IVIM扩散加权成像在肝硬化背景下小肝癌诊断中的应用价值

目的：探讨MRI对比增强联合体素内不相干运动扩散加权成像(IVIM-DWI)技术对肝硬化背景下小肝癌的诊断价值。方法选择2014年11月至2016年1月在本院收治的肝硬化合并小肝癌患者27例(共32个病灶)，均行常规MRI (包括T1WI、T2WI及LAVA多期增强扫描)和IVIM-DWI序列扫描，分析比较常规MRI、两者联合（常规MRI+IVIM-DWI序列扫描）对肝硬化背景下小肝癌的诊断价值；根据IVIM-DWI参数图测量小肝癌及瘤周肝硬化实质平均ADC值(Stand ADC值)、慢速表观扩散系数(D值)、快速表观扩散系数(D*值)和快速扩散成分所占比例(f值)并进行统计学分析。结果联合应用IVIM-DWI技术得出的检出率和诊断符合率分别为100%、96.88%，优于常规MRI的97%、87.50%，但两种方法比较差异均无统计学意义(P>0.05)；IVIM-DWI参数图上所测的小肝癌Stand ADC值(1.09±0.15)×10-3 mm2/s]、D值(0.91±0.11)×10-3 mm2/s]、D*值(31.29±8.14)×10-3 mm2/s]和f值(23.23±7.17)%]均低于瘤周肝硬化实质Stand ADC值：(1.27±0.14)×10-3 mm2/s、D值(1.05±0.16)×10-3 mm2/s、D*值(61.27±12.59)×10-3 mm2/s和f值(32.83±5.71)%]，两者比较差异均有统计学意义(P<0.05)。结论常规MRI联合应用IVIM-DWI技术有助于提高对肝硬化背景下小肝癌的诊断能力。

Value of intravoxel incoherent motion diffusion-weighted imaging in diagnosis of small hepatocellular carcinoma in liver cirrhosis

Objective To investigate the value of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) and magnetic resonance imaging (MRI) in detection and qualitative diagnosis of small hepatocellular carci-noma (SHCC) in liver cirrhosis. Methods From November 2014 to January 2016, 27 patients of liver cirrhosis com-bined with SHCC (32 lesions) who admitted to our hospital were selected, which all underwent conventional MRI (T1WI+T2WI+LAVA dynamic contrast enhancement) and IVIM-DWI. The value of conventional MRI and their combi-nation (conventional MRI+IVIM-DWI) in diagnosis of SHCC was comparatively analyzed. Based on IVIM-DWI para-metric diagrams, the apparent diffusion coefficient (Stand ADC value), slow apparent diffusion coefficient (D value), fast apparent diffusion coefficient (D*value) and fraction of fast ADC (f value) of the region of interest in the tumor sec-tion and the non-tumor section were acquired and compared. Results The detection rate and diagnostic coincidence rate of combination (conventional MRI+IVIM-DWI) for SHCC were 100%and 96.88%respectively, which were higher than those of conventional MRI (97%and 87.50%, respectively), but there was no significant difference between the two groups (P>0.05). The Stand ADC value, D value, D*value and f values in the tumor section were (1.09±0.15)×10-3 mm2/s, (0.91 ± 0.11) × 10-3 mm2/s, (31.29 ± 8.14) × 10-3 mm2/s, (23.23 ± 7.17)%, respectively, which were lower than those of the non-tumor section of (1.27±0.14)×10-3 mm2/s, (1.05±0.16)×10-3 mm2/s, (61.27±12.59)×10-3 mm2/s, (32.83±5.71)%, with statistically significant differences (P<0.05). Conclusion The combination of conventional MRI and IVIM-DWI can help to improve the diagnostic ability of small hepatocellular carcinoma in liver cirrhosis.