Joint Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.
Department of Pathology, University Health Network, University of Toronto, Toronto, Ontario, Canada.
Liver Transpl. 2018 Apr;24(4):470-477. doi: 10.1002/lt.24965. Epub 2018 Mar 6.
The purpose of this study is to determine whether magnetic resonance (MR)-proton density fat fraction (PDFF) estimate of negligible hepatic fat percentage (<5%) can exclude significant hepatic steatosis (≥10%) in living liver donor candidates obviating the need for liver biopsy and to perform intraindividual comparisons between MR-PDFF techniques for hepatic steatosis quantification. In an ethics-approved retrospective study, 144 liver donor candidates with magnetic resonance spectroscopy (MRS) and 6-echo Dixon magnetic resonance imaging (MRI) between 2013 and 2015 were included. A subset of 32 candidates underwent liver biopsy. Hepatic fat percentage was determined using MR-PDFF and histopathology-determined fat fraction as the reference standard. A receiver operating characteristic analysis with positive predictive value, negative predictive value (NPV), sensitivity, and specificity was performed to discriminate between clinically significant steatosis (≥10%) or not (<10%) at MRS-PDFF and MRI-PDFF thresholds of 5% and 10%. Pearson correlation and Bland-Altman analyses between MRS-PDFF and MRI-PDFF were performed for intraindividual comparison of hepatic steatosis estimation. There was significant association between MRS-PDFF and MRI-PDFF with HP-FP. High NPV of 95% (95% confidence interval [CI], 78%-99%) and 100% (95% CI, 76%-100%) as well as an area under the curve of 0.90 (95% CI, 0.79-1.0) and 0.93 (95% CI, 0.84-1.0) were obtained with a cutoff threshold of 5% MRI-PDFF and MRS-PDFF, respectively, to exclude clinically significant steatosis (≥10%). Intraindividual comparison between MRS-PDFF and MRI-PDFF showed a Pearson correlation coefficient of 0.83. Bland-Altman analysis showed a mean difference of 1% with 95% limits of agreement between -1% and 3%. MR-PDFF estimate of negligible hepatic fat percentage (<5%) has sufficient NPV for excluding clinically significant hepatic steatosis (≥10%) in living liver donor candidates obviating the need for liver biopsy. It may be sufficient to acquire only the multiecho Dixon MRI-PDFF for hepatic steatosis estimation. Liver Transplantation 24 470-477 2018 AASLD.
本研究旨在确定磁共振质子密度脂肪分数(PDFF)估计值<5%的肝脏脂肪含量可忽略不计能否排除活体肝供者候选者的显著肝脂肪变性(≥10%),从而避免肝活检的需要,并对磁共振 PDFF 技术进行肝脂肪变性定量的个体内比较。在一项经伦理批准的回顾性研究中,纳入了 2013 年至 2015 年间接受磁共振波谱(MRS)和 6 回波 Dixon 磁共振成像(MRI)检查的 144 名肝供者候选者。其中一组 32 名候选者接受了肝活检。使用磁共振 PDFF 和组织病理学确定的脂肪分数作为参考标准,确定肝脂肪百分比。在 MRS-PDFF 和 MRI-PDFF 阈值为 5%和 10%时,对临床显著脂肪变性(≥10%)或无脂肪变性(<10%)进行受试者工作特征分析,计算阳性预测值、阴性预测值(NPV)、敏感性和特异性,以区分两者。对 MRS-PDFF 和 MRI-PDFF 进行 Pearson 相关性和 Bland-Altman 分析,以进行肝脂肪变性估计的个体内比较。MRS-PDFF 与 HP-FP 呈显著相关性。当 MRI-PDFF 和 MRS-PDFF 的截断值分别为 5%和 5%时,具有 95%(95%置信区间 [CI],78%-99%)和 100%(95%CI,76%-100%)的高 NPV 以及 0.90(95%CI,0.79-1.0)和 0.93(95%CI,0.84-1.0)的曲线下面积,可排除临床显著脂肪变性(≥10%)。MRS-PDFF 和 MRI-PDFF 之间的个体内比较显示 Pearson 相关系数为 0.83。Bland-Altman 分析显示平均差值为 1%,95%的一致性界限为-1%至 3%。磁共振 PDFF 估计肝脏脂肪含量<5%,对排除活体肝供者候选者的临床显著肝脂肪变性(≥10%)具有足够的 NPV,从而避免了肝活检的需要。对于肝脂肪变性的估计,仅获取多回波 Dixon MRI-PDFF 可能就足够了。《肝脏病学》24 470-477 2018 AASLD。