南方医科大学学报 ›› 2021, Vol. 41 ›› Issue (5): 783-788.doi: 10.12122/j.issn.1673-4254.2021.05.21

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1H-MRS、Dixon水脂分离与Z谱成像技术在大鼠棕色脂肪上的量化比较

蔡子萌,易佩伟,陶 泉,冯衍秋   

  • 出版日期:2021-05-20 发布日期:2021-06-11

Comparison of 1H-MRS, Dixon fat-water separation and Z-spectral imaging for quantification of brown adipose tissue in rats

  • Online:2021-05-20 Published:2021-06-11

摘要: 目的 比较1H-MRS、Dixon水脂分离与Z谱成像技术在体模以及大鼠棕色脂肪上的脂肪量化结果。方法 首先,制作6个脂肪含量分别为0%、20%、40%、60%、80%、100%的油水混合体模,共同放置于50 mL离心管内。依次采用ZS-MRI、1H-MRS和Dixon水脂分离技术对体模的脂肪含量进行定量评估,其结果与体模脂肪真实值相比较。其次,使用ZS-MRI和Dixon水脂分离技术分别采集了六只大鼠肩胛间的数据,并计算出水脂分布图,并将结果与1H-MRS定量结果进行比较。结果 ZS-MRI可以很好地准确定量并区分出各个不同脂肪含量的体模(Y=0.95*X+1.48);能较好地区分棕色脂肪与白色脂肪,并与Dixon方法得到的脂肪含量在空间分布上高度一致。在棕色脂肪的量化上,ZS-MRI结果 与1H-MRS结果相比无显著性差异(P=0.35)。结论 ZS-MRI作为一种新的脂肪定量方法,可以生成无伪影的脂肪分布图,用于定量测量大鼠体内棕色脂肪的含量以及分布。

关键词: 棕色脂肪;脂肪含量;磁共振波谱分析技术;Dixon水脂分离技术;Z谱成像技术

Abstract: Objective To evaluate the performance of 1H-magnetic resonance spectroscopy (1H-MRS), Dixon fat-water separation and Z-spectral magnetic resonance imaging (ZS-MRI) for quantification of fat content in phantoms and brown adipose tissues in rats. Methods First, six water-oil mixture phantoms with different fat fractions (0, 20%, 40%, 60%, 80% and 100% ) were prepared and placed in a 50-mL centrifuge tube. ZS-MRI, 1H-MRS and Dixon's method were used to quantitatively evaluate the fat content of the phantom, and the results were compared against the actual fat fractions. Then, ZS-MRI and Dixon's method were used to collect the data in the interscapular region of 6 rats, the fat-water distribution map was calculated, and the results were compared with 1 H-MRS. Results ZS-MRI accurately quantified fat contents in the phantoms (Y=0.95*X+1.48). ZS-MRI was capable of distinguishing brown adipose tissue from white adipose tissue and defining the spatial distribution of the adipose tissue, and the results were highly consistent with those obtained by Dixon's method. No significant differences were found in the results derived by ZS-MRI and 1H-MRS for quantification of brown adipose tissue (P=0.35). ConclusionZS-MRI can generate an artifact-free fat distribution map for quantitative measurement of the content and distribution of brown adipose tissues in rats.

Key words: brown adipose tissue; fat content; 1H-magnetic resonance spectroscopy; Dixon fat-water separation technology; Z-spectral magnetic resonance imaging