不同b值弥散加权成像在前列腺癌诊断中的应用

Application of different-b-value diffusion-weighted imaging in diagnosis of prostate cancer

目的探讨不同b值弥散加权成像在前列腺癌诊断中的应用价值。方法收集我院2014年1月至2016年9月经病理确诊的前列腺癌患者40例进行研究,分别进行b值=300 s/mm2,800 s/mm2,1 000 s/mm2DWI扫描,测量不同b值条件下前列腺癌区信号强度(SI)及表观弥散系数(ADC),并对结果进行统计分析。结果 40例前列腺癌患者在b=300 s/mm2时,25例患者DWI呈等低信号,7例稍高信号,8例高信号;b值=800 s/mm2时,11例呈稍高信号,29例高信号;b=1 000 s/mm2时均呈高信号。随着b值增加,前列腺癌区信号强度及ADC值逐渐降低,不同b值条件下,信号强度及ADC值比较差异均有统计学意义(P<0.05)。结论随着b值增加,DWI对前列腺癌越敏感,信号对比越明显,但图像信噪比降低,在b值=1 000 s/mm2时,有助于前列腺癌的诊断。

Objective To investigate the application of different-b-value diffusion-weighted imaging（DWI） in diagnosis of prostate cancer. Methods Forty patients with prostate cancer diagnosed by pathology in our hospital from January 2014 to September 2016 were enrolled in the study. GE Signa HDx 3.0T MRI scanner was used to scan DWI at b-value of 300 s/mm2, 800 s/mm2 and 1 000 s/mm2. The signal intensity（SI） and apparent diffusion coefficient（ADC）of prostate cancer were measured under different b values, and the results were statistically analyzed. Results When b-value was 300 s/mm2, 25 cases showed low signal intensity, with 7 cases of slightly high signal intensity, and 8 cases of high signal intensity. When b-value was 800 s/mm2, 11 cases showed slightly high signal intensity, and 29 cases showed high signal intensity. When b-value was 1 000 s/mm2, all the patients with prostate cancer showed high signal intensity.With b-value increased, the signal intensity and ADC of prostate cancer area decreased gradually. In different b values, signal intensity and ADC value showed statistically significant differences（P〈0.05）. Conclusion With the increase of b-value, DWI is more sensitive for prostate cancer and signal contrast is more clear, but the signal to noise ratio of the image reduceds. It is suggested that the sensitivity to prostate cancer is more predictable on b-value=1,000 s/mm2 DWI.