Department of Radiology, West China Hospital, Sichuan University, 37# Guoxue Road, Chengdu, Sichuan, China.
Department of Radiology, The First Affiliated Hospital of Chengdu Medical College, 278# Baoguang Road, Xindu District, Chengdu, Sichuan, China.
Abdom Radiol (NY). 2017 Dec;42(12):2855-2863. doi: 10.1007/s00261-017-1208-2.
To retrospectively determine the feasibility of intravoxel incoherent motion (IVIM) imaging based on histogram analysis for the staging of liver fibrosis (LF) using histopathologic findings as the reference standard.
56 consecutive patients (14 men, 42 women; age range, 15-76, years) with chronic liver diseases (CLDs) were studied using IVIM-DWI with 9 b-values (0, 25, 50, 75, 100, 150, 200, 500, 800 s/mm) at 3.0 T. Fibrosis stage was evaluated using the METAVIR scoring system. Histogram metrics including mean, standard deviation (Std), skewness, kurtosis, minimum (Min), maximum (Max), range, interquartile (Iq) range, and percentiles (10, 25, 50, 75, 90th) were extracted from apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f) maps. All histogram metrics among different fibrosis groups were compared using one-way analysis of variance or nonparametric Kruskal-Wallis test. For significant parameters, receivers operating characteristic curve (ROC) analyses were further performed for the staging of LF.
Based on their METAVIR stage, the 56 patients were reclassified into three groups as follows: F0-1 group (n = 25), F2-3 group (n = 21), and F4 group (n = 10). The mean, Iq range, percentiles (50, 75, and 90th) of D* maps between the groups were significant differences (all P < 0.05). Area under the ROC curve (AUC) of the mean, Iq range, 50, 75, and 90th percentile of D* maps for identifying significant LF (≥F2 stage) was 0.901, 0.859, 0.876, 0.943, and 0.886 (all P < 0.0001), respectively; for diagnosing severe fibrosis or cirrhosis (F4), AUC was 0.917, 0.922, 0.943, 0.985, and 0.939 (all P < 0.0001), respectively. The histogram metrics of ADC, D, and f maps demonstrated no significant difference among the groups (all P > 0.05).
Histogram analysis of D* map derived from IVIM can be used to stage liver fibrosis in patients with CLDs and provide more quantitative information beyond the mean value.
回顾性分析基于体素内不相干运动（IVIM）成像直方图分析对肝脏纤维化（LF）分期的可行性，以组织病理学发现为参考标准。
对 56 例连续的慢性肝病（CLD）患者（14 名男性，42 名女性；年龄范围 15-76 岁）进行 3.0T 下的 IVIM-DWI 9 个 b 值（0、25、50、75、100、150、200、500、800s/mm）扫描。采用 METAVIR 评分系统评估纤维化分期。从表观扩散系数（ADC）、真实扩散系数（D）、假性扩散系数（D*）和灌注分数（f）图中提取平均、标准差（Std）、偏度、峰度、最小值（Min）、最大值（Max）、范围、四分位数间距（Iq）和百分位数（10、25、50、75、90 位）等直方图指标。采用单因素方差分析或非参数 Kruskal-Wallis 检验比较不同纤维化组间的所有直方图指标。对有统计学意义的参数，进一步进行受试者工作特征曲线（ROC）分析，以评估 LF 的分期。
根据 METAVIR 分期，56 例患者被重新分为三组：F0-1 组（n=25）、F2-3 组（n=21）和 F4 组（n=10）。D图的平均、Iq 范围、50、75 和 90 位百分位数在组间有显著差异（均 P<0.05）。D图的平均、Iq 范围、50、75 和 90 位百分位数对识别有意义的 LF（≥F2 期）的 ROC 曲线下面积（AUC）分别为 0.901、0.859、0.876、0.943 和 0.886（均 P<0.0001）；对诊断严重纤维化或肝硬化（F4），AUC 分别为 0.917、0.922、0.943、0.985 和 0.939（均 P<0.0001）。ADC、D 和 f 图的直方图指标在组间无显著差异（均 P>0.05）。
IVIM 衍生的 D*图直方图分析可用于 CLD 患者的肝脏纤维化分期，并提供超出平均值的更多定量信息。
