DEVELOPMENT OF AN EMISSION TRANSMISSION CT SYSTEM

该项目将开发一种新的成像技术， 定位和体内测量的准确度和精密度 单光子放射性药物 该项目将包括一个医疗 使用相邻常规CT和SPELT的成像系统（X-SPELT） 用于关联基于发射的功能数据的成像系统， 来自共配准的X射线透射图像的解剖数据。 这 建议包括四个具体目标。 (1)我们将开发技术， 补偿放射性核素数据的几何响应效应 包括（a）用以下方法量化放射性核素数据： 在CT图像上定义的感兴趣区域，以及（B）定义恢复 具有来自CT图像的结构信息的系数来补偿 部分体积误差的SPELT图像，以及（c）结合结构 直接使用SPELT重建算法。 (2)我们将 使用一种技术开发分散分布， 结构信息从CT衍生的衰减图，并比较它 相对于传统的散射校正技术。(3)体模实验 将进行肿瘤和心肌灌注成像，以评估 根据具体目标1和2开发的补偿技术， 包括光子的组合效应的实验条件 衰减、散射辐射、噪声和部分体积效应。 （四） 最后，确定X-SPELT系统的准确度和精密度 用于测量猪心肌模型中Tc-99 m-MIBI摄取 灌注测试的假设，CT扫描可以用来评估 心肌壁厚度，以获得参数，以补偿 放射性核素数据的部分体积效应，并纠正相关的 由散射辐射引起的误差的图像。 这些研究将 评估发射透射成像的性能， 使用蒙特卡罗计算机模拟的定量放射性核素研究， 体模研究和动物实验测量， 改善心肌放射性核素评估的中期目标 灌注，并将这些技术应用于 人体心肌灌注和肿瘤剂量学评价方法改进 用单光子放射性核素获得的患者。

This project will develop a new imaging technique which improves the localization and the accuracy and precision of in vivo measurements of single-photon radiopharmaceutical. The project will incorporate a medical imaging system (X-SPELT) which uses adjacent conventional CT and SPELT imaging systems for correlating emission-based functional data and anatomical data from a coregistered x-ray transmission image. This proposal encompasses 4 specific aims. (1) We will develop techniques to compensate the radionuclide data for the effects of the geometric response of the SPELT system including (a) quantifying the radionuclide data with regions of interest defined on the CT image, and (b) defining recovery coefficients with structural information from the CT image to compensate the SPELT image for partial volume errors, and (c) incorporating structural information directly with the SPELT reconstruction algorithm. (2) We will develop scatter distribution using a technique which incorporates structural information from the CT-derived attenuation map, and compare it against conventional scatter correctin techniques. (3) Phantom experiments of tumor and myocardial perfusion imaging will be performed to evaluate the compensation techniques developed under Specific Aim 1 and 2, under experimental conditions which include the combined effects of photon attenuation, scatter radiation, noise, and partial volume effects. (4) Finally, the accuracy and precision of X-SPELT system will be determined for measurement of Tc-99m-MIBI uptake in a porcine model of myocardial perfusion to test the hypothesis that CT scans can be used to assess myocardial wall thickness to derive parameters to compensate the radionuclide data for partial volume effects, and to correct the correlated images for errors contributed by scattered radiation. These studies will evaluate the performance of the emission-transmission imaging for quantative radionuclide studies using Monte Carlo computer simulation, phantom studies, and experimental measurements in animals, with the intermediate goal of improving radionuclide assessments of myocardial perfusion, and with the long-term goal of applying these techniques to improve assessments of myocardial perfusion and tumor dosimetry in human patients obtained with single-photon radionclides.