Giacometti V, Guatelli S, Bazalova-Carter M, Rosenfeld A B, Schulte R W
Centre for Medical Radiation Physics, University of Wollongong, Australia.
Centre for Medical Radiation Physics, University of Wollongong, Australia.
Phys Med. 2017 Jan;33:182-188. doi: 10.1016/j.ejmp.2017.01.007. Epub 2017 Jan 17.
Computational anthropomorphic phantoms have become an important investigation tool for medical imaging and dosimetry for radiotherapy and radiation protection. The development of computational phantoms with realistic anatomical features contribute significantly to the development of novel methods in medical physics. For many applications, it is desirable that such computational phantoms have a real-world physical counterpart in order to verify the obtained results. In this work, we report the development of a voxelised phantom, the HIGH_RES_HEAD, modelling a paediatric head based on the commercial phantom 715-HN (CIRS). HIGH_RES_HEAD is unique for its anatomical details and high spatial resolution (0.18×0.18mm pixel size). The development of such a phantom was required to investigate the performance of a new proton computed tomography (pCT) system, in terms of detector technology and image reconstruction algorithms. The HIGH_RES_HEAD was used in an ad-hoc Geant4 simulation modelling the pCT system. The simulation application was previously validated with respect to experimental results. When compared to a standard spatial resolution voxelised phantom of the same paediatric head, it was shown that in pCT reconstruction studies, the use of the HIGH_RES_HEAD translates into a reduction from 2% to 0.7% of the average relative stopping power difference between experimental and simulated results thus improving the overall quality of the head phantom simulation. The HIGH_RES_HEAD can also be used for other medical physics applications such as treatment planning studies. A second version of the voxelised phantom was created that contains a prototypic base of skull tumour and surrounding organs at risk.
计算人体模型已成为放射治疗和辐射防护中医学成像和剂量测定的重要研究工具。具有逼真解剖特征的计算模型的开发对医学物理新方法的发展做出了重大贡献。对于许多应用而言，期望此类计算模型具有实际的物理对应物，以便验证所获得的结果。在这项工作中，我们报告了一种体素化模型HIGH_RES_HEAD的开发，该模型基于商业模型715-HN（CIRS）对小儿头部进行建模。HIGH_RES_HEAD因其解剖细节和高空间分辨率（像素大小为0.18×0.18mm）而独具特色。开发这样一个模型是为了从探测器技术和图像重建算法方面研究一种新型质子计算机断层扫描（pCT）系统的性能。HIGH_RES_HEAD被用于一个专门的Geant4模拟中，对pCT系统进行建模。该模拟应用先前已根据实验结果进行了验证。与相同小儿头部的标准空间分辨率体素化模型相比，结果表明，在pCT重建研究中，使用HIGH_RES_HEAD可使实验结果与模拟结果之间的平均相对阻止本领差异从2%降低到0.7%，从而提高了头部模型模拟的整体质量。HIGH_RES_HEAD还可用于其他医学物理应用，如治疗计划研究。创建了体素化模型的第二个版本，其中包含颅骨肿瘤的原型基底和周围的危及器官。
