锁骨上棕色脂肪组织的 MRI 特征与健康成年人冷诱导产热的关系。
MRI characteristics of supraclavicular brown adipose tissue in relation to cold-induced thermogenesis in healthy human adults.
机构信息
Department of Endocrinology, Diabetes and Metabolism, University Hospital of Basel and University of Basel, Basel, Switzerland.
Department of Radiology, University Hospital of Basel and University of Basel, Basel, Switzerland.
出版信息
J Magn Reson Imaging. 2019 Oct;50(4):1160-1168. doi: 10.1002/jmri.26733. Epub 2019 Apr 4.
BACKGROUND
Brown adipose tissue (BAT) has been proposed as a target to treat obesity and metabolic disease. Currently, F-Fluordeoxyglucose positron emission tomography (FDG-PET) is the standard for BAT-imaging. MRI might be a promising alternative, as it is not associated with ionizing radiation, offers a high resolution, and allows to discriminate different types of soft tissue.
PURPOSE
We sought to evaluate whether supraclavicular BAT (scBAT) volume, fat-fraction (FF), and relaxation rate (R2*) determined by MRI can predict its metabolic activity, which was assessed by measurement of cold-induced thermogenesis (CIT).
STUDY TYPE
Prospective cohort study.
SUBJECTS
Twenty healthy volunteers (9 female, 11 male), aged 18-47 years, with a body mass index (BMI) of 18-30 kg/m .
FIELD STRENGTH/SEQUENCE: Multiecho gradient MRI for water-fat separation was used on a 3T device to measure the FF and T * of BAT.
ASSESSMENT
Prior to imaging, CIT was determined by measuring the difference in energy expenditure (EE) during warm conditions and after cold exposure. Volume, FF, and R2* of scBAT was assessed and compared with CIT. In 11 participants, two MRI sessions with and without cold exposure were performed and the dynamic changes in FF and R2* assessed.
STATISTICAL TESTS
Linear regression was used to evaluate the relation of MRI measurements and CIT. P-values below 0.05 were considered significant; data are given as mean ± SD.
RESULTS
R2* correlated positively with CIT (r = 0.64, R = 0.41 P = 0.0041). Volume and FF did not correlate significantly with CIT. After mild cold exposure EE increased significantly (P = 0.0002), with a mean CIT of 147 kcal/day. The mean volume of scBAT was 72.4 ± 38.4 ml, mean FF was 74.3 ± 5.8%, and the mean R2* (1/T *) was 33.5 ± 12.7 s .
DATA CONCLUSION
R2* of human scBAT can be used to estimate CIT. FF of scBAT was not associated with CIT.
LEVEL OF EVIDENCE
2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1160-1168.
背景
棕色脂肪组织（BAT）已被提议作为治疗肥胖和代谢疾病的靶点。目前，18F-氟脱氧葡萄糖正电子发射断层扫描（FDG-PET）是 BAT 成像的标准。磁共振成像（MRI）可能是一种很有前途的替代方法，因为它不与电离辐射有关，具有较高的分辨率，并允许区分不同类型的软组织。
目的
我们旨在评估 MRI 测定的锁骨上 BAT（scBAT）体积、脂肪分数（FF）和弛豫率（R2*）是否可以预测其代谢活性，代谢活性通过冷诱导产热（CIT）测量来评估。
研究类型
前瞻性队列研究。
受试者
20 名健康志愿者（9 名女性，11 名男性），年龄 18-47 岁，体重指数（BMI）为 18-30 kg/m 。
磁场强度/序列：使用 3T 设备上的多回波梯度 MRI 进行水-脂分离，以测量 BAT 的 FF 和 T*。
评估
在成像之前，通过测量温暖条件下和冷暴露后的能量消耗（EE）差异来确定 CIT。评估并比较 scBAT 的体积、FF 和 R2*。在 11 名参与者中，进行了两次带有和不带有冷暴露的 MRI 检查，并评估了 FF 和 R2*的动态变化。
统计学检验
使用线性回归评估 MRI 测量值与 CIT 的关系。P 值低于 0.05 被认为具有统计学意义；数据以平均值±标准差表示。
结果
R2与 CIT 呈正相关（r = 0.64，R = 0.41，P = 0.0041）。体积和 FF 与 CIT 无显著相关性。轻度冷暴露后，EE 显著增加（P = 0.0002），平均 CIT 为 147 kcal/天。scBAT 的平均体积为 72.4±38.4ml，平均 FF 为 74.3±5.8%，平均 R2（1/T*）为 33.5±12.7 s。
数据结论
人体 scBAT 的 R2*可用于估计 CIT。scBAT 的 FF 与 CIT 无关。
证据水平
2 级技术功效：2 期 J. Magn. Reson. Imaging 2019;50:1160-1168.
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