| 郭秋,任克,徐克,孙文阁,吕卓,李兆峰.肝纤维化ADC值减低机制及与选取b值关系的实验研究[J].中国医学影像技术,2011,27(9):1756~1760 |
| 肝纤维化ADC值减低机制及与选取b值关系的实验研究 |
| Relationship between the mechanisms of hepatic fibrosis leading to ADC value decrease and selected b values: An experimental study |
| 投稿时间：2011-03-02 修订日期：2011-05-09 |
| DOI： |
| 中文关键词: 肝纤维化 扩散磁共振成像 表观扩散系数 |
| 英文关键词:Hepatic fibrosis Diffusion magnetic resonance imaging Apparent diffusion coefficient |
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| 中文摘要: |
| 目的 探讨ADC值随肝纤维化程度增加而减低的机制及b值取值在肝纤维化诊断中的价值。 方法 建立不同时期的家兔肝纤维化模型30只,对其行DWI。对每只动物在第1次扫描后结扎肝脏左外叶动脉及门静脉肝左外叶支,再次行相同序列MR扫描。分别在肝左外叶和肝右前叶及结扎血管后的肝左外叶选取ROI,测量ADC值。MR检查后取家兔肝脏行病理检查,并按病理结果分期、分组。 结果 随肝纤维化分期进展, ADC值逐渐降低,肝左外叶血管结扎后测量ADC值明显降低,但并未随肝纤维化程度的加重而明显变化。随着b值增大,图像质量下降,且ADC值亦逐渐减低。b=300、500、700、1000 s/mm2时,S0期、S1期与S2期、S3期、S4期之间比较,ADC值差异有统计学意义(P<0.05)。b=300 s/mm2时,S2期与S3、S4期比较,ADC值差异有统计学意义(P<0.05)。b=500 s/mm2时,S2期与S4期比较,ADC值差异有统计学意义(P<0.05)。 结论 不同程度肝纤维化导致ADC值减低的主要原因为肝内微循环障碍导致的血流灌注减少,较小b值对于判定肝纤维化严重程度更有价值。在有效范围内,b值越小,测量结果受血流灌注因素的影响越大,且判定肝纤维化程度越准确。 |
| 英文摘要: |
| Objective To investigate the mechanism of the reduction of ADC value with the increasing of hepatic fibrosis, and to observe the importance of b value in the diagnosis of the hepatic fibrosis. Methods Different stages of hepatic fibrosis models were established in 30 rabbits. Each model were scanned twice with the same sequences before and after the ligation of left lateral branches of hepatic artery and portal vein. ADC values of each model were measured on left lateral lobe, right anterior lobe and left lateral lobe before and after ligation. Pathological examinations of the livers were performed after MRI. According to pathological founding, the animals were divided into different stages of hepatic fibrosis. Results With the progress of hepatic fibrosis, ADC values decreased gradually. ADC values of left lateral lobe after ligation significantly reduced, but did not changed obviously with the corresponding of hepatic fibrosis. The increasing of b value brought image quality debasing, and the ADC values reduced gradually. When b=300, 500, 700, 1000 s/mm2, there were statistical differences among the ADC of S0, S1 and S2, S3, S4 (P<0.05). When b=300 s/mm2, there were statistical differences among the ADC of S2 and S3, S4 (P<0.05). When b=500 s/mm2, there were statistical difference between the ADC of S2 and S4 (P<0.05). Conclusion The main cause of vary degrees of hepatic fibrosis leading to reduction in ADC values is the disorder of intrahepatic microcirculation which inducing a decrease of blood flow. Small b values are valuable to observe the degrees of hepatic fibrosis. In a certain range, the smaller the b values, the greater the influence of perfusion factor, and the more correct to clarify the degree of hepatic fibrosis. |
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