【摘要】 目的评价不同b值磁共振扩散加权成像对胆囊癌的显示能力和最佳b值的选择;并探讨表观扩散系数值与胆囊癌分化程度的关系。方法对33例胆囊癌患者术前行常规MRI和DWI检查。测量肿瘤的ADC值,计算多b值扩散成像和T2WI图像中的信噪比、对比噪声比及信号强度比等数据;对经手术病理证实的33例胆囊癌患者进行病理分级,比较不同b值时不同分化程度胆囊腺癌的ADC值;并进行统计学分析。结果 33例胆囊癌病灶均被DWI检出,肿瘤的SNR和肿瘤与正常肝脏的CNR随b值的增加逐渐下降,而肿瘤的SIR随b值增加逐渐升高。b值800s/mm2时DWI图像肿瘤与正常肝脏的CNR、肿瘤的SIR和SNR均高于T2WI,差异有统计学意义(P<0.05)。胆囊腺癌的ADC值随着b值增高逐渐变小,差异有统计学意义(P<0.05)。结论胆囊癌扩散加权成像的最佳b值为800s/mm2,可以得到胆囊癌的良好显示;胆囊腺癌ADC值随着肿瘤分化程度的降低而减小。更多还原

【Abstract】 Objective To measure the sensitivity of diffusion-weighted imaging,determine the most appropriate b value for DWI and also,to explore the correlation between the apparent diffusion coefficient to and the degree of gallbladder cancer differentiation.Methods Preoperative diffusion-weighted imaging and magnetic resonance examinations were performed for 33patients with gallbladder cancer.Tumor ADC values were measured,and the signal-to-noise ratio,contrastto-noise ratio,and signal-intensity ratio between the diffusion-weighted images with various b values as well as the T2-weighted images were calculated.33patients pathologically confirmed were pathologically graded to compare the ADC value with different b values of tumor at different degrees of differentiation,and the results were statistically analyzed.Results All 33cases of gallbladder cancer were detected by DWI.As the b value increased,tumor signal-to-noise ratio and contrast-to-noise ratio between the tumor and normal liver gradually decreased,but the tumor signal-intensity ratio gradually increased.When b=800s/mm2,contrast-to-noise ratio between tumor and normal liver,tumor signal-intensity ratio, and tumor signal-noise ratio of diffusion-weighted images were all higher than those of T2-weighted images;the differences were statistically significant(P <0.05).As the b value increased,the tumor ADC value gradually declined.As the degree of differentiation decreased,the tumor ADC value declined.Conclusion The b value of 800s/mm2was the best in DWI of gallbladder cancer;the lesion ADC value declined as the degree of cancerous tissue differentiation decreased.更多还原