MRI Method for In Vivo Iron Quantification

体内铁定量的 MRI 方法

• 批准号: 7097389
• 负责人: JENS H JENSEN
• 金额: $ 25.93万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7097389
• 关键词: bioimaging /biomedical imaging; biomagnetism measurement; biopsy; clinical research; diagnosis design /evaluation; diagnosis quality /standard; diagnostic tests; ferritin; human subject; iron compounds; iron poisoning; liver imaging /visualization /scanning; magnetic resonance imaging; molecular /cellular imaging; patient oriented research; phantom model; superconductivity

DESCRIPTION (provided by applicant): The broad goal of the research is to develop a new magnetic resonance imaging (MRI) technique for quantifying body iron stores. Elevated body iron levels can develop in a variety of disorders, including hereditary hemochromatosis, thalassemia major, myelodysplasia, and sickle cell anemia. Excess body iron or "iron overload" can be toxic and may lead to a variety of iron-induced complications, such as diabetes, cirrhosis, and heart disease. In diagnosing and managing iron overload, it is important to quantify body iron excess. The two generally available clinical methods for doing this, liver biopsy and blood serum ferritin measurement, suffer from significant shortcomings. Liver biopsy is invasive and may be inaccurate for liver with cirrhosis, while the serum ferritin level correlates poorly with total body iron. The research would develop a method for iron quantification based on the effect of iron on MRI signal decay. The research would optimize and validate the technique for liver tissue, since liver iron concentration is considered the best single indicator of iron overload. A major advantage of MRI quantification of iron overload is that this method is completely non-invasive, which allows the frequent monitoring of iron levels during therapy. The proposed approach differs markedly from prior attempts to use MRI for iron quantification, in that two independent MRI quantities, rather than one, are measured. This is critical for obtaining a high accuracy, as iron in the liver comes in two forms, ferritin iron and hemosiderin iron, which affect MRI signal decay in significantly different ways. Our research will be divided into two stages. First, we will develop and test the necessary MRI pulse sequences using a tissue model (phantom) consisting of a gel with suspended iron particles. Second the method will be applied to 150 iron overload patients. As validation, the MRI predictions will be correlated to results of needle biopsy of the liver, the current clinical gold standard. We will also compare the MRI data to iron measurements obtained with SQUID biosusceptometry.

描述（由申请人提供）： 这项研究的主要目标是开发一种新的磁共振成像（MRI）技术，用于量化体内铁储存。体内铁水平升高可导致多种疾病，包括遗传性血色素沉着症、重型地中海贫血、骨髓增生异常和镰状细胞性贫血。体内过量的铁或“铁超载”可能是有毒的，并可能导致各种铁引起的并发症，如糖尿病，肝硬化和心脏病。在诊断和管理铁过载时，量化体内铁过剩是很重要的。两种通常可用的临床方法，肝活检和血清铁蛋白测量，具有明显的缺点。肝活检是侵入性的，可能是不准确的肝硬化，而血清铁蛋白水平与全身铁相关性差。该研究将开发一种基于铁对MRI信号衰减的影响的铁定量方法。这项研究将优化和验证肝脏组织的技术，因为肝脏铁浓度被认为是铁过载的最佳单一指标。MRI定量铁过载的一个主要优点是这种方法是完全无创的，这允许在治疗期间频繁监测铁水平。所提出的方法明显不同于先前尝试使用MRI进行铁定量，因为测量了两个独立的MRI量，而不是一个。这对于获得高准确性至关重要，因为肝脏中的铁有两种形式，铁蛋白铁和含铁血黄素铁，它们以显著不同的方式影响MRI信号衰减。我们的研究将分为两个阶段。首先，我们将开发和测试必要的MRI脉冲序列使用组织模型（幻影）组成的凝胶与悬浮的铁颗粒。其次，将该方法应用于150例铁超载患者。作为验证，MRI预测将与肝脏穿刺活检结果（当前的临床金标准）相关。我们还将比较MRI数据与SQUID生物阻抗测量法获得的铁测量值。