MRI method for quantitatively mapping cerebral microbleeds

定量绘制脑微出血图的 MRI 方法

• 批准号: 8251167
• 负责人: Yi Wang
• 金额: $ 35.24万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-15 至 2016-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8251167
• 关键词: Algorithms; Anticoagulation; Blood; Brain; Brain scan; Calcium; Calibration; Cerebral hemisphere hemorrhage; Cerebrum; Clinical; Data; Deposition; Detection; Disease; Equation; Erythrocytes; Evaluation; Extravasation; Financial compensation; Heart; Hemorrhage; Hemosiderin; Image; Image Analysis; Investigation; Iron; Iron Compounds; Lead; Lesion; Life; Longitudinal Studies; Magnetic Resonance Imaging; Magnetism; Maps; Measurement; Measures; Medicine; Methods; Morphologic artifacts; Morphology; Motion; Organic Iron Compounds; Patients; Phase; Predisposition; Prevention; Property; Quantitative Evaluations; Research; Resolution; Risk; Risk Assessment; Severities; Signal Transduction; Source; Stroke; Structure; Sum; Technology; Time; Tissue Extracts; Tissues; Validation; Warfarin; Weight; attenuation; base; blood product; calcification; data acquisition; effective therapy; high risk; imaging modality; in vivo; interest; magnetic field; mortality; neglect; novel; novel strategies; physical property; public health relevance; reconstruction; research and development; simulation

DESCRIPTION (provided by applicant): The objective of this research is to develop a quantitative MRI method for mapping iron deposits in cerebral microbleeds (CMB). There is significant scientific and clinical interest in studying CMB, which are focal lesions of hemosiderin deposits from red blood cells leaked out of small brain vessels. CMB have become an important concern for managing stroke patients, particularly for assessing the risk of devastating intracerebral hemorrhage (ICH) in patients under anticoagulation. Quantitative mapping of iron deposits in CMB can be very valuable for stratifying risk of anticoagulation therapy. Currently, dark regions in T2* weighted MRI have been used to identify the presence of iron by interpreting the observed signal loss caused by the intravoxel dephasing effect of local magnetic fields of iron deposits. This hypointensity depends on voxel size and orientation, may be confused with other signal voids, and does not allow accurate quantification of iron. We propose a novel quantitative susceptibility mapping (QSM) approach to generate quantitative mapping of iron deposits using MRI by making full use of both phase and magnitude information in the T2* gradient echo image data. The phase image, typically neglected in MRI, is used to generate a local magnetic field map for fitting with susceptibility via the Maxwell equation. The magnitude image is used to extract tissue structure information for matching with susceptibility interfaces via least discordance. This morphology enabled dipole inversion approach is feasible for quantitatively mapping iron compound concentrations, as demonstrated in our preliminary studies, therefore enabling standardized and quantitative evaluation of CBM. Our proposed research consists of the following specific aims for developing and applying brain iron mapping technology. 1) Optimize data acquisition for mapping fields of CMB in the whole brain. 2) Develop a robust reconstruction for QSM of CMB iron deposits. 3) Validate QSM of bleeds and microbleeds in the brain using histological correlation. 4) Apply QSM to measure CMB in warfarin-treated patients with and without ICH. PUBLIC HEALTH RELEVANCE: This proposed research will develop a quantitative susceptibility mapping of iron deposits in cerebral microbleeds using noninvasive MRI for assessing the risk of intracerebral hemorrhage in patient treated with warfarin. There is an urgent need to standardize the MRI evaluation of cerebral microbleeds, a known risk for the devastating intracerebral hemorrhage in hypertensive patients. Currently MRI is the method of choice for the detection of cerebral microbleeds, but it is not quantitative. Successful development of this research would lead to a standardized evaluation of cerebral microbleeds and an accurate assessment of the risk of intracerebral hemorrhage for patients under warfarin treatment for their heart problems.

描述（由申请人提供）：本研究的目的是开发一种定量 MRI 方法，用于绘制脑微出血 (CMB) 中的铁沉积图。研究 CMB 具有重大的科学和临床意义，CMB 是从小脑血管渗漏出来的红细胞引起的含铁血黄素沉积的局灶性病变。 CMB 已成为管理中风患者的一个重要问题，特别是评估接受抗凝治疗的患者发生毁灭性脑出血 (ICH) 的风险。 CMB 中铁沉积物的定量绘图对于分层抗凝治疗的风险非常有价值。目前，T2* 加权 MRI 中的暗区已被用于通过解释由铁沉积物局部磁场的体素内相移效应引起的观察到的信号损失来识别铁的存在。这种低强度取决于体素的大小和方向，可能与其他信号空洞混淆，并且不允许铁的精确定量。 我们提出了一种新颖的定量磁化率绘图（QSM）方法，通过充分利用 T2* 梯度回波图像数据中的相位和幅度信息，使用 MRI 生成铁矿床的定量绘图。通常在 MRI 中被忽略的相位图像用于生成局部磁场图，以便通过麦克斯韦方程拟合磁化率。幅度图像用于提取组织结构信息，以便通过最小不一致性与磁化率界面进行匹配。正如我们的初步研究所证明的那样，这种形态学偶极子反演方法对于定量绘制铁化合物浓度是可行的，因此可以对煤层气进行标准化和定量评估。我们提出的研究包括以下开发和应用脑铁图谱技术的具体目标。 1）优化全脑CMB区域图谱数据采集。 2) 开发 CMB 铁矿床 QSM 的稳健重建。 3) 使用组织学相关性验证大脑中出血和微出血的 QSM。 4) 应用 QSM 测量华法林治疗的患有和不患有 ICH 的患者的 CMB。 公共健康相关性：这项拟议的研究将使用无创 MRI 开发脑微出血中铁沉积物的定量磁化率图，以评估接受华法林治疗的患者发生脑出血的风险。迫切需要标准化脑微出血的 MRI 评估，脑微出血是高血压患者发生毁灭性脑出血的已知风险。目前，MRI 是检测脑微出血的首选方法，但它不是定量的。这项研究的成功开展将有助于对脑微出血进行标准化评估，并准确评估因心脏病而接受华法林治疗的患者发生脑出血的风险。