Liver Imaging Group, Department of Radiology, University of California, San Diego School of Medicine, La Jolla, California, USA.
Computational and Applied Statistics Laboratory, San Diego Supercomputer Center, University of California, San Diego, La Jolla, California, USA.
J Magn Reson Imaging. 2019 Oct;50(4):1092-1102. doi: 10.1002/jmri.26671. Epub 2019 Jan 30.
Quantitative-chemical-shift-encoded (CSE)-MRI methods have been applied to the liver. The feasibility and potential utility CSE-MRI in monitoring changes in pancreatic proton density fat fraction (PDFF) have not yet been demonstrated.
To use quantitative CSE-MRI to estimate pancreatic fat changes during a weight-loss program in adults with severe obesity and nonalcoholic fatty liver disease (NAFLD). To explore the relationship of reduction in pancreatic PDFF with reductions in anthropometric indices.
Prospective/longitudinal.
Nine adults with severe obesity and NAFLD enrolled in a weight-loss program.
FIELD STRENGTH/SEQUENCE: CSE-MRI fat quantification techniques and multistation-volumetric fat/water separation techniques were performed at 3 T.
PDFF values were recorded from parametric maps colocalized across timepoints.
Rates of change of log-transformed variables across time were determined (linear-regression), and their significance assessed compared with no change (Wilcoxon test). Rates of change were correlated pairwise (Spearman's correlation).
Mean pancreatic PDFF decreased by 5.7% (range 0.7-17.7%) from 14.3 to 8.6%, hepatic PDFF by 11.4% (2.6-22.0%) from 14.8 to 3.4%, weight by 30.9 kg (17.3-64.2 kg) from 119.0 to 88.1 kg, body mass index by 11.0 kg/m (6.3-19.1 kg/m ) from 44.1 to 32.9 kg/m , waist circumference (WC) by 25.2 cm (4.0-41.0 cm) from 133.1 to 107.9 cm, HC by 23.5 cm (4.5-47.0 cm) from 135.8 to 112.3 cm, visceral adipose tissue (VAT) by 2.9 L (1.7-5.7 L) from 7.1 to 4.2 L, subcutaneous adipose tissue (SCAT) by 4.0 L (2.9-7.4 L) from 15.0 to 11.0 L. Log-transformed rate of change for pancreatic PDFF was moderately correlated with log-transformed rates for hepatic PDFF, VAT, SCAT, and WC (ρ = 0.5, 0.47, 0.45, and 0.48, respectively), although not statistically significant.
Changes in pancreatic PDFF can be estimated by quantitative CSE-MRI in adults undergoing a weight-loss surgery program. Pancreatic and hepatic PDFF and anthropometric indices decreased significantly.
2 Technical Efficacy Stage: 1 J. Magn. Reson. Imaging 2019;50:1092-1102.
定量化学位移编码（CSE）MRI 方法已应用于肝脏。CSE-MRI 在监测胰腺质子密度脂肪分数（PDFF）变化中的可行性和潜在应用尚未得到证实。
使用定量 CSE-MRI 估计严重肥胖和非酒精性脂肪性肝病（NAFLD）成人减肥计划中胰腺脂肪的变化。探讨胰腺 PDFF 减少与人体测量指标减少的关系。
前瞻性/纵向。
9 名患有严重肥胖和 NAFLD 的成年人参加了减肥计划。
场强/序列：在 3T 进行 CSE-MRI 脂肪定量技术和多站容积脂肪/水分离技术。
从时间点之间共定位的参数图记录 PDFF 值。
确定对数转换变量随时间的变化率（线性回归），并与无变化（Wilcoxon 检验）进行比较。变化率进行两两相关（Spearman 相关）。
从 14.3 到 8.6%，胰腺 PDFF 平均降低了 5.7%（范围为 0.7-17.7%）；从 14.8 到 3.4%，肝脏 PDFF 降低了 11.4%（范围为 2.6-22.0%）；体重从 119.0 到 88.1kg 减少了 30.9kg（范围为 17.3-64.2kg）；体重指数从 44.1 到 32.9kg/m 减少了 11.0kg/m（范围为 6.3-19.1kg/m）；腰围（WC）从 133.1 到 107.9cm 减少了 25.2cm（范围为 4.0-41.0cm）；髋围（HC）从 135.8 到 112.3cm 减少了 23.5cm（范围为 4.5-47.0cm）；内脏脂肪组织（VAT）从 7.1 到 4.2L 减少了 2.9L（范围为 1.7-5.7L）；皮下脂肪组织（SCAT）从 15.0 到 11.0L 减少了 4.0L（范围为 2.9-7.4L）。胰腺 PDFF 的对数转换变化率与肝脏 PDFF、VAT、SCAT 和 WC 的对数转换变化率中度相关（ρ=0.5、0.47、0.45 和 0.48），但无统计学意义。
通过接受减肥手术计划的成年人的定量 CSE-MRI 可以估计胰腺 PDFF 的变化。胰腺和肝脏 PDFF 以及人体测量指标均显著降低。
2 技术功效阶段：1 J. Magn. Reson. Imaging 2019;50:1092-1102.
