MRI-based Quantitative Susceptibility Mapping of Hepatic Iron Overload

基于 MRI 的肝铁过载定量磁化率图

• 批准号: 9902421
• 负责人: Diego Hernando
• 金额: $ 55.71万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9902421
• 关键词: Abdomen; Address; Adult; Affect; Biological Markers; Biopsy; Blood Transfusion; Brain; Breathing; Calibration; Chelating Agents; Child; Childhood; Clinical; Clinical Research; Data; Deposition; Detection; Development; Diagnosis; Etiology; Fatty acid glycerol esters; Goals; Hematological Disease; Hematology; Hepatic; Hereditary Disease; Hereditary hemochromatosis; Image; Institution; Iron; Iron Overload; Liver; Magnetic Resonance Imaging; Magnetism; Maps; Measurement; Measures; Methods; Microscopic; Monitor; Morphologic artifacts; Motion; Organ; Patients; Phase; Physicians; Physiological; Population; Predisposition; Property; Reference Standards; Reproducibility; Research; Resolution; Sampling; Signal Transduction; Staging; Techniques; Technology; Thrombocytopenia; Tissues; Transfusion; Translating; Translations; Validation; Work; base; chelation; clinical practice; cost; data acquisition; design; image reconstruction; imaging modality; in vivo; liver biopsy; magnetic field; novel; performance tests; prototype; public health relevance; quantitative imaging; respiratory; side effect; superconducting quantum interference device; validation studies

PROJECT SUMMARY / ABSTRACT The overall goal of this proposal is to develop and validate a novel technique for Magnetic Resonance Imaging (MRI)-based Quantitative Susceptibility Mapping (QSM) of the abdomen, for non-invasive assessment of liver iron deposition. In this work, we will develop and optimize advanced data acquisition and image reconstruction methods to enable QSM of the abdomen. Further, we will determine the accuracy, repeatability, and reproducibility of abdominal QSM for iron quantification in patients with liver iron overload. Excessive accumulation of iron in various organs, including the liver, which affects both adult and pediatric populations, is toxic and requires treatment aimed at reducing body iron stores. Accurate assessment of liver iron concentration is critical for the detection and staging of iron overload as well as for longitudinal monitoring during treatment. MRI is a widely available technology and highly sensitive to the presence of iron. Unfortunately, current MRI relaxometry methods are fundamentally limited by their poorly understood relationship to iron concentration, which depends on the type of iron overload and also varies during treatment. In contrast, MRI is also exquisitely sensitive to the magnetic susceptibility of tissue, which has a well-understood relationship to iron concentration. Magnetic susceptibility distorts the main magnetic field in a well-characterized manner, and this magnetic field distortion can be measured in-vivo. MRI-based QSM methods estimate the susceptibility of tissues based on measuring the magnetic field distortion produced by the tissues themselves. MRI- based QSM methods have been developed and validated in the brain. However, translation of QSM to the abdomen has been unsuccessful. We have identified four major technical barriers for development of QSM of the abdomen: 1) the presence of fat throughout the abdomen, which introduces additional phase shifts and confounds the susceptibility estimates, 2) the potential for very high iron concentration in the liver (compared to the brain), which results in rapid signal decay, 3) respiratory and other physiological motion, which introduces artifacts in the acquired images and estimated susceptibility maps, and 4) recently identified spatial resolution effects, which introduce bias in QSM when insufficient spatial resolution is acquired. By addressing these four barriers, we will develop a novel MRI-based QSM method for use in the abdomen to quantify liver iron overload. Preliminary validation studies are very promising and have shown excellent promise for the quantification of LIC in patients. In this proposal, we aim to [1] complete development of MRI-based abdominal QSM for measurement of LIC, [2] determine the repeatability and reproducibility of QSM at 1.5T and 3T in patients with liver iron overload, [3] determine the accuracy of abdominal QSM at 1.5T and 3T in patients with liver iron overload using superconducting quantum interference device (SQUID) biomagnetic liver susceptometry as the reference standard. In summary, this project will develop a novel MRI-based QSM technique designed for the abdomen and will validate it in pediatric and adult patients with liver iron overload. Upon successful validation, QSM will provide accurate, repeatable, and reproducible quantification of LIC based on a fundamental property of tissue.

项目概要/摘要 该提案的总体目标是开发和验证磁共振新技术 基于成像 (MRI) 的腹部定量磁敏感图 (QSM)，用于非侵入性 评估肝脏铁沉积。在这项工作中，我们将开发和优化先进的数据采集和 图像重建方法，以实现腹部的 QSM。此外，我们将确定准确性， 肝脏铁超负荷患者的铁定量腹部 QSM 的重复性和再现性。 铁在包括肝脏在内的各个器官中积聚过多，影响成人和儿童 对人群来说是有毒的，需要进行旨在减少体内铁储存的治疗。准确评估肝脏 铁浓度对于铁过载的检测和分级以及纵向监测至关重要 治疗期间。 MRI 是一种广泛使用的技术，对铁的存在高度敏感。不幸的是，目前的 MRI 弛豫测量方法从根本上受到其与铁浓度的关系知之甚少的限制， 这取决于铁过载的类型，并且在治疗过程中也会有所不同。相比之下，MRI 也 对组织的磁化率极其敏感，组织的磁化率与铁的关系众所周知 专注。磁化率以一种明确表征的方式扭曲主磁场，这 磁场畸变可以在体内测量。基于 MRI 的 QSM 方法估计 基于测量组织本身产生的磁场畸变的组织。 MRI- 基于 QSM 的方法已经在大脑中得到开发和验证。然而，将 QSM 翻译为 收腹没有成功。我们确定了QSM发展的四大技术壁垒 腹部：1）整个腹部存在脂肪，这会引入额外的相移和 混淆了敏感性估计，2）肝脏中铁浓度可能非常高（与 大脑），这会导致信号快速衰减，3）呼吸和其他生理运动，这引入了 采集图像和估计磁化率图中的伪影，以及 4) 最近确定的空间分辨率 当获得的空间分辨率不足时，会在 QSM 中引入偏差。 通过解决这四个障碍，我们将开发一种基于 MRI 的新型 QSM 方法，用于 腹部以量化肝脏铁超载。初步验证研究非常有希望，并且已经表明 为患者 LIC 定量提供了良好的前景。在本提案中，我们的目标是 [1] 完成 开发用于测量 LIC 的基于 MRI 的腹部 QSM，[2] 确定重复性和 肝脏铁超负荷患者 1.5T 和 3T 时 QSM 的重现性，[3] 确定 使用超导量子对肝铁超载患者进行 1.5T 和 3T 腹部 QSM 干扰装置（SQUID）生物磁肝电感受器作为参考标准。 总之，该项目将开发一种新型的基于 MRI 的 QSM 技术，专为腹部和 将在患有肝铁超载的儿童和成人患者中验证它。验证成功后，QSM 将 基于组织的基本特性，提供准确、可重复且可重现的 LIC 定量。