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: 7837284
• 负责人: Katsuyuki Taguchi
• 金额: $ 23.29万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7837284
• 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死亡的主要原因，给私人和公共卫生服务带来了日益增加的负担。心电图 (ECG) 门控心脏 CT 成像是一种有前景的非侵入性技术，可用于早期检测冠状动脉中的脂肪易损斑块。然而，当前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 move，是标准胸部CT扫描的3-5倍。目前的 TR 仅 80-165 ms，而观察无运动伪影的跳动心脏运动的最低要求为 10-30 ms。当前技术使用 ECG 信号来选择在放置在心动周期的“安静”部分（例如，舒张中期）内的时间窗口中采集的投影数据。然后，通过忽略时间窗口内的心脏运动来重建图像，从而导致重建图像中的模糊和伪影。此外，该技术仅使用所采集数据的 10-30%，并丢弃其余的“异相”数据，从而导致患者受到不必要的辐射剂量。这项研究的长期目标是开发时间分辨、低剂量心脏 CT 成像。具体来说，我们将开发算法，根据测量数据估计心脏的时间相关运动矢量场，并将其集成到图像重建过程中。将通过最大化采集的 4D 投影数据和重建的时间分辨 4D 图像之间的一致性来估计运动。由于运动得到补偿，图像质量将显着提高。此外，可以利用较低的管电流，因为所有采集的数据将用于重建任何感兴趣的心脏相位。我们估计患者的辐射剂量将减少目前水平的 50-75%。我们的具体目标是：(1) 开发研究问题所需的计算机模拟工具，(2) 开发集成运动估计和图像重建算法的新方法，用于时间分辨、低剂量心脏 CT 应用，(3)根据算法中使用的患者和参数的各种因素对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的运动模糊和辐射剂量过多的问题，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）。