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感兴趣的，因为它在代谢综合征的病理生理背景下的作用尚未完全理解。之前关于ω-3脂肪酸对代谢综合征影响的研究主要基于血液样本和活组织检查，因此无法深入了解ω-3脂肪酸水平的潜在器官和组织特定模式。单体素1H磁共振波谱（MRS）和1H磁共振成像（MRI）是广泛使用的方法，可以对组织特征进行非侵入性体内探测。单体素MRS可以在非常有限的空间信息下，基于化学位移差异获得高光谱分辨率的信号，而MRI可以获得空间分辨率的信息，但由于光谱信息有限，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特征。以前，已经有许多努力使用MRI提取甘油三酯剖面特征，描述脂肪酸组成方面的饱和，单不饱和和多不饱和脂肪酸的比例。目前的项目提案旨在超越现有的度量，旨在不仅成像饱和，单不饱和和多不饱和脂肪酸部分的分数，而且还评估ω-3脂肪酸含量的分数，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.