MR IMAGING AND COMPUTER RECONSTRUCTION OF FLOW PATTERNS

流型的 MR 成像和计算机重建

• 批准号: 2222997
• 负责人: MICHAEL H BUONOCORE
• 金额: $ 10.66万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-09-30 至 1997-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2222997
• 关键词: angiography; cardiovascular disorder diagnosis; cardiovascular imaging /visualization; computer simulation; diagnosis quality /standard; heart circulation; image processing; magnetic resonance imaging; mathematical model; rapid diagnosis; swine; technology /technique development

MRI velocity encoded phase imaging has the potential for rapid, accurate and precise determination of 3-D blood flow patterns. It is believed that if the capability to display and quantitate these flow patterns were readily available, routine diagnostic utilization would emerge. immediate diagnostic applications include improved measurement of traditional cardiovascular parameters such as cardiac output, stroke volume, regurgitant fractions, pressure gradients, and quantitative assessment of vascular aneurysms and malformations. A new application is the measurement of total left and right coronary artery flow from measurements of velocity in the ascending aorta, aortic root, and proximal portions of these vessels. The broad, long term objective of the application is the development of rapid, accurate and precise MR imaging techniques for reconstruction and visualization of 3-D blood flow patterns. The application will develop (1) cardiac gated, limited field of view (FOV) 3-D velocity encoded pulse sequences for generation of velocity data, and (2) algorithms based on fluid mechanics for reconstruction and display of the flow patterns. Selective RF signal suppression or excitation will be used to allow collection of 3-D data with a small FOV and small number of phase encode steps in each direction. Accuracy and precision of the velocity data will be achieved by adapting 2-D pulse sequence methodology. Time-coded streamlines will be used to visualize the flow patterns. Fluid dynamics conservation laws, vessel boundary, and constant flux constraints will be imposed on the 3-D velocity data to significantly improve the internal consistency of the data and the accuracy and precision of reconstructed streamlines. The new techniques will be applied to the measurement of coronary artery flow. While several groups have developed optimized pulse sequences to visualize the coronary arteries, measurement of total flow is not yet reliable. Differences in pulse sequence design for flow measurement are the need for (I) high temporal resolution to eliminate errors due to pulsatility, (2) thin slices to minimize partial volume errors, and (3) data acquisition through the entire RR interval. The 3-D pulse sequences will measure, in a single sequence, the blood velocity in the ascending aorta, sinuses of Valsalva leading into the coronary arteries, and within the coronary arteries. The reconstruction algorithms will improve the internal consistency of the velocity data and generate flow patterns that are consistent with fluid dynamics constraints.

MRI速度编码的相成像具有快速，准确的潜力 并精确测定3-D血流模式。相信 如果显示和量化这些流模式的能力是 随时可以出现常规诊断利用。即时 诊断应用包括改进的传统测量 心血管参数，例如心脏输出，中风量， 反流分数，压力梯度和定量评估 血管动脉瘤和畸形。新应用是测量 左右冠状动脉的总动脉流量的速度测量值 在上升主动脉，主动脉根和近端部分中 船只。 该应用的广泛，长期目标是开发 快速，准确和精确的MR成像技术，用于重建和 3-D血流模式的可视化。应用程序将开发（1） 心脏门控，有限的视野（FOV）3-D速度编码脉冲 生成速度数据的序列，以及（2）基于算法 用于重建和表现流图的流体力学。 选择性RF信号抑制或激发将用于允许 收集带有少量FOV和少量相编码的3-D数据 朝每个方向踩踏。速度数据的准确性和精度将 可以通过调整2D脉冲序列方法来实现。时间编码 流线将用于可视化流图。流体动力学 保护法律，船舶边界和恒定通量约束将是 强加了3-D速度数据以显着改善内部 数据的一致性以及重建的精度和精度 流线。 新技术将应用于冠状动脉的测量 流动。虽然几个组已经开发了优化的脉冲序列 可视化冠状动脉，总流量的测量尚未 可靠的。流量测量的脉冲序列设计差异为 需要（i）高时间分辨率以消除由于 脉动性，（2）薄片以最大程度地减少部分体积误差，（3） 通过整个RR间隔获取数据。 3-D脉冲序列 将以单个序列测量上升的血液速度 主动脉，瓦尔萨尔瓦的鼻窦通向冠状动脉，内部 冠状动脉。重建算法将改善 速度数据的内部一致性并生成流动模式 与流体动力学约束一致。