PET检查患者的辐射安全。方法:选择在医院进行PET检查的40例患者,将其按数表法随机分为对照组和观察组,每组20例。对照组患者检查结束后正常饮水、排尿;观察组患者检查结束后设定在注射药物后2 h、3 h和4 h内分别匀速饮水1000 ml,共计3000 ml,有尿意后排尿,用高灵敏度环境辐射监测仪测量两组患者在规定时间点、规定距离范围的辐射剂量率,并对数据进行分析。结果:两组患者1 m距离点的辐射剂量随时间衰减曲线均符合指数衰减规律。指数系数对照组为0.37,观察组为0.39,对照组患者在静脉注射完18F-FDG后1 h、2 h、4 h及8 h时周围1 m距离辐射剂量率分别为(12.57±0.39)μGy/h、(8.57±0.27)μGy/h、(3.92±0.30)μGy/h和(0.95±0.07)μGy/h;观察组为(12.9±0.31)μGy/h、(8.62±0.30)μGy/h、(3.65±0.24)μGy/h和(0.83±0.07)μGy/h,两组患者辐射衰减指数系数以及相同时间点、相同距离范围辐射剂量率无统计学差异。结论:患者PET检查后嘱其多喝水、多排尿,并不利于检查后患者对周围环境辐射的衰减。

Objective:To investigate the effect of water circulation of human body on radiation attenuation of surrounding environmental of patients post positron-emission tomography(PET)examination so as to guide the radiation safety of patients who underwent clinical PET examination.Methods:40 patients who underwent PET examination in hospital were randomly divided into control group(n=20 cases)and observation group(n=20 cases)according to the number table method.Patients of control group drank water and urinated normally after the examination.After the examination,patients of observation group were arranged to drink 1000 ml of water as constant speed at 2 h,3 h and 4 h after the examinations were completed,respectively,and a total of 3000 ml were each patient drank.And they urinated after they had micturition desire.The environmental radiation monitor with high-sensitivity was used to measure radiation dose rates of the patients of two groups at stipulated time point and stipulated distance range,and these data were further analyzed.Results:The attenuation curves of radiation dose with time both two groups accorded with the rule of exponential attenuation at 1 m distance point.And the index coefficients of control group and observation group were 0.37 and 0.39,respectively.After 18 F-FDG was implemented intravenous injection,the radiation dose rates of patients of control groups around 1 m distance point at 1 h,2 h,4 h and 8 h were(12.57±0.39)μGy/h,(8.57±0.27)μGy/h,(3.92±0.30)μGy/h and(0.95±0.07)μGy/h,respectively.And those of observation group were(12.9±0.31)μGy/h,(8.62±0.30)μGy/h,(3.65±0.24)μGy/h and(0.83±0.07)μGy/h,respectively.There was no significant difference in the radiation attenuation index coefficients,and the radiation dose rates at the same time point and same distance between the two groups.Conclusion:The guidance that patients are instructed to drink more water and urinate more after they undergo PET examination is not conducive to the attenuation of radiation in the surrounding environment of patients.