扩散加权成像eADC值诊断前列腺良恶性结节价值探讨

目的探讨MRI扩散加权成像(DWI)的指数化表观扩散系数(e ADC)评价前列腺良恶性结节的可行性。方法选择2013年1月至2017年12月在南京医科大学附属南京医院行MRI DWI检查的可疑前列腺癌患者66例,年龄41~88岁,平均年龄60.00岁。行MRI检测,并与病理检测结果对照。MRI扫描序列包括T_1加权成像(T_1WI)、T_2加权成像(T_2WI)、脂肪抑制序列和DWI序列(b=0 s/mm^2、1 000 s/mm^2);并测量表观扩散系数(ADC)值、e ADC值。前列腺良恶性结节之间的ADC或e ADC值差异比较采用独立样本t检验。绘制所测数值的受试者工作特征曲线(ROC),比较曲线下面积,根据约登指数(灵敏度+特异度-1)最大值,计算ADC和e ADC值的诊断阈值,比较两者的灵敏度和特异度。结果共发现96个病灶,其中良性病灶(前列腺增生组)44个,恶性病灶(前列腺癌组)52个。前列腺增生组ADC值为(0.98±0.15)×10^(-3)mm^2/s,前列腺癌组ADC值为(0.63±0.15)×10^(-3 )mm^2/s;两组间差异有显著统计学意义(t=-11.62,P<0.01);以0.78×10^(-3)mm^2/s为最佳阈值,ADC诊断前列腺癌的灵敏度和特异度分别为93.20%、88.50%。前列腺增生组平均e ADC值为(0.20±0.17)×10^(-3 )mm^2/s,前列腺癌组e ADC值为(0.34±0.10)×10^(-3 )mm^2/s;两组间差异有显著统计学意义(t=5.30,P<0.01);以0.22×10^(-3 )mm^2/s为最佳阈值,e ADC诊断前列腺癌的灵敏度和特异度分别为94.20%、84.10%。ADC的ROC曲线下面积为0.953,e ADC的ROC曲线下面积为0.924,两者的诊断效能相近,差异无统计学意义。结论e ADC图消除了T_2投射效应,改进了组织对比度,是评估前列腺癌的一个有价值的参考指标。

Multi-slice CT contrast-enhanced presentations of advanced gastric cancer： associations with histo-differentiation and expression of p53 and P-glycoprotein

Background This study aimed to investigate multi-slice CT contrast-enhanced presentation of gastric cancer and its correlation with histo-differentiation and p53 and P-glycoprotein （P-gp） expression. Methods Sixty-six patients with gastric cancer in the present study underwent a multi-slice CT preoperative routine and dual-phase contrast-enhanced examination of the upper abdomen; postoperative specimens were used to determine histo-differentiation and the expression of p53 and P-gp. The correlation of multi-slice CT contrast-enhanced presentation with histo-differentiation and expression of p53 and P-gp was analyzed. Results The dual-phase contrast-enhanced ratio （CER） was not correlated with the histo-differentiation of gastric cancer （P 〉0.05）. Positive expression of p53 and P-gp was significantly higher in the cases of layered or heterogeneous enhancement than in the cases of homogenous enhancement （P 〈0.05）. Positive expression of p53 was also correlated with the arterial phase CER, tumor size and lymph node metastasis （P 〈0.05）, but not with infiltration thickness of the gastric wall, nor was it correlated with the portal phase CER （P 〉0.05）. Positive expression of P-gp was only correlated with the portal phase CER （P=0.005）. Conclusions Differently enhanced pattern and CER of the arterial and portal phase in gastric cancer correlate with its different histo-differentiation and expression of p53 and P-gp respectively. In addition, tumor size and lymph node metastasis of gastric cancer relate to the expression of p53.