Determination of myocardial triglyceride using magnetic resonance imaging

描述（由申请人提供）：使用磁共振成像测定心肌甘油三酯心脏舒张和收缩功能异常可能与动物模型中心肌细胞的过度脂解和脂毒性损伤有关。脂质的过度储存，称为心脏脂肪变性，产生脂毒性物质，导致氧化应激，并可引起细胞凋亡。心肌异位脂肪沉积的测量可以提供一个有用的指标的程度脂质过载。该提案的总体目标是使用磁共振成像（MRI）开发稳健的成像生物标志物，以提高心脏脂肪变性的诊断准确性和表征。 已经采用了几种方法来量化人类的异位脂肪沉积。质子磁共振波谱（1H MRS）已被证明是可靠的和可重复的测量心肌甘油三酯含量在人类。然而，MRS是一种相对复杂和耗时的方法，需要大量的后处理。使用MRI量化脂肪浸润可能有新的机会。为了准确地量化脂肪分数，应该解决四个主要问题：组织松弛的影响，图像噪声，以及导致同相和异相回波时间偏移的均匀性场。然而，在过去的几年里，PI已经解决了脂肪变性准确评估的问题。在该提案的第一阶段，重点是技术开发和离体实验，以验证我们的新概念和新的脂肪-水分离方法在3.0T磁场。接下来，我们将在患者中评估该技术与MRS结果的相关性。我们将使用所提出的方法在3.0T临床环境中评估糖尿病或HIV感染患者。最终，我们建议实现脂肪变性的量化，误差小于0.5%，以提供准确的脂肪变性评估，密切监测疾病进展。 公共卫生相关性：利用磁共振成像测定心肌甘油三酯心肌中脂肪的过度储存，称为心脏脂肪变性，产生脂毒性物质，导致心脏舒张和收缩功能异常，并可导致心脏细胞死亡。该提案的总体目标是使用磁共振成像（MRI）开发稳健的成像生物标志物，以提高心脏脂肪变性的诊断准确性和表征。

DESCRIPTION (provided by applicant): Determination of myocardial triglyceride using magnetic resonance imaging Cardiac abnormalities in diastolic and systolic function can be associated with excessive lipolysis and lipotoxic injury to cardiomyocytes in animal models. The overstorage of lipids, known as cardiac steatosis, produces lipotoxic substances that result in oxidative stress and can cause apoptosis. Measurement of the ectopic fat deposition in the myocardium may provide a useful index of the degree of lipid overload. The overall aim of this proposal is to develop robust imaging biomarkers using magnetic resonance imaging (MRI) to improve the diagnosis accuracy and characterization of cardiac steatosis. Several methods have been employed to quantify ectopic fat deposition in humans. Proton Magnetic Resonance Spectroscopy (1H MRS) has proven to be reliable and reproducible in measuring myocardial triglyceride content in humans. However, MRS is a relatively complicated and time-consuming method requiring extensive post-processing. New opportunities may be available to quantify fatty infiltration using MRI. To accurately quantify the fat fraction, four major issues should be addressed: the effect of tissue relaxation, image noise, and the field in homogeneity that results in a shift of in- and out-phase echo times. Over the past years, however, the PI has addressed the issues of accurate assessment of steatosis. In the first phase of this proposal, the focus is on the technical developments and ex-vivo experiments to validate our novel concepts and new fat-water separation methods at 3.0T magnetic field. Next, we will evaluate this technique in patients in correlation to the MRS results. We will evaluate patients with diabetes or HIV infection in a 3.0T clinical setting using the proposed methods. Ultimately we propose to achieve quantification of steatosis with less than 0.5% error to provide accurate assessment of steatosis for close monitoring of the disease progress. PUBLIC HEALTH RELEVANCE: Determination of myocardial triglyceride using magnetic resonance imaging the over-storage of fat in the heart muscle, known as cardiac steatosis, produces lipotoxic substances that result in cardiac abnormalities in diastolic and systolic function and can cause heart cell death. The overall aim of this proposal is to develop robust imaging biomarkers using magnetic resonance imaging (MRI) to improve the diagnosis accuracy and characterization of cardiac steatosis.