Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Chuo-ku, Kumamoto, 860-8556, Japan.
Eur Radiol. 2021 Aug;31(8):5779-5790. doi: 10.1007/s00330-021-07706-2. Epub 2021 Mar 25.
To evaluate the ability of iodine uptake parameters from hepatic multiphasic CT to predict liver fibrosis, and compare absolute contrast enhancement (ΔHU) with dual-energy iodine density (ID) methods.
One hundred seventeen patients with pathologically proven liver fibrosis who underwent dual-energy CT during portal-venous phase (PVP) and 3-min delayed phase (DP) between January 2017 and Octotber 2019 were retrospectively included. Two radiologists measured the hepatic and blood-pool iodine uptake using ΔHU and ID methods; extracellular volume fraction (ECV) and the iodine washout rate (IWR) calculated with both methods were compared between different fibrosis stages (F0-1 vs. F2-4, F0-2 vs. F3-4, or F0-3 vs. F4). The inter-observer reproducibility (intraclass correlation coefficients [ICCs]) for ECV and IWR was compared between the ΔHU and ID methods. The areas under the receiver operating characteristic curves (AUCs) to predict liver fibrosis severity were calculated for serum and imaging fibrosis markers. To identify independent predictors, multivariable logistic regression analysis was performed, and combined performance was assessed for the ΔHU and ID models.
Patients with F ≥ 2 (n = 70), F ≥ 3 (n = 51), and F4 (n = 29) had higher ECV and lower IWR than those with F ≤ 1, F ≤ 2, and F ≤ 3, respectively (all p < 0.001). ICCs were higher in the ID method than in the ΔHU method (ECV: p = 0.045; IWR: p < 0.001). The AUC ranges of ECV, ECV, IWR, and IWR for predicting liver fibrosis severity were 0.65-0.71, 0.67-0.73, 0.76-0.81, and 0.81-0.85, respectively. IWR and fibrosis-4 index were independent predictors, with combined AUCs of 0.82-0.87 for the ΔHU model and 0.86-0.89 for the ID model.
IWR more accurately predicted liver fibrosis than ECV in routine multiphasic CT. The dual-energy ID method yielded higher inter-observer reproducibility and predictive values than the single-energy ΔHU method.
• The IWR calculated from hepatic iodine uptake during PVP and 3-min DP predicted liver fibrosis (AUC, 0.76-0.85), while the ECV had a relatively limited predictive value (ACU, 0.65-0.73). • Compared with the conventional ΔHU method, the dual-energy ID method provided superior inter-observer reproducibility for measurement of ECV (p = 0.046) and IWR (p < 0.001). • The IWR and FIB-4 served as independent predictors of liver fibrosis; their combination yielded the high diagnostic performance particularly when using the ID method (combined AUCs of 0.86-0.89).
评估肝多期 CT 碘摄取参数预测肝纤维化的能力，并比较绝对对比增强（ΔHU）与双能量碘密度（ID）方法。
回顾性纳入了 2017 年 1 月至 2019 年 10 月期间在门静脉期（PVP）和 3 分钟延迟期（DP）行双能 CT 的 117 例经病理证实的肝纤维化患者。两名放射科医生使用 ΔHU 和 ID 方法测量肝脏和血池碘摄取；比较不同纤维化阶段（F0-1 与 F2-4、F0-2 与 F3-4 或 F0-3 与 F4）之间的细胞外容积分数（ECV）和碘洗脱率（IWR）。比较了 ΔHU 和 ID 方法之间 ECV 和 IWR 的观察者间可重复性（组内相关系数 [ICC]）。计算了血清和成像纤维化标志物预测肝纤维化严重程度的受试者工作特征曲线下面积（AUC）。为了确定独立预测因子，进行了多变量逻辑回归分析，并评估了 ΔHU 和 ID 模型的联合性能。
F≥2（n=70）、F≥3（n=51）和 F4（n=29）患者的 ECV 较高，IWR 较低，与 F≤1、F≤2 和 F≤3 患者相比，差异均有统计学意义（均 P＜0.001）。ID 方法的 ICC 高于 ΔHU 方法（ECV：P=0.045；IWR：P＜0.001）。ECV、ECV、IWR 和 IWR 预测肝纤维化严重程度的 AUC 范围分别为 0.65-0.71、0.67-0.73、0.76-0.81 和 0.81-0.85。IWR 和纤维化-4 指数是独立的预测因子，ΔHU 模型的 AUC 为 0.82-0.87，ID 模型的 AUC 为 0.86-0.89。
与 ECV 相比，IWR 更能准确预测肝纤维化。与单能量 ΔHU 方法相比，双能量 ID 方法具有更高的观察者间可重复性和预测值。
在常规多期 CT 中，通过门静脉期和 3 分钟 DP 期间肝脏碘摄取计算出的 IWR 预测了肝纤维化（AUC 为 0.76-0.85），而 ECV 的预测价值相对有限（AUC 为 0.65-0.73）。
与传统的 ΔHU 方法相比，双能量 ID 方法为 ECV（p=0.046）和 IWR（p＜0.001）的测量提供了更好的观察者间可重复性。
IWR 和 FIB-4 是肝纤维化的独立预测因子；当使用 ID 方法时，它们的组合可获得较高的诊断性能（联合 AUC 为 0.86-0.89）。
