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.

项目摘要 /摘要 该提案的总体目标是开发和验证一种新型的磁共振技术 非侵入性的成像（MRI）基于腹部的定量敏感性映射（QSM） 评估肝铁沉积。在这项工作中，我们将开发和优化高级数据采集，并且 图像重建方法启用腹部的QSM。此外，我们将确定准确性 肝铁超负荷患者铁定量的腹部QSM的可重复性和可重复性。 在包括肝脏在内的各种器官中铁的过度积累，这会影响成人和小儿 种群是有毒的，需要旨在减少人体铁储存的治疗。准确评估肝脏 铁浓度对于铁超负荷的检测和分期至关重要，对于纵向监测至关重要 治疗期间。 MRI是一项广泛可用的技术，对铁的存在高度敏感。不幸的是，目前的MRI 弛豫方法从根本上受到其与铁浓度的关系不足的限制， 这取决于铁超负荷的类型，并且在治疗过程中也有所不同。相反，MRI也是 对组织的磁敏感性非常敏感，该组织与铁具有良好的关系 专注。磁敏感性以良好的方式扭曲了主磁场，这 磁场失真可以在体内测量。基于MRI的QSM方法估计 组织基于测量组织本身产生的磁场失真。 MRI- 在大脑中已经开发并验证了基于基于的QSM方法。但是，将QSM翻译成 腹部一直没有成功。我们已经确定了开发QSM的四个主要技术障碍 腹部：1）整个腹部存在脂肪，这引入了其他相移， 混淆易感性估计值2）肝脏中铁浓度很高的潜力（与 大脑），导致信号快速衰减，3）呼吸道和其他生理运动，这引入了 获得的图像和估计的敏感性图中的伪影，4）最近确定了空间分辨率 效果，当获取空间分辨率不足时会引入QSM中的偏差。 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 腹部以量化肝铁超负荷。初步验证研究非常有前途，并且已经表明 在患者中量化LIC的极好希望。在此提案中，我们的目标是[1]完成 开发基于MRI的腹部QSM用于测量LIC，[2]确定可重复性和 肝铁超负荷患者的QSM在1.5T和3T的可重复性，[3]确定的准确性 使用超导量子的肝铁超负荷患者的腹部QSM和3T的腹部QSM 干扰装置（Squid）生物磁肝脏逊到演作为参考标准。 总而言之，该项目将开发一种基于MRI的新型QSM技术，专为腹部和 将在儿科和成年患者肝铁超负荷的患者中进行验证。成功验证后，QSM将 根据组织的基本特性，提供准确，可重复和可重复的LIC定量。