Biomedical Engineering, University of Virginia, Charlottesville, VA.
Biomedical, Biological & Chemical Engineering, University of Missouri, Columbia, MO.
Magn Reson Med. 2022 Oct;88(4):1734-1747. doi: 10.1002/mrm.29348. Epub 2022 Jun 20.
To develop an accelerated MRI method to quantify the epicardial adipose tissue (EAT) fatty acid composition (FAC) and test the hypothesis that eplerenone (EPL) shifts the EAT FAC toward unsaturation in obese mice.
Undersampled multi-echo gradient echo imaging employing a dictionary-based compressed-sensing reconstruction and iterative decomposition with echo asymmetry and least-squares-based mapping (IDEAL) was developed, validated, and used to study EAT in obese mice scanned at 7T. Fully sampled and rate 2, 2.5, 3, and 3.5 undersampled image data were acquired, reconstructed, and assessed using RMSE and structural similarity (SSIM). Two groups of mice were studied: untreated (control, n = 10) and EPL-treated (n = 10) mice fed a high-fat high-sucrose diet. MRI included imaging of EAT FAC, EAT volume, and myocardial perfusion reserve.
Rate 3 acceleration provided RMSE <5% and structural similarity >0.85 for FAC MRI. After 6 weeks of diet, EPL-treated compared to untreated mice had a reduced EAT saturated fatty acid fraction (0.27 ± 0.09 vs. 0.39 ± 0.07, P < 0.05) and increased EAT unsaturation degree (4.37 ± 0.32 vs. 3.69 ± 0.58, P < 0.05). Also, EAT volume in EPL-treated compared to untreated mice was reduced (8.1 ± 0.6 mg vs. 11.4 ± 0.7 mg, P < 0.01), and myocardial perfusion reserve was improved (1.83 ± 0.15 vs. 1.61 ± 0.17, P < 0.05).
Rate 3 accelerated FAC MRI enabled accurate quantification of EAT FAC in mice. EPL treatment shifted the EAT FAC toward increased unsaturation and was associated with improvement of coronary microvascular function.
开发一种加速 MRI 方法来定量测量心外膜脂肪组织 (EAT) 的脂肪酸组成 (FAC)，并验证依普利酮 (EPL) 是否能使肥胖小鼠的 EAT FAC 向不饱和方向转变。
采用基于字典的压缩感知重建和具有回声不对称和基于最小二乘的映射的迭代分解 (IDEAL) 的欠采样多回波梯度回波成像进行开发和验证，并用于在 7T 下扫描肥胖小鼠的 EAT。采集、重建和评估完全采样和速率 2、2.5、3 和 3.5 欠采样的图像数据，使用均方根误差 (RMSE) 和结构相似性 (SSIM) 进行评估。研究了两组小鼠：未治疗（对照组，n=10）和依普利酮治疗（n=10）的高脂肪高蔗糖饮食喂养的小鼠。MRI 包括 EAT FAC、EAT 体积和心肌灌注储备的成像。
速率 3 加速提供了 FAC MRI 的 RMSE<5%和结构相似性>0.85。在 6 周饮食后，与未治疗组相比，依普利酮治疗组的 EAT 饱和脂肪酸分数降低（0.27±0.09 比 0.39±0.07，P<0.05），EAT 不饱和程度增加（4.37±0.32 比 3.69±0.58，P<0.05）。此外，与未治疗组相比，依普利酮治疗组的 EAT 体积减少（8.1±0.6 mg 比 11.4±0.7 mg，P<0.01），心肌灌注储备改善（1.83±0.15 比 1.61±0.17，P<0.05）。
速率 3 加速的 FAC MRI 能够准确量化小鼠的 EAT FAC。EPL 治疗使 EAT FAC 向不饱和方向转变，并与改善冠状动脉微血管功能有关。
