In vivo assessment of the ω-3 fatty acid fraction using 1H MR imaging at 3 Tesla

ω-3脂肪酸属于哺乳动物不能合成的必需脂肪酸，因此必须通过饮食获得。ω-3脂肪酸的代谢是高度关注的，因为其在代谢综合征的病理生理学背景中的作用尚未完全理解。以前研究ω-3脂肪酸在代谢综合征背景下的作用的研究主要基于血液样本和活检，因此无法深入了解ω-3脂肪酸水平的潜在器官和组织特异性模式。单体素1H磁共振波谱（MRS）和1H磁共振成像（MRI）是广泛可用的方法，其允许组织特性的非侵入性体内探测。虽然单体素MRS允许基于具有非常有限的空间信息的化学位移差异来获取具有高光谱分辨率的信号，但是MRI允许获得空间分辨的信息，但是由于光谱信息有限，需要先进的信号建模技术和先验知识来提取化学位移相关的特征。以前，已经有许多努力使用MRI来提取甘油三酯谱特征，其根据饱和、单不饱和和多不饱和脂肪酸的分数来描述脂肪酸组成。目前的项目提案旨在超越现有的指标，不仅对饱和、单不饱和和多不饱和脂肪酸组分的比例进行成像，而且还评估ω-3脂肪酸含量的比例，以进一步了解ω-3脂肪酸代谢。

ω-3 fatty acids belong to the group of essential fatty acids that mammals cannot synthesize and therefore have to be obtained through diet. The metabolism of ω-3 fatty acids is of high interest as its role is not completely understood in the pathophysiological context of the metabolic syndrome. Previous studies investigating the effects of ω-3 fatty acids in the context of the metabolic syndrome were predominantly based on blood samples and biopsies and were therefore not able to gain insights in the potential organ and tissue specific patterns of ω-3 fatty acids levels. Single-voxel 1H magnetic resonance spectroscopy (MRS) and 1H magnetic resonance imaging (MRI) are widely available methods that allow the non-invasive in vivo probing of tissue characteristics. While single-voxel MRS allows to acquire signals with high spectral resolution based on their chemical shift differences with very limited spatial information, MRI allows to obtain spatially-resolved information but requires advanced signal modeling techniques and prior knowledge to extract chemical shift-related characteristics due to limited spectral information. Previously, there have been many efforts using MRI to extract the triglyceride profile characteristics which describe the fatty acid composition in terms of the fraction of saturated, mono-unsaturated and poly-unsaturated fatty acids. The present project proposal is aiming for going beyond the existing metric aiming to image not only the fraction of saturated, mono-unsaturated and poly-unsaturated fatty acid fractions but also to assess the fraction of ω-3 fatty acid content to allow further insights into the ω-3 fatty acid metabolism.