Validation of a Monte Carlo tool for patient-specific dose simulations in multi-slice computed tomography
Validation of a Monte Carlo tool for patient-specific dose simulations in multi-slice computed tomography
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DOI：
10.1007/s00330-007-0815-7
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发表时间：
2008-04-01
影响因子：
5.9
通讯作者：
Kalender, Willi A.
中科院分区：
文献类型：
--
作者：
Deak, Paul;van Straten, Marcel;Kalender, Willi A.
在X射线计算机断层扫描（CT）检查中估计输送给患者的剂量不是一项微不足道的任务。蒙特卡罗（MC）方法似乎是评估3D剂量分布的首选方法。这项工作的目的是扩展现有的基于MC的工具，以考虑任意扫描仪和扫描协议，如多层CT（MSCT）扫描仪，并在同质和异构体模中验证该工具。该工具进行了验证，在已知条件下的不同扫描协议的MSCT扫描仪上的测量。定量CT剂量指数（CTDI）的测量进行了圆柱形CTDI模型和在拟人的胸部模型的各种大小，剂量分布进行了测量与热释光剂量计（ESTA）的CTDI模型和计算的剂量分布进行了比较。面内剂量分布进行了模拟，并与在Alderson-Rando体模中的剂量测量值进行了比较。对于所有体模和所有研究条件，计算的剂量值通常在测量值的10%以内。三维剂量分布可以准确地计算与MC工具的任意扫描仪和协议，包括管电流调制方案。同时，该工具的使用也扩展到其他扫描仪和平板探测器CT。
Estimating the dose delivered to the patient in X-ray computed tomography (CT) examinations is not a trivial task. Monte Carlo (MC) methods appear to be the method of choice to assess the 3D dose distribution. The purpose of this work was to extend an existing MC-based tool to account for arbitrary scanners and scan protocols such as multi-slice CT (MSCT) scanners and to validate the tool in homogeneous and heterogeneous phantoms. The tool was validated by measurements on MSCT scanners for different scan protocols under known conditions. Quantitative CT Dose Index (CTDI) measurements were performed in cylindrical CTDI phantoms and in anthropomorphic thorax phantoms of various sizes; dose profiles were measured with thermoluminescent dosimeters (TLD) in the CTDI phantoms and compared with the computed dose profiles. The in-plane dose distributions were simulated and compared with TLD measurements in an Alderson-Rando phantom. The calculated dose values were generally within 10% of measurements for all phantoms and all investigated conditions. Three-dimensional dose distributions can be accurately calculated with the MC tool for arbitrary scanners and protocols including tube current modulation schemes. The use of the tool has meanwhile also been extended to further scanners and to flat-detector CT.