MRI Visceral Adipose Tissue Partitioning:Advanced Models

描述(由申请者提供)：过度肥胖正在成为美国最严重的健康问题。尽管总体脂肪组织(AT)占美国成年人平均体重的四分之一以上，但只有某些相对较小的高活性间隔与发病率密切相关。其中研究最广泛的是内脏脂肪组织(VAT)。目前，测量VAT是人类肥胖表型的核心，公认的参考测量方法是磁共振成像(MRI)和计算机断层扫描(CT)。由于受到辐射照射，CT的适用性有限。传统的定量VAT的成像方法是使用CT或MRI测量L4-L5椎体水平的VAT横截面面积。L4-L5水平是一个解剖位置，很大程度上是为了方便而建立的，作为增值税总额的代表。我们团队最近完成的一项广泛的审查显示，通过成像方法测量增值税的研究之间存在巨大差异。考虑到迫切需要改进表型，并监测干预措施对重要脂肪组织隔室的微小但代谢显著的影响，这种缺乏共识是令人担忧的。最近的研究表明，腹膜内AT，主要是大网膜和肠系膜AT，是增值税的组成部分，最强烈地将肥胖与不良的生物学结果和发病率联系在一起。腹膜内AT主要不局限于L4-L5，而是在更高的水平，我们有初步数据表明，其他解剖位置可能与不希望的代谢指标水平更密切相关。此外，总增值税包含多种AT成分，可能不是腹膜内AT或预后的最佳标记物。为了研究这些问题，我们建议收集和分析迄今为止最大的(约3000次扫描)和最多样化的全身MRI数据库，这些数据库与相关的身体成分和实验室研究相关联。汇集的图像和数据将为将MRI研究扩展到新兴的高分辨率图像采集领域提供所需的初始数据和理论基础。它还将允许测试与方法、模型开发和生物学兴趣有关的许多其他重要假设。我们的发现有助于为增值税和脂肪组织亚室测量设定新的标准，降低磁共振身体成分研究的成本，并提高研究能力。

DESCRIPTION (provided by applicant): Excessive adiposity is emerging as the nation's most significant health problem. Although total body adipose tissue (AT) accounts for more than one-fourth of body mass in the average American adult, only certain relatively small highly active compartments are strongly associated with morbidity. The most widely studied of these is visceral adipose tissue (VAT). Measuring VAT is currently central to phenotyping human subjects for obesity and the accepted reference measurement methods are magnetic resonance imaging (MRI) and computed tomography (CT). CT is of limited applicability due to radiation exposure. The traditional imaging approach for quantifying VAT is to measure the cross-sectional VAT "area" at the level of the L4-L5 vertebrae using CT or MRI. The L4-L5 level is an anatomic location established largely by convenience as representative of total VAT. An extensive recent review completed by our group reveals large discrepancies across studies in VAT measurement by imaging methods. This lack of consensus is troubling in view of the critical need for improved phenotyping and for monitoring small but metabolically significant effects of interventions on important adipose tissue compartments. Recent studies suggest that intraperitoneal AT, mainly omental and mesenteric AT, is the VAT component that most strongly links adiposity with adverse biological outcomes and morbidity. Intraperitoneal AT is not localized mainly at L4-L5, but at higher levels, and we have preliminary data suggesting other anatomic locations may be more strongly related to undesirable levels of metabolic measures. Moreover, total VAT includes multiple AT components and may not be the best marker of intraperitoneal AT or outcomes. To investigate these questions we propose to assemble and analyze the largest-to-date (~3000 scans) and most subject-diverse whole-body MRI database linked to associated body composition and laboratory studies. The pooled images and data will provide the needed initial data and rationale for expanding MRI studies into the emerging area of high-resolution image acquisition. It will also permit testing many other important hypotheses related to methods, model development and biological interests. Our findings could help to set new standards for VAT and adipose tissue subcompartment measurement, lower the cost of MRI body composition studies, and improve study power.