Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow com...Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow computational speed.Progress in heterogeneous computing has allowed for substantial acceleration in the computation of mesh-type phantoms by utilizing hardware accelerators.In this study,a GPU-accelerated Monte Carlo method was developed to expedite the dose calculation for mesh-type computational phantoms.This involved designing and implementing the entire procedural flow of a GPUaccelerated Monte Carlo program.We employed acceleration structures to process the mesh-type phantom,optimized the traversal methodology,and achieved a flattened structure to overcome the limitations of GPU stack depths.Particle transport methods were realized within the mesh-type phantom,encompassing particle location and intersection techniques.In response to typical external irradiation scenarios,we utilized Geant4 along with the GPU program and its CPU serial code for dose calculations,assessing both computational accuracy and efficiency.In comparison with the benchmark simulated using Geant4 on the CPU using one thread,the relative differences in the organ dose calculated by the GPU program predominantly lay within a margin of 5%,whereas the computational time was reduced by a factor ranging from 120 to 2700.To the best of our knowledge,this study achieved a GPU-accelerated dose calculation method for mesh-type phantoms for the first time,reducing the computational time from hours to seconds per simulation of ten million particles and offering a swift and precise Monte Carlo method for dose calculation in mesh-type computational phantoms.展开更多
目的:调查北京大兴区人民医院各台CT设备的辐射剂量水平和典型值,为提升辐射风险防范最优化提供依据。方法:回顾性分析2023年7月至12月5台CT设备头颅、胸部、腹部检查的扫描参数及辐射剂量数据,确定其典型值(中位数),并与国内外的诊断...目的:调查北京大兴区人民医院各台CT设备的辐射剂量水平和典型值,为提升辐射风险防范最优化提供依据。方法:回顾性分析2023年7月至12月5台CT设备头颅、胸部、腹部检查的扫描参数及辐射剂量数据,确定其典型值(中位数),并与国内外的诊断参考水平(DRL)进行比较。结果:本次调查头颅、胸部、腹部的容积CT剂量指数(CTDI_(vol))、剂量长度乘积(DLP)典型值分别为54.40 m Gy,735.80 m Gy·cm;14.20 m Gy,443.60 m Gy·cm;16.40 m Gy,678.20 m Gy·cm。头颅的CTDI_(vol)、DLP典型值最高,腹部次之,胸部最低。头颅CTDI_(vol)及DLP存在随年龄增加而略增大趋势。不同使用年限CT设备的头颅、腹部CTDI_(vol)、DLP存在显著性统计学差异。本次调查各部位DLP较其他国家偏低。除了头颅DLP稍偏大,其余辐射剂量均低于国家卫生行业标准。腹部DLP较其他省市偏大。结论:本次调查成人CT辐射剂量与国内外结果基本一致,需要对CT检查的扫描范围进行规范化培训和优化,以减少受检者不必要的辐射暴露。展开更多
基金supported by the National Natural Science Foundation of China(Nos.U2167209 and 12375312)Open-end Fund Projects of China Institute for Radiation Protection Scientific Research Platform(CIRP-HYYFZH-2023ZD001).
文摘Computational phantoms play an essential role in radiation dosimetry and health physics.Although mesh-type phantoms offer a high resolution and adjustability,their use in dose calculations is limited by their slow computational speed.Progress in heterogeneous computing has allowed for substantial acceleration in the computation of mesh-type phantoms by utilizing hardware accelerators.In this study,a GPU-accelerated Monte Carlo method was developed to expedite the dose calculation for mesh-type computational phantoms.This involved designing and implementing the entire procedural flow of a GPUaccelerated Monte Carlo program.We employed acceleration structures to process the mesh-type phantom,optimized the traversal methodology,and achieved a flattened structure to overcome the limitations of GPU stack depths.Particle transport methods were realized within the mesh-type phantom,encompassing particle location and intersection techniques.In response to typical external irradiation scenarios,we utilized Geant4 along with the GPU program and its CPU serial code for dose calculations,assessing both computational accuracy and efficiency.In comparison with the benchmark simulated using Geant4 on the CPU using one thread,the relative differences in the organ dose calculated by the GPU program predominantly lay within a margin of 5%,whereas the computational time was reduced by a factor ranging from 120 to 2700.To the best of our knowledge,this study achieved a GPU-accelerated dose calculation method for mesh-type phantoms for the first time,reducing the computational time from hours to seconds per simulation of ten million particles and offering a swift and precise Monte Carlo method for dose calculation in mesh-type computational phantoms.
文摘目的:调查北京大兴区人民医院各台CT设备的辐射剂量水平和典型值,为提升辐射风险防范最优化提供依据。方法:回顾性分析2023年7月至12月5台CT设备头颅、胸部、腹部检查的扫描参数及辐射剂量数据,确定其典型值(中位数),并与国内外的诊断参考水平(DRL)进行比较。结果:本次调查头颅、胸部、腹部的容积CT剂量指数(CTDI_(vol))、剂量长度乘积(DLP)典型值分别为54.40 m Gy,735.80 m Gy·cm;14.20 m Gy,443.60 m Gy·cm;16.40 m Gy,678.20 m Gy·cm。头颅的CTDI_(vol)、DLP典型值最高,腹部次之,胸部最低。头颅CTDI_(vol)及DLP存在随年龄增加而略增大趋势。不同使用年限CT设备的头颅、腹部CTDI_(vol)、DLP存在显著性统计学差异。本次调查各部位DLP较其他国家偏低。除了头颅DLP稍偏大,其余辐射剂量均低于国家卫生行业标准。腹部DLP较其他省市偏大。结论:本次调查成人CT辐射剂量与国内外结果基本一致,需要对CT检查的扫描范围进行规范化培训和优化,以减少受检者不必要的辐射暴露。
