18F-FDG PET/CT心肌代谢显像受检者的周围辐射剂量水平

目的 探索PET/CT心肌代谢显像受检者周围辐射剂量水平，为保证周围人员辐射安全提供数据支持。方法 选取33例行¹⁸F-FDG PET/CT心肌代谢显像患者，在受检者胸部等高位置按照不同体位方向、时间和距离处对其周围剂量当量率进行测量，探索受检者周围剂量当量率的分布规律。结果 在相同测量时间和距离下，受检者身体两侧的周围剂量当量率相比正、背面更低。受检者注射¹⁸F-FDG显像剂后，距离体表1 m处正面的周围剂量当量率为13～21 μSv/h，检查结束后降至5～14 μSv/h，平均降低46%。受检者周围剂量当量率随距离（10～300 cm）的增加呈幂函数趋势降低，其幂指数均值为?1.2。结论 心肌代谢显像受检者注射药物后周围辐射水平较高，周围剂量当量率随时间和距离增加快速降低，建议心肌代谢显像受检者检查当天避免与他人长时间、近距离接触。

Ambient radiation of patients undergoing 18F-FDG PET/CT myocardial metabolism imaging

Objective To study the ambient radiation of patients undergoing ¹⁸F-FDG PET/CT myocardial metabolism imaging, and to provide data for protection of surrounding people against radiation.Methods A total of 33 patients were selected for ¹⁸F-FDG PET/CT myocardial metabolism imaging. Dose equivalent rate was measured at the height of patient chest, in different directions, at different time points and at different distances, to investigate the distribution of ambient radiation of the patient.Results At the same time point and distance, the dose equivalent rates at the left and right sides of the patient were lower than the front and back sides. The dose equivalent rate at 1 m in front of the patient was 13-21 μSv/h after ¹⁸F-FDG injection, and decreased to 5-14 μSv/h after PET/CT imaging, with a mean decrease of 46%. The ambient dose equivalent rate decreased exponentially with distance (10~300 cm), and the mean power was -1.2.Conclusion The ambient radiation of patients undergoing ¹⁸F-FDG PET/CT myocardial metabolism imaging was high after ¹⁸F-FDG injection, and the ambient dose equivalent rate decreased rapidly with time and distance. Our results suggest that patients undergoing myocardial metabolism imaging should avoid prolonged and close contact with other people on the day of examination.