CT Method Development for Quantifying Myocardial Microvascular Flow Distribution

量化心肌微血管血流分布的 CT 方法开发

• 批准号: 8604416
• 负责人: Erik Leo Ritman
• 金额: $ 18.54万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-15 至 2014-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8604416
• 关键词: Accounting; Adenosine; Affect; Architecture; Area; Atherosclerosis; Blood Vessels; Blood Volume; Blood flow; Bolus Infusion; Caliber; Calibration; Clinical; Contrast Media; Coronary Circulation; Coronary artery; Data; Databases; Diabetes Mellitus; Discrimination; Disease; Distal; Evaluation; Family suidae; Generations; Geometry; Gold; Heart; Heterogeneity; Human; Hypertension; Image; Image Analysis; Individual; Iodine; Knowledge; Left atrial structure; Length; Location; Maps; Methodology; Methods; Microcirculation; Microspheres; Muscle; Myocardial; Myocardial Infarction; Myocardial perfusion; Myocardium; Organ; Patients; Perfusion; Photons; Procedures; Process; Regional Blood Flow; Resolution; Rest; Sampling; Scanning; Silver; Simulate; Slice; Spatial Distribution; Specimen; Stroke; Symptoms; Techniques; Time; Tissue Sample; Tissues; Trees; Work; X-Ray Computed Tomography; arteriole; base; density; digital; hemodynamics; indexing; innovation; interest; method development; millimeter; novel diagnostics; programs; public health relevance; tool; vasoconstriction

DESCRIPTION (provided by applicant): The objective of this proposal is to develop a tool for determining microvascular flow distribution from images of myocardium. This involves quantifying the spatial distribution of blood flow in arteriolar trees with lumen diameters in the range of 10 - 50 ¿m. High resolution micro-CT imaging will provide accurate 3D geometrical mapping of the microvascular architecture for a computational determination of the flow distribution. This "gold standard" will be used to calibrate estimates of sub-resolution regional blood flow distributions obtained by nested-region-of-interest (nROI) analysis of clinical MSCT images of myocardial perfusion. The significance of this proposal is that it will make it possible to probe deeper and more accurately into the mechanisms of microcirculatory disease processes in the myocardium and elsewhere (e.g., in diabetes mellitus, hypertension, and atherosclerosis). There is currently no imaging methodology for assessing quantitatively the state of microvasculature in humans with sufficient resolution as to allow the computation of flow distribution at the level of individual microvessels. The proposed method will provide a new tool for exploring novel diagnostic and treatment methods. The innovation in this proposal is that it will provide for the first time a 3D mapping of sub-resolution microvascular flow distribution with MSCT imaging methodology validated with micro-CT. AIM I - Generation of Whole-body and Micro-CT Image Data - Ia: Using pigs, generate an MSCT image sequence while the contrast bolus passes through the coronary circulation. Then, repeat this procedure while the LAD coronary artery is infused with adenosine. Next, inject 15 ¿m radiopaque microspheres (Ag impregnated) into the left atrium during resting flow conditions and then Au impregnated microspheres during the selected adenosine delivery rates. Ib: The heart will be removed and the LAD injected with Microfil. Several 1 cm3 muscle samples will be removed from the LAD perfusion territory. Each specimen will be scanned at (4 ¿m)3 voxel resolution. AIM II - Analysis of Convective Flow Distribution within the Microvasculature - IIa: The 3D micro-CT images of the specimens will be segmented so that our tree analysis program can provide the vascular lumen inter-branch segment diameter, length and branching angle and branch hierarchy in order to compute a hemodynamically-based flow distribution. IIb: The microspheres will be digitally isolated so that their location and density can be used to provide a microsphere-based flow distribution. IIc: The microsphere and hemodynamically based flow distributions will be compared and any differences will be accounted for to establish the true flow distribution. AIM III - Analysis of Spatial Heterogeneity of Myocardial Perfusion Within the Same Myocardial Regions -The MSCT images of the myocardium will be subjected to nROI analysis and used to compute the spatial distribution of intramyocardial blood volume and flow and the results will be calibrated by the distribution of flow and intraluminal blood volume as derived from the micro-CT results in IIb, c.

描述（由申请人提供）：本提案的目的是开发一种用于根据心肌图像确定微血管血流分布的工具。这涉及到量化管腔直径在10 - 50 μ m范围内的小动脉树中血流的空间分布。高分辨率微CT成像将提供精确的微血管结构的3D几何映射，用于计算确定流量分布。该“金标准”将用于校准通过对心肌灌注临床MSCT图像进行嵌套感兴趣区域（nROI）分析获得的亚分辨率区域血流分布估计值。这一提议的意义在于，它将使更深入和更准确地探索心肌和其他地方的微循环疾病过程的机制成为可能（例如，糖尿病、高血压和动脉粥样硬化）。目前还没有成像方法用于定量评估人类微血管系统的状态，其具有足够的分辨率以允许计算单个微血管水平的流量分布。该方法将为探索新的诊断和治疗方法提供新的工具。该提案的创新之处在于，它将首次提供亚分辨率微血管流量分布的3D映射， 使用micro-CT验证MSCT成像方法。 目的I -全身和显微CT图像数据的生成- Ia：使用猪，在造影剂团通过冠状动脉循环时生成MSCT图像序列。然后，重复此程序，同时向LAD冠状动脉注入腺苷。接下来，注入15磅在静息血流条件下，将不透射线的微球（Ag浸渍）注入左心房，然后在选定的腺苷递送速率下将Au浸渍的微球注入左心房。Ib：将取出心脏，并将Microfil注入LAD。将从LAD灌注区域中取出几个1 cm 3的肌肉样本。将以（4 μ m）3体素分辨率扫描每个标本。目的II -微血管系统内对流流量分布分析- IIa：将对样本的3D micro-CT图像进行分割，以便我们的树分析程序可以提供血管腔间分支段直径、长度和分支角度以及分支层次，从而计算基于血流动力学的流量分布。IIb：微球将被数字隔离，以便其位置和密度可用于提供基于微球的流量分布。IIc：将比较微球和基于血流动力学的流量分布，并考虑任何差异以确定真实流量分布。目的III -相同心肌区域内心肌灌注的空间异质性分析-心肌的MSCT图像将接受nROI分析，并用于计算心肌内血容量和流量的空间分布，结果将通过流量和管腔内血容量的分布进行校准，如IIb、c中的micro-CT结果所示。