一种用于PET/CT呼吸运动伪影校正性能测试的动态体模设计

摘要

ObjectiveTo design a respiratory motion artifact correction performance test phantom which is used to quantitatively analyze the operating results of PET/CT respiratory gating system.Methods This thoracic cavity model was designed based on the image quality testing body model of American National Electrical Manufacturers Association, on which the inner diameter of the same aperture was used to insert content. The contents were internal cylinders that contain different diameters of hollow ball. Fluorodeoxyglucose solution was perfused into the hollow balls to simulate the size of lung cancer. Through a high-precision motor to control the elevation of the chest phantom, and simulate chest expansion and contraction of human respiratory; another high-precision motor was used to control the rotation, in and out of tumor mimics and simulated trajectories lung cancer with chest breathing.Results Compared with the standard image, preliminary experimental results indicated that the tumor deviation on three dimensions were 12.42 mm (axial), 13.36 mm (coronary) and 12.28 mm (sagittal) respectively, which was consistent with the clinical research. The results showed that the respiratory motion artifact correction performance test phantom could quantitatively evaluate the breathing artifact correction effects of respiratory movement control methods.ConclusionThismovable phantom is simple, and is not subject to the operational experience of clinical staffs and individual differences of experimental subject. The use of high-precision motor to control mold body movement reduces the impact of system error during actual operation and random error, while ensuring the reproducibility of the experiment.%目的：设计一种呼吸运动伪影校正性能测试体模，定量分析PET/CT呼吸门控系统的运行效果。方法本体模的胸腔模型是基于美国国家电器制造商协会的图像质量测试体模设计，其上预留了相同内径的孔径用来插入内容物。胸腔模型内容物是一个内部包含不同直径的空心球的圆柱体。空心球内部灌注FDG溶液，用来模拟肺部肿瘤的大小。通过一部高精度电机控制胸腔模体的升降，模拟人体呼吸时胸腔的扩张与收缩；通过另一部高精度电机控制肿瘤模拟物的旋转与进出，模拟肺部肿瘤随胸腔呼吸的运动轨迹。结果初步实验结果与标准图像对比，判断肿瘤在3个维度上的偏差为轴向12.42 mm，冠状13.36 mm，矢状12.28 mm，与临床研究的结果相一致，表明本呼吸运动伪影校正性能测试体模能够定量评价各呼吸运动控制方法呼吸伪影的校正效果。结论该动态体模操作方法简单，不受临床医护人员的操作经验和实验对象个体差异的干扰。使用高精度的电机控制模体运动，降低了实际操作中的系统误差和随机误差的影响，同时保证了实验的可重复性。