Middleton Michael S, Haufe William, Hooker Jonathan, Borga Magnus, Dahlqvist Leinhard Olof, Romu Thobias, Tunón Patrik, Hamilton Gavin, Wolfson Tanya, Gamst Anthony, Loomba Rohit, Sirlin Claude B
From the Liver Imaging Group, Department of Radiology (M.S.M., W.H., J.H., G.H., C.B.S.), Computational and Applied Statistics Laboratory, San Diego Supercomputing Center (T.W., A.G.), and Department of Medicine, Division of Gastroenterology and Hepatology (R.L.), University of California, San Diego, 9500 Gilman Dr, MC 0888, San Diego, CA 92093-0888; Advanced MR Analytics AB, Linköping, Sweden (M.B., O.D.L., T.R., P.T.); and Center for Medical Image Science and Visualization (M.B., O.D.L., T.R.), Department of Biomedical Engineering (M.B., T.R.), and Department of Medicine and Health (O.D.L.), Linköping University, Linköping, Sweden.
Radiology. 2017 May;283(2):438-449. doi: 10.1148/radiol.2017160606. Epub 2017 Mar 9.
Purpose To determine the repeatability and accuracy of a commercially available magnetic resonance (MR) imaging-based, semiautomated method to quantify abdominal adipose tissue and thigh muscle volume and hepatic proton density fat fraction (PDFF). Materials and Methods This prospective study was institutional review board- approved and HIPAA compliant. All subjects provided written informed consent. Inclusion criteria were age of 18 years or older and willingness to participate. The exclusion criterion was contraindication to MR imaging. Three-dimensional T1-weighted dual-echo body-coil images were acquired three times. Source images were reconstructed to generate water and calibrated fat images. Abdominal adipose tissue and thigh muscle were segmented, and their volumes were estimated by using a semiautomated method and, as a reference standard, a manual method. Hepatic PDFF was estimated by using a confounder-corrected chemical shift-encoded MR imaging method with hybrid complex-magnitude reconstruction and, as a reference standard, MR spectroscopy. Tissue volume and hepatic PDFF intra- and interexamination repeatability were assessed by using intraclass correlation and coefficient of variation analysis. Tissue volume and hepatic PDFF accuracy were assessed by means of linear regression with the respective reference standards. Results Adipose and thigh muscle tissue volumes of 20 subjects (18 women; age range, 25-76 years; body mass index range, 19.3-43.9 kg/m) were estimated by using the semiautomated method. Intra- and interexamination intraclass correlation coefficients were 0.996-0.998 and coefficients of variation were 1.5%-3.6%. For hepatic MR imaging PDFF, intra- and interexamination intraclass correlation coefficients were greater than or equal to 0.994 and coefficients of variation were less than or equal to 7.3%. In the regression analyses of manual versus semiautomated volume and spectroscopy versus MR imaging, PDFF slopes and intercepts were close to the identity line, and correlations of determination at multivariate analysis (R) ranged from 0.744 to 0.994. Conclusion This MR imaging-based, semiautomated method provides high repeatability and accuracy for estimating abdominal adipose tissue and thigh muscle volumes and hepatic PDFF. RSNA, 2017.
目的 确定一种基于磁共振（MR）成像的商用半自动方法在量化腹部脂肪组织、大腿肌肉体积和肝脏质子密度脂肪分数（PDFF）方面的重复性和准确性。材料与方法 本前瞻性研究经机构审查委员会批准且符合健康保险流通与责任法案（HIPAA）规定。所有受试者均提供了书面知情同意书。纳入标准为年龄在18岁及以上且愿意参与。排除标准为存在MR成像禁忌证。采集三维T1加权双回波体线圈图像3次。对源图像进行重建以生成水图像和校准脂肪图像。采用半自动方法并以手动方法作为参考标准对腹部脂肪组织和大腿肌肉进行分割，并估计其体积。采用校正混杂因素的化学位移编码MR成像方法并以磁共振波谱作为参考标准估计肝脏PDFF。通过组内相关分析和变异系数分析评估组织体积和肝脏PDFF在检查内和检查间的重复性。通过与各自参考标准进行线性回归评估组织体积和肝脏PDFF的准确性。结果 采用半自动方法对20名受试者（18名女性；年龄范围25 - 76岁；体重指数范围19.3 - 43.9 kg/m²）的脂肪和大腿肌肉组织体积进行了估计。检查内和检查间的组内相关系数为0.996 - 0.998，变异系数为1.5% - 3.6%。对于肝脏MR成像PDFF，检查内和检查间的组内相关系数大于或等于0.99４，变异系数小于或等于7.3%。在手动与半自动体积以及磁共振波谱与MR成像的回归分析中，PDFF的斜率和截距接近恒等线，多变量分析时的决定系数（R）范围为0.744至0.994。结论 这种基于MR成像的半自动方法在估计腹部脂肪组织、大腿肌肉体积和肝脏PDFF方面具有高重复性和准确性。RSNA，2017年。
