肝囊肿的弥散加权成像研究

目的 分析不同b值肝囊肿弥散加权像(DWI)的信号特点,并测量ADC值,为DWI对其他肝脏疾病的研究提供方向.方法 50例肝囊肿112个病灶进行磁共振DWI,分析b值为300、500、1000 s/mm2肝囊肿的DWI信号表现,并测量ADC值,分析b值为300、500 s/mm2时ADC值的分布情况.结果 肝囊肿在3种b值(300、500、1000 s/mm2)的DWI表现为低信号分别占79.5%、83.0%、92.0%,等信号分别占13.4%、11.6%、7.1%,高信号分别占7.1%、5.4%、0.9%;平均ADC值分别为(4.10±0.11)×10-3、(4.09±0.14)×10-3、(3.85±0.12)×10-3 mm2/s;b值＝300、500 s/mm2时;ADC值＝4.10×10-3 mm2/s分别为91例(占81.3%)、61例(占54.5%).结论 肝囊肿在DWI主要表现为低信号,且ADC值较稳定,选b=300、500 s/mm2时,ADC值接近一固定值4.10×10-3 mm2/s,结合DWI及ADC值可确诊肝囊肿.

Study of hepatic cysts with diffusion-weighted MR imaging

Objective To analyze the signal characteristics of hepatic cysts using different b values of diffusion-weighted imaging (DWI), and measure ADC values. To provide direction for studies of DWI in other liver diseases. Methods DWIs were obtained in 50 cases with 112 lesions. To evaluate DWI signal performance with b value of 300, 500, 1000 s/mm², and measure ADC values. Observing the distribution of ADC values with the b value of 300 s/mm²,500 s/mm².Results In three kinds of b value (300, 500, 1000 s/mm²) of DWI, low signal accounted respectively for 79.5%, 83.0%, 92.0%, high signal for 7.1%, 5.4%, 0.9%, and other signal for 13.4%, 11.6%, 7.1%. The mean ADC value was respectively (4.10±0.11)×10^-3, (4.09±0.14)×10^-3, (3.85±0.12)×10^-3 mm²/s. When b value was 300, 500 s/mm², the lesions with ADC=4.10×10^-3 mm²/s were respectively 91 cases (81.3%) and 61 cases(54.5%). Conclusion Hepatic cyst mainly shows low signal in DWI, and its ADC values more stable. ADC values close to a fixed value of 4.10×10^-3 mm²/s when b=300, 500 s/mm². Hepatic cyst can be diagnosed definite combining DWI with ADC value.