Department of Radiology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave, Ste ML5031, Cincinnati, OH 45229.
Department of Radiology, University of Cincinnati College of Medicine, Cincinnati, OH.
AJR Am J Roentgenol. 2024 Jul;223(1):e2431108. doi: 10.2214/AJR.24.31108. Epub 2024 Apr 17.
Liver fibrosis is an important clinical endpoint of the progression of autoimmune liver disease (AILD); its monitoring would benefit from noninvasive imaging tools. The purpose of this study was to assess the relationship between MR elastography (MRE) liver stiffness measurements and histologic liver fibrosis, as well as to evaluate the performance of MRE and biochemical-based clinical markers for stratifying histologic liver fibrosis severity, in children and young adults with AILD. This retrospective study used an existing institutional registry of children and young adults diagnosed with AILD (primary sclerosing cholangitis [PSC], autoimmune sclerosing cholangitis [ASC], or autoimmune hepatitis [AIH]). The registry was searched to identify patients who underwent both a research abdominal 1.5-T MRI examination that included liver MRE (performed for registry enrollment) and a clinically indicated liver biopsy within 6 months of that examination. MRE used a 2D gradient-recalled echo sequence. One analyst measured mean liver shear stiffness (in kilopascals) for each examination. Laboratory markers of liver fibrosis (aspartate aminotransferase-to-platelet ratio index [APRI] and fibrosis-4 [FIB-4] score) were recorded. For investigational purposes, one pathologist, blinded to clinical and MRI data, determined histologic Metavir liver fibrosis stage. The Spearman rank order correlation coefficient was calculated between MRE liver stiffness and Metavir liver fibrosis stage. ROC analysis was used to evaluate diagnostic performance for identifying advanced fibrosis (i.e., differentiating Metavir F0-F1 from F2-F4 fibrosis), and sensitivity and specificity were calculated using the Youden index. The study included 46 patients (median age, 16.6 years [IQR, 13.7-17.8 years]; 20 female patients, 26 male patients); 12 had PSC, 10 had ASC, and 24 had AIH. Median MRE liver stiffness was 2.9 kPa (IQR, 2.2-4.0 kPa). MRE liver stiffness and Metavir fibrosis stage showed strong positive correlation (ρ = 0.68). For identifying advanced liver fibrosis, MRE liver stiffness had an AUC of 0.81, with sensitivity of 65.4% and specificity of 90.0%; APRI had an AUC of 0.72, with sensitivity of 64.0% and specificity of 80.0%; and FIB-4 score had an AUC of 0.71, with sensitivity of 60.0% and specificity of 85.0%. MRE liver stiffness measurements were associated with histologic liver fibrosis severity. The findings support a role for MRE in noninvasive monitoring of liver stiffness, a surrogate for fibrosis, in children and young adults with AILD. ClinicalTrials.gov NCT03175471.
肝纤维化是自身免疫性肝病（AILD）进展的一个重要临床终点；对其进行监测将得益于非侵入性成像工具。本研究旨在评估磁共振弹性成像（MRE）肝脏硬度测量与组织学肝纤维化之间的关系，以及评估 MRE 和基于生化的临床标志物在儿童和青年 AILD 患者中对组织学肝纤维化严重程度进行分层的性能。这项回顾性研究使用了一个现有的机构登记处，登记处中包括了诊断为 AILD（原发性硬化性胆管炎[PSC]、自身免疫性硬化性胆管炎[ASC]或自身免疫性肝炎[AIH]）的儿童和青年患者。对登记处进行了检索，以确定在接受研究性腹部 1.5-T MRI 检查（包括 MRE 检查[用于登记处登记]）后 6 个月内进行了临床指示性肝活检的患者。MRE 使用 2D 梯度回波序列。一位分析师为每次检查测量平均肝脏剪切硬度（以千帕斯卡为单位）。记录了肝脏纤维化的实验室标志物（天门冬氨酸氨基转移酶-血小板比值指数[APRI]和纤维化-4[FIB-4]评分）。出于研究目的，一位病理学家在不了解临床和 MRI 数据的情况下确定了组织学梅特维尔肝纤维化分期。计算 MRE 肝脏硬度与梅特维尔肝纤维化分期之间的 Spearman 秩相关系数。使用 ROC 分析评估了识别晚期纤维化（即，区分梅特维尔 F0-F1 与 F2-F4 纤维化）的诊断性能，并使用约登指数计算了敏感性和特异性。该研究包括 46 名患者（中位数年龄，16.6 岁[IQR，13.7-17.8 岁]；20 名女性患者，26 名男性患者）；12 名患者患有 PSC，10 名患者患有 ASC，24 名患者患有 AIH。MRE 肝脏硬度中位数为 2.9kPa（IQR，2.2-4.0kPa）。MRE 肝脏硬度和梅特维尔纤维化分期显示出强烈的正相关（ρ=0.68）。对于识别晚期肝纤维化，MRE 肝脏硬度的 AUC 为 0.81，敏感性为 65.4%，特异性为 90.0%；APRI 的 AUC 为 0.72，敏感性为 64.0%，特异性为 80.0%；FIB-4 评分的 AUC 为 0.71，敏感性为 60.0%，特异性为 85.0%。MRE 肝脏硬度测量与组织学肝纤维化严重程度相关。这些发现支持 MRE 在儿童和青年 AILD 患者中对纤维化替代物肝脏硬度进行非侵入性监测中的作用。ClinicalTrials.gov NCT03175471。
