ROTATING FRAME RELAXATION MEASUREMENTS IN HUMAN LIVER ON CLINICAL SCANNERS

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 细胞外基质（ECM）是肝组织的主要成分，胶原、蛋白多糖、弹性蛋白等大分子物质是ECM的主要成分。目前，肝组织的侵入性活检是肝纤维化分期的金标准。虽然已经证明使用基于MRI的技术（如MR弹性成像）作为诊断和分级肝纤维化的非侵入性手段，但它们需要额外的剪切波生成装置。T1 <$加权（T1 <$-W）MRI是一种新兴的技术，用于探索不同病理的生化变化。尽管T1技术在量化与疾病相关的早期大分子变化方面具有巨大潜力，但由于呼吸运动、比吸收率（SAR）以及B 0和B1场不均匀性等实验挑战，尚未在体内肝组织中进行探索。在本研究中，我们的目标是开发和实施一种新的T1成像技术，能够在单次屏气中对肝脏进行T1标测，而不会超过1.5T和3 T临床扫描仪的SAR限值。还对正常和纤维化的离体组织进行了T1研究。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Extracellular matrix (ECM) is the main component of liver tissue and macromolecules like collagen, proteoglycan, elastin etc are major constituents of ECM. Currently, invasive biopsy of the liver tissue is the gold standard for staging liver fibrosis. While the use of MRI based techniques such as MR elastography as a non-invasive means to diagnose and grade hepatic fibrosis has been shown they require additional device for shear wave generation. T1¿-weighted (T1¿-W) MRI is an emerging technique for exploring the biochemical changes in different pathologies. In spite of significant potential of T1¿ technique to quantify early macromolecule changes related to disease, it hasn't been explored in-vivo liver tissue due to experimental challenges such as respiratory motion, specific absorption rate (SAR), and B0 and B1 field in-homogeneities. In the current study, our objective was to develop and implement a novel T1¿ imaging technique capable of T1¿ mapping of liver in a single breath- hold without exceeding SAR limits on 1.5T and 3T clinical scanners. T1¿ study was also carried on ex-vivo tissues both normal and fibrotic.