Zhou Mei-Ling, Yan Fu-Hua, Xu Peng-Ju, Chen Cai-Zhong, Shen Ji-Zhang, Li Ren-Chen, Ji Yuan, Shi Jian-Ying
Department of Radiology, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
Zhonghua Yi Xue Za Zhi. 2009 Jul 7;89(25):1757-61.
To evaluate the clinical practical value of apparent diffusion coefficient (ADC) measurements based on diffusion-weighted MR imaging (DWI) for quantification of liver fibrosis and inflammation for hepatitis viral infection.
Diffusion-weighted MRI with parallel imaging was prospectively performed on 85 patients with chronic hepatitis and on 22 healthy volunteers within a single breath-hold using a single-shot spin-echo echo-planar sequence at b values of 100, 300, 500, 800 and 1000 s/mm2 respectively. ADC values of liver were measured with five different b values. The inflammation grades and fibrosis stages were evaluated histologically by biopsy. One-way analysis of variance and Spearman' s rank correlation test were used for statistical analysis. Receiver operating characteristics analysis was used to assess the performance of ADC in predicting the presence of stage > or = 2 and stage > or = 3 hepatic fibrosis, and grade > or = 1 hepatic inflammation.
There was moderate negative correlation between hepatic ADC values and fibrosis stage. And the best correlation was obtained for a b value of 800 s/mm2 (r = -0.697, P = 0. 000). At all b values there was a significant decrease in hepatic ADC in patients with stage < or = 1 versus stage > or = 2 fibrosis and stage < or = 2 versus stage > or = 3 fibrosis (P < 0.05). Hepatic ADC was a significant predictor of stage > or = 2 and > or = 3 fibrosis. The areas under the curve were 0.909 vs 0.917, sensitivity 76.6% vs 80.0% and specificity 88.3% vs 91.5% (ADC with a b value of 800 s/mm2, 1.26 x 10(-3) mm2/s or less and 1.19 x 10(-3) mm2/s or less). There was weak to moderate negative correlation between ADCs and inflammation grade. Hepatic ADC was a significant predictor of grade > 1 inflammation with an area under the curve of 0.781, sensitivity of 60.0% and specificity of 86.4% (ADC with a b value of 500 s/mm2, 1.54 x 10(-3) mm2/s or less).
The DWI measurement of hepatic ADC can be used to quantify liver fibrosis and inflammation. It will be a new approach for early diagnosis and therapeutic follow-up of hepatic fibrosis.
评估基于扩散加权磁共振成像（DWI）测量表观扩散系数（ADC）对病毒性肝炎感染所致肝纤维化和炎症进行定量分析的临床实用价值。
对85例慢性肝炎患者和22名健康志愿者采用单次激发自旋回波平面回波序列，在单次屏气状态下前瞻性地进行并行成像的扩散加权磁共振成像，b值分别为100、300、500、800和1000 s/mm2。用5种不同b值测量肝脏的ADC值。通过活检组织学评估炎症分级和纤维化分期。采用单因素方差分析和Spearman秩相关检验进行统计分析。采用受试者工作特征分析评估ADC预测≥2期和≥3期肝纤维化以及≥1级肝脏炎症的效能。
肝脏ADC值与纤维化分期呈中度负相关。b值为800 s/mm2时相关性最佳（r = -0.697，P = 0.000）。在所有b值下，纤维化分期≤1期与≥2期、≤2期与≥3期患者的肝脏ADC均显著降低（P < 0.05）。肝脏ADC是≥2期和≥3期纤维化的显著预测指标。曲线下面积分别为0.909对0.917，敏感度76.6%对80.0%，特异度88.3%对91.5%（b值为800 s/mm2时，ADC为1.26×10(-3) mm2/s及以下和1.19×10(-3) mm2/s及以下）。ADC与炎症分级呈弱至中度负相关。肝脏ADC是炎症分级>1级的显著预测指标，曲线下面积为0.781，敏感度为60.0%，特异度为86.4%（b值为500 s/mm2时，ADC为1.54×10(-3) mm2/s及以下）。
肝脏ADC的DWI测量可用于定量肝纤维化和炎症。这将是肝纤维化早期诊断和治疗随访的一种新方法。
