扩散加权成像联合动态增强MRI诊断前列腺癌的定量分析研究

Quantitative analysis of DWI combined with DCE-MRI in diagnosis of prostate cancer

目的:探讨MR扩散加权成像(diffusion weighted imaging,DWI)和动态增强MRI(dynamic contrast enhanced MRI,DCE-MRI)定量参数分析对前列腺癌的诊断价值。方法:回顾性分析23例前列腺癌(prostate carcinoma,PCa)及40例前列腺增生(benign prostate hyperplasia,BPH)患者常规MRI、DWI及DCE-MRI资料,获得表观扩散系数(apparent diffusion coefficient,ADC)以及血管渗透性定量参数容积转运常数(volume transfer constant,K^(trans))、速率常数(rate constant,K_(ep))、血管外细胞外间隙容积分数(extravascular extracellular space volume fraction,V_e)。以病理结果为金标准,比较4种参数在前列腺癌与前列腺增生之间的差异,应用受试者工作特征(receiver operating characteristic,ROC)曲线分析4种参数及ADC-K^(trans)联合诊断前列腺癌的灵敏度、特异度、约登指数。结果:ADC、K^(trans)、K_(ep)、V_e值在前列腺良恶性病变诊断中差异均有显著统计学意义(P<0.01),其中ADC、K^(trans)及ADC-K^(trans)的灵敏度、特异度及约登指数分别为87.5%、91.3%、78.8%,90.0%、87.0%、77.0%,90.0%、91.3%、81.3%。结论:定量参数ADC、K^(trans)、K_(ep)及V_e值对前列腺病变诊断具有一定的价值,ADC-K^(trans)联合的灵敏度、特异度及约登指数高于任何单一参数,具有更高的前列腺癌诊断价值。

Objective： To investigate the value of quantitative parameters of diffusion weighted imaging （DWI） and dynamic contrast enhanced MRI （DCE-MRI） in diagnosing prostate cancer. Methods： A total of 23 patients with prostate cancer （PCa） and 40 patients with benign prostate hyperplasia （BHP） confirmed by histopathology were collected. They all underwent conventional MRI, DWI and DCE-MRI examinations. Then the values of apparent diffusion coefficient （ADC）, volume transfer constant （Ktrans）, rate constant （Kep） and extravascular extracellular space volume fraction （Ve）, were measured and compared between PCa and BPH groups. The receiver operating characteristic （ROC） curve was used to analyze the diagnostic sensitivity, specificity and Youden index ofADC, K^trans, Kep, Ve and ADC-K^trans. Results： There were statistically significant differences in the diagnostic values of ADC, K^trans, Kep and Ve between PCa and BPH groups （P〈0.01）. ROC curves showed that the sensitivity, specificity and Youden index of ADC, K^trans and ADC-K^trans in the diagnosis of PCa were 87.5%, 91.3%, 78.8%; 90.0%, 87.0%, 77.0%; and 90.0%, 91.3%, 81.3%, respectively. Conclusion： The quantitative parameters of DWI and DCE-MRI including ADC, K^trans, Kep and Ve have important value in diagnosing prostate diseases. The sensitivity, specificity and Youden index of ADC-Ktrans are higher than each single parameter. DWI combined with K^trans could diagnose PCa better.