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目的通过测量移动CT与普通CT扫描所致受检者敏感器官(眼晶体、甲状腺、胸腺、乳腺、小肠、性腺)体表皮肤入射处空气比释动能及辐射场分布情况,了解移动CT和普通CT扫描各自剂量特点,为合理应用及采取防护措施提供科学依据。方法用热释光剂量计(TLD)测量CT受检者六个敏感器官体表剂量和周围环境剂量。结果移动CT扫描致受检者剂量具有新特点,头部扫描眼晶体体表剂量平均为66.6mGy,转换为脑部吸收剂量约为61.62mGy,是普通CT的2.8倍,也高于头部CT扫描的医疗照射指导水平50mGy;邻近投照部位的甲状腺和胸腺处剂量高于普通CT,而乳腺、小肠、性腺和周围环境的剂量低于普通CT。加防护后,相应部位的剂量明显降低。结论应按照移动CT的特性及功能,合理应用,并注重受检者非投照部位的防护。
Objective To investigate the distribution of air kerma and radiation field in the skin at the skin surface of sensitive subjects (eye lens, thyroid, thyroid, breast, small intestine and gonad) caused by moving CT and plain CT scan, CT scan the respective dose characteristics, to provide a scientific basis for the rational application and take protective measures. Methods TLD was used to measure body surface dose and ambient dose of six sensitive organs of CT subjects. Results There was a new characteristic in the dose of CT scanning. The average dosage of CT scan in the head scan eye was 66.6 mGy, and the dose absorbed in the brain was about 61.62 mGy, which was 2.8 times higher than that of CT and higher than that of CT The scanning level of medical exposure was 50 mGy. The dosage of thyroid and thymus adjacent to the site of irradiation was higher than that of normal CT, while the dose of mammary gland, small intestine, gonads and surrounding environment was lower than that of normal CT. Add protection, the corresponding part of the dose was significantly reduced. Conclusions should be in accordance with the characteristics and functions of mobile CT, reasonable application, and pay attention to the subject non-projection site protection.