CORRECTION OF SCATTER AND SPECTRAL ERRORS IN CT IMAGES

CT 图像中散射和光谱误差的校正

• 批准号: 2415590
• 负责人: PETER M JOSEPH
• 金额: $ 24.91万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2415590
• 关键词: X ray spectrometry; blood flow measurement; bone imaging /visualization /scanning; computed axial tomography; computer program /software; contrast media; diagnosis quality /standard; disease /disorder model; dogs; electromagnetic radiation; heart circulation; heart imaging /visualization /scanning; intravenous administration; iodine; method development; myocardial infarction; phantom model

The purpose of this proposed research is to implement and test a method for mitigating errors in x-ray CT scanners due to beam hardening in iodine. The central focus is the electron beam tomography (EBT) machine made by Imatron, which because it can produce a two dimensional image in as little as 50 milliseconds can be used for stop action imaging of the heart. Ideally, one would like to be able to give a patient an intravenous injection of standard iodine contrast agent, then image the flow of the agent through the myocardium in real time. The degree of CT number enhancement in the myocardium should be closely related to blood flow, so that perfusion defects could be seen and quantitated. However, the major impediment to this goal is the presence of artifacts due to scattered photons and beam hardening, especially beam hardening in the injected iodine. The latter effect is especially significant when there is substantial quantities of iodine in the cardiac chambers and can actually depress the CT number in the myocardium. We propose a systematic solution based on the physics of scattered photons and spectrum hardening in bone and iodine. Preliminary work has demonstrated a useable scattered photon correction which can still be improved. The method for hardening correction identifies bone and iodine in the uncorrected image and uses an algorithm previously developed by the author for hardening in bone. Detailed physiologic tests of the accuracy using a canine model are included.

本研究的目的是实现和测试一种方法 为了减少X射线CT扫描仪中由于射束硬化而产生的误差 碘。中心焦点是电子束断层摄影仪(EBT) 由Imatron制作，因为它可以在 短至50毫秒即可用于停止动作成像 心。理想情况下，人们希望能够为患者提供 静脉注射标准碘造影剂，然后成像 药剂通过心肌的实时流动。CT的程度 心肌细胞数量的增加应与血液密切相关 血流，以便可以看到和量化血流灌注缺陷。然而， 这一目标的主要障碍是由于以下原因而出现的人工制品 散射光子和光束硬化，特别是 注射了碘。后一种影响在以下情况下尤为显著 在心腔里有大量的碘，实际上可以 降低心肌CT值。我们提出了一个系统的解决方案 基于散射光子物理和骨骼中的光谱硬化 还有碘。初步工作证明了一种可用的散射光子 仍然可以改进的修正。硬化法 校正识别未校正图像中的骨骼和碘，并使用 作者以前开发的用于骨骼硬化的算法。 使用犬类模型对这种准确性进行了详细的生理测试 包括在内。