Time Resolved Cardiac Computed Tomography with Patient Dose Reduction

时间分辨心脏计算机断层扫描可减少患者剂量

• 批准号: 7659626
• 负责人: Katsuyuki Taguchi
• 金额: $ 38.43万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7659626
• 关键词: Affect; Agreement; Algorithms; Applications Grants; Arterial Fatty Streak; Cardiac; Cardiovascular Diseases; Cause of Death; Chest; Clinical; Computer Simulation; Computers; Coronary; Coronary artery; Data; Diastole; Dose; Early Diagnosis; Electrocardiogram; Electronics; Future; Generations; Goals; Heart; Image; Lung; Measures; Methods; Modeling; Morphologic artifacts; Motion; Nature; Noise; Organ; Patients; Performance; Perfusion; Phase; Process; Qualitative Evaluations; Radiation; Reading; Research; Resolution; Resting Phase; Scanning; Signal Transduction; Simulate; Techniques; Time; Tomography, Computed, Scanners; Tube; United States Public Health Service; Western World; X-Ray Computed Tomography; data acquisition; grasp; heart motion; image reconstruction; improved; interest; neglect; reconstruction; simulation; time use; tool; vector

DESCRIPTION (provided by applicant): Cardiovascular disease remains the leading cause of death in the western world, placing an ever-increasing burden on both private and public health services. The electrocardiogram (ECG)-gated cardiac CT imaging is a promising non-invasive technique for early detection of fatty vulnerable plaque in coronary arteries. However, there are two major problems with the current technique: large patient radiation dose and insufficient temporal resolution (TR). Currently, the typical radiation dose is 10-15 move, which is 3-5 times as large as a standard chest CT scan. The current TR is merely 80-165 ms in contrast to the minimum requirement of 10-30 ms to observe the beating heart motion without motion artifact. Current technique uses the ECG-signals to select projection data acquired in a time window that is placed within the "quiet" portion of the cardiac cycle (e.g., mid-diastole). Then, images are reconstructed by neglecting the cardiac motion within the time window resulting in blurring and artifacts in the reconstructed images. Also, this technique uses only 10-30% of the acquired data and throws away the rest of "off-phase" data, resulting in unnecessary radiation dose to the patient. The long-term goal of this research is to develop the time resolved, low dose cardiac CT imaging. Specifically, we will develop algorithms that estimate the time-dependent motion vector field of the heart from the measured data and integrate it into the image reconstruction process. The motion will be estimated by maximizing the agreement between the acquired 4D projection data and the reconstructed time-resolved 4D images. The quality of the image will be significantly improved since the motion is compensated. In addition, lower tube current could be utilized since all of the acquired data will be used to reconstruct any cardiac phase of interest. We estimate the reduction of radiation dose to the patient will be 50-75% of the current level. Our specific aims are: (1) to develop computer simulation tools necessary to study the problem, (2) to develop new methods that integrates the motion estimation and the image reconstruction algorithms for time resolved, low dose cardiac CT application, (3) to conduct the quantitative and qualitative evaluation of the performance of the new algorithms with various factors with patients and parameters used in the algorithms. The proposed methods will not only solve the current problems of motion blur and excessive radiation dose, but also enable future cardiac applications (e.g., correlation between the motion, perfusion and stenos is) that are not possible with the current techniques.

描述（由申请人提供）：心血管疾病仍然是西方世界的主要死亡原因，给私人和公共卫生服务带来了日益沉重的负担。心电图门控心脏CT成像是一种很有前途的无创技术，可用于冠状动脉脂肪易损斑块的早期检测。然而，目前的技术存在两个主要问题：患者辐射剂量大和时间分辨率（TR）不足。目前，典型的辐射剂量为10-15移动，是标准胸部CT扫描的3-5倍。当前的TR仅为80-165 ms，而观察没有运动伪影的心脏运动的最低要求为10-30 ms。目前的技术使用心电图信号来选择在心脏周期“安静”部分（如舒张中期）的时间窗口内获得的投影数据。然后，通过忽略时间窗内的心脏运动来重建图像，导致重建图像模糊和伪影。此外，该技术只使用了10-30%的采集数据，并丢弃了其余的“非相位”数据，导致对患者不必要的辐射剂量。本研究的长期目标是开发时间分辨、低剂量的心脏CT成像技术。具体来说，我们将开发算法，从测量数据中估计与时间相关的心脏运动矢量场，并将其整合到图像重建过程中。运动将通过最大化获取的四维投影数据和重建的时间分辨四维图像之间的一致性来估计。由于运动得到了补偿，图像的质量将得到显著改善。此外，由于所有获得的数据将用于重建任何感兴趣的心脏阶段，因此可以利用低管电流。我们估计病人的辐射剂量将减少到目前水平的50-75%。我们的具体目标是：(1)开发研究该问题所需的计算机仿真工具；(2)开发将运动估计和图像重建算法集成于时间分辨、低剂量心脏CT应用的新方法；(3)结合算法中使用的患者和参数，对各种因素的新算法的性能进行定量和定性评估。所提出的方法不仅可以解决当前运动模糊和辐射剂量过高的问题，而且还可以实现当前技术无法实现的未来心脏应用（例如运动，灌注和狭窄之间的相关性）。