弥散加权成像和表观扩散系数在肝脏局灶性病变鉴别诊断中的研究

目的探讨分析弥散加权成像(diffusion-weighted imaging，DWI)和表观扩散系数(apparent diffusion coefficient，ADC)在肝脏局灶性病变鉴别诊断中的应用价值。 方法对2016年8月至2017年5月庆云县人民医院65例有肝脏内局灶性病变(focal liver lesion，FLL)的患者的DWI扫描(b＝50，400，800s/ mm²)进行回顾性分析。测量其中104个病灶(包括56个良性病变和48个恶性病变)实质部分的平均ADC值，避开内部坏死区。分别计算良性病变和恶性病变的特异度和敏感度。运用方差分析检测各类局灶性病变的组间差异。 结果恶性病变的平均ADC值为0.980×10^－3mm²/s，明显低于良性病变的平均ADC值(1.433×10^－3mm²/s)，有统计学意义(P<0.05)。当ADC值为1.066×10^－3mm²/s时，恶性肿瘤的特性度和敏感度分别为86.6%和73.6%。在所有的病灶中，约39.5%的病灶平均ADC值低于1.0×10^－3mm²/s，这些病灶中恶性病变占90%。约20%的病灶平均ADC值大于1.5×10^－3mm²/s，他们中有9.5%的为恶性病变。 结论DWI的应用提高了磁共振对于肝脏良恶性病变鉴别的能力，尽管ADC值不能作为肝局灶性病变良恶性鉴别的特异性指标，但其可以作为一项鉴别良恶性性病变的重要参考数据。

Clinical application of diffusion-weighted imaging and apparent diffusion coefficient in differential diagnosis of focal liver lesion

ObjectiveTo assess the application value of diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) in differential diagnosis of focal liver lesion (FLL). MethodsThe DWI data (b=50 400 800 s/mm²) of 65 patients with FLL from August 2016 to May 2017 in County People's Hospital were retrospectively analyzed.The mean ADC value was measured in 104 lesions (56 benign and 48 malignant) excluding internal necrotic areas.The sensitivity and specificity in distinguishing benign from malignant lesions were calculated.Analysis of variance was performed to detect differences among subgroups of solid lesions. ResultsThe mean ADC value of malignant lesions was 0.980×10^-3mm²/s, significantly lower than that of benign lesions (1.433×10^-3mm²/s, P<0.05). Applying an ADC cutoff of 1.066×10^-3mm²/s, the specificity and sensitivity for malignancy were respectively 86.6% and 73.6%.Of all lesions, 39.5% presented ADC values lower than 1.0×10^-3mm²/s, with 90.0% chance of malignancy.Above 1.5×10^-3mm²/s (about 20% of all lesions) chance of malignancy was 9.5%. ConclusionThe application of DWI can improve the ability in differentiating malignant from benign lesions.The ADC value can not be considered as a specific indicator for differential diagnosis of benign and malignant FLL, but it can be used as reference data.