DWI、T_2WI及动态增强MRI对早期肝脓肿的诊断价值

Diagnosis value of DWI,T_2WI and dynamic enhanced MR imaging for early liver abscess

目的:早期肝脏脓肿的影像学诊断困难,本研究分析DWI、T2WI及Gd-DTPA增强序列在检测早期肝脓肿中的价值。方法:对17例患者的17个早期肝脏脓肿分别进行了DWI、T2WI及Gd-DTPA增强检查,统计脓肿坏死区、非坏死区及正常肝脏在各序列的信号强度,计算坏死区、非坏死区及周围正常肝脏的ADC值,对坏死区、非坏死区及周围正常肝脏的ADC值进行比较。结果:脓肿坏死腔的ADC值[(0.88±0.09)mm2/s]很低,低于正常肝脏[(1.31±0.12)mm2/s,P<0.05],同时明显低于无明显坏死区[(1.43±0.18)mm2/s,P<0.05],在DWI及T2WI上均呈高信号,T1WI呈低信号,且增强图像无强化;而无明显坏死区ADC值[(1.43±0.18)mm2/s]则高于正常肝脏[(1.31±0.12)mm2/s,P<0.05],DWI及T2WI均呈中等高信号,T1WI呈低信号,增强有明显强化。结论:早期肝脓肿的磁共振表现有一定特征性,磁共振弥散加权成像有助于早期肝脓肿的诊断。

Objective：The imaging diagnosis of early liver abscess is difficult. This study is to evaluate the diagnostic value of DWI,T2WI and dynamic enhanced MR imaging for early liver abscess. Methods： DWI,T2WI and dynamic enhanced imaging scans were performed in 17 patients with 17 early liver abscesses. The signal intensities and ADC values of necrotic area, nonnecrotic area and normal liver were measured and compared. Results： The ADC value of the necrotic areas of liver abscesses （[0.88±0.09] mm^2/s） was significantly lower than those of normal liver （[1.31±0.12] mm＆2/s,P〈0. 05） and non-necrotic area of liver abscesses （[1. 43±0.18] mm^2/s,P〈0. 05） ; there was also significant difference between the ADC values of the normal liver and non-neocrotic area （P〈0. 05）. The necrotic areas had a hyperintensity characteristic on DWI, T2WI and a hypointensity characteristic on T1WI; no enhancement was found on dynamic enhanced imaging. The non-necrotic areas had moderate hyperintensity on DWI, T2WI and hypointensity on T1WI; there was obvious enhancement on dynamic enhanced imaging. Conclusion： The early liver abscess is characterized on magnetic resonance imaging. The DWI scan is helpful for diagnosis of early liver abscess.