Department of Radiology, The Second Xiangya Hospital of Central South University, Changsha, China.
MR Collaboration, Central Research Institute, United Imaging Healthcare, Shanghai, China.
J Magn Reson Imaging. 2022 Jun;55(6):1864-1874. doi: 10.1002/jmri.27925. Epub 2021 Sep 21.
Partial bile duct ligation (PBDL) model is a reliable cholestatic fibrosis experimental model that showed complex histopathological changes. Magnetic resonance imaging (MRI) features of PBDL have not been well characterized.
To investigate the potential of MRI parameters in assessing fibrosis in PBDL and explore the relationships between MRI and pathological features.
Established PBDL models.
Fifty-four mice were randomly divided into four timepoints PBDL groups and one sham group.
FIELD STRENGTH/SEQUENCE: 3.0 T; MRI sequences included T1-weighted fast spin-echo (FSE), T2-weighted single shot FSE, variable flip angle T1 mapping, multi-echo SE T2 mapping, multi-echo gradient-echo T2* mapping, and multi-b-value diffusion-weighted imaging.
MRI examination was performed at the corresponding timepoints after surgery. Native T1, ΔT1 (T1native-T1post), T2, T2*, apparent diffusion coefficient (ADC) values, histogram parameters (skewness and kurtosis), intravoxel incoherent motion parameters (f, D, and D ) within the entire ligated (PBDL), non-ligated liver (PBDL), and whole liver (sham) were obtained. Fibrosis and inflammation were assessed in Masson and H&E staining slices using the Metavir and activity scoring system.
One-way ANOVA, Spearman's rank correlation, and receiver operating characteristic curves were performed. P < 0.05 was considered statistically significant.
Fibrosis and inflammation were finally staged as F3 and A3 in ligated livers but were not observed in non-ligated or sham livers. Ligated livers displayed significantly elevated native T1, ΔT1, T2, and reduced ADC and T2 than other livers. Spearman's correlation showed better correlation with inflammation (r = 0.809) than fibrosis (r = 0.635) in T2 and both ΔT1 and ADC showed stronger correlation with fibrosis (r = 0.704 and r = -0.718) than inflammation (r = 0.564 and r = -0.550). Area under the curve (AUC) for ΔT1 performed the highest (0.896). When combined with all relative parameters, AUC increased to 0.956.
Multiparametric MRI can evaluate and differentiate pathological changes in PBDL. ΔT1 and ADC better correlated with fibrosis while T2 stronger with inflammation.
1 TECHNICAL EFFICACY: Stage 2.
部分胆管结扎（PBDL）模型是一种可靠的胆汁淤积性纤维化实验模型，显示出复杂的组织病理学变化。PBDL 的磁共振成像（MRI）特征尚未得到很好的描述。
探讨 MRI 参数在评估 PBDL 纤维化中的潜力，并探索 MRI 与病理特征之间的关系。
建立 PBDL 模型。
54 只小鼠随机分为 4 个 PBDL 组和 1 个假手术组。
磁场强度/序列：3.0T；MRI 序列包括 T1 加权快速自旋回波（FSE）、T2 加权单次激发 FSE、可变翻转角 T1 映射、多回波 SE T2 映射、多回波梯度回波 T2*映射和多 b 值扩散加权成像。
术后相应时间点进行 MRI 检查。获得结扎（PBDL）、未结扎（PBDL）和整个肝脏（假手术）的原始 T1、ΔT1（T1native-T1post）、T2、T2*、表观扩散系数（ADC）值、直方图参数（偏度和峰度）、体素内不相干运动参数（f、D 和 D）。使用 Metavir 和活动评分系统在 Masson 和 H&E 染色切片中评估纤维化和炎症。
进行单因素方差分析、Spearman 秩相关和受试者工作特征曲线分析。P<0.05 被认为具有统计学意义。
结扎肝脏最终被分期为 F3 和 A3，但在未结扎或假手术肝脏中未观察到。结扎肝脏的原始 T1、ΔT1、T2 显著升高，ADC 降低，T2 降低。Spearman 相关性显示 T2 与炎症的相关性更好（r=0.809），与纤维化的相关性（r=0.635），而 ΔT1 和 ADC 与纤维化的相关性更强（r=0.704 和 r=-0.718），与炎症的相关性（r=0.564 和 r=-0.550）。ΔT1 的曲线下面积（AUC）最高（0.896）。当与所有相对参数结合时，AUC 增加到 0.956。
多参数 MRI 可用于评估和区分 PBDL 的病理变化。ΔT1 和 ADC 与纤维化的相关性更好，而 T2 与炎症的相关性更强。
1 技术功效：第 2 阶段。
