TOMOGRAPHIC DOSIMETRY PHANTOMS FOR PEDIATRIC RADIOLOGY

描述(摘自申请者摘要)：透视和计算机 体层摄影术正越来越多地应用于儿科医学。 因此，确定儿科患者器官剂量的定量方法如下 对临床决策和风险评估至关重要。偶数近似 基于进入剂量或能量测量的风险评估方法 传授，基本上依赖于知识或器官剂量。器官剂量可能是 通过使用诊断检查的计算机模拟来确定 拟人化模型，或通过使用嵌入在 拟人化的身体幻影。拟人化计算模型可能是 进一步分类为风格化模型，其中器官由3D描绘 表面方程，或层析模型，其中器官是由 分割的CT或MRI图像。在这个项目中，调查人员将开发出 两种方法中估计新生儿器官剂量的改进技术 透视和CT检查。项目的具体目标是：1) 构建高分辨率、分段层析成像计算模型 新生儿使用活体新生儿螺旋CT图像。模型将是 比例与MIRD新生儿模型的尺寸和器官质量相匹配； 2)构建活体的高分辨率层析物理模型 新生儿使用相同的CT数据，并且也进行了缩放以匹配MIRD新生儿 模特。风格化的MIRD模型的全尺寸物理模型也将是 建造的。将使用Embedded来评估内部器官剂量 高灵敏度MOSFET剂量计；3)测定新生儿器官剂量 儿童在透视和CT检查期间接受的检查 在具体目标1和2中开发的计算模型和物理幻影， 4)评价解剖学改进的程度。 无论是在计算模型中还是在物理幻影中，表征都会影响 新生儿放射检查中器官剂量的估算。

DESCRIPTION (Adapted from Applicant's Abstract): Both fluoroscopy and computed tomography are becoming increasingly utilized in pediatric medicine. Quantitative methods for determining organ dose in pediatric patients are thus essential for clinical decision-making and risk assessment. Even approximate methods of risk assessment, based upon measures of entrance dose or energy imparted, fundamentally rely upon knowledge or organ dose. Organ doses may be determined through either computational simulation of the diagnostic exam using anthropomorphic models, or through the use of dosimeters embedded within anthropomorphic physical phantoms. Anthropomorphic computational models may be further classified as either stylized models, where organs are delineated by 3D surface equations, or tomographic models, in which organs are determined from segmented CT or MRI images. In this project, the investigators will develop improved techniques for estimating organ doses to the newborn child in both fluoroscopic and CT examinations. The project Specific Aims are: 1) to construct a high-resolution, segmented tomographic computational model of a newborn child using helical CT images of live newborns. The model will be scaled to match the dimensions and organ masses of the MIRD newborn model; 2) to construct a high-resolution tomographic physical phantom of a live newborn using the identical CT data and also scaled to match the MIRD newborn model. A full-scale physical phantom of the stylized MIRD model will also be constructed. Internal organ doses will be assessed using embedded high-sensitivity MOSFET dosimeters; 3) to determine organ doses in the newborn child received during fluoroscopic and CT examinations using both the computational model and physical phantoms developed in Specific Aims 1 and 2, respectively; and 4) to evaluate the degree to which improved anatomic representation, in either computational models or physical phantoms, influences estimates of organ dose in newborn radiological examinations.