MR IMAGING AND COMPUTER RECONSTRUCTION OF FLOW PATTERNS

流型的 MR 成像和计算机重建

• 批准号: 2222996
• 负责人: MICHAEL H BUONOCORE
• 金额: $ 8.21万
• 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/2222996
• 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速度编码相位成像具有快速、准确的潜力 以及精确确定三维血流模式。据信， 如果显示和量化这些流动模式的能力 容易获得的、常规的诊断利用将会出现。即刻 诊断应用包括改进的传统 心血管参数，如心输出量，每搏量， 回流分数、压力梯度和定量评估 血管性动脉瘤和畸形。测量是一种新的应用 根据测量的左、右冠状动脉总血流速度 在升主动脉、主动脉根部和它们的近端 船只。 应用程序的广泛、长期目标是开发 快速、准确和精确的磁共振成像技术用于重建和 三维血流模式的可视化。应用程序将开发(%1) 心脏门控、有限视场(FOV)三维速度编码脉冲 用于生成速度数据的序列，以及(2)基于 用于重建和显示流型的流体力学。 将使用选择性射频信号抑制或激励来实现 采用小视场和少量相位编码的三维数据采集 每个方向的步数。速度数据的准确性和精确度将 通过采用二维脉冲序列方法来实现。时间编码 流线将被用来可视化流动模式。流体力学 守恒定律、容器边界和恒定流量约束 施加在3-D速度数据上，以显著改善内部 数据的一致性和重建的准确性和精确度 流线型。 这项新技术将应用于冠状动脉的测量 流。虽然几个小组已经开发出优化的脉冲序列以 想像一下冠状动脉，测量总流量还不够 可靠。流量测量脉冲序列设计的不同之处在于 需要(I)高时间分辨率以消除因以下原因引起的误差 脉动性，(2)薄片，最大限度地减少部分体积误差，以及(3) 整个RR间期的数据采集。三维脉冲序列 将在单个序列中测量上升过程中的血流速度 主动脉，Valsalva窦，通向冠状动脉，并在 冠状动脉。重建算法将改进 速度数据的内部一致性，并生成流型 与流体动力学约束一致。