MR扩散加权成像对膀胱尿路上皮癌的诊断价值

The role of diffusion-weighted MR imaging in the diagnosis of bladder urothelial cancer

目的探索MR扩散加权成像(DWI)对膀胱尿路上皮癌的诊断价值。方法从2015年6月至2016年12月,将我院已进行MR扩散加权成像检查共72例膀胱疾病患者,根据病理结果分为膀胱良性疾病组(n=23)和膀胱尿路上皮癌组(n=49),比较膀胱良性疾病组和膀胱尿路上皮癌组术前的肿瘤平均表观扩散系数(ADC)值,采用受试运算特性(ROC)方法确定最佳诊断Cut-off值。结果膀胱良性疾病组和膀胱尿路上皮癌术前ADC值分别为(1.86±0.40)×10^(-3) mm^2/s和(0.93±0.11)×10^(-3) mm^2/s,差别具有统计学意义(P<0.01);ADC值在肿瘤分级间的差别有统计学意义;ADC值诊断膀胱尿路上皮癌的ROC曲线下面积为0.705;ADC值诊断膀胱尿路上皮癌时兼顾敏感性和特异性的最佳Cut-off值为1.32×10^(-3) mm^2/s,此Cut-off值的敏感性和特异性分别为87.2%和82.9%。结论 MR扩散加权成像ADC值可作为一种早期诊断膀胱尿路上皮癌的客观指标。

Objective To evaluate the value of diffusion-weighted MR imaging in diagnosis of urothelial cancer. Methods From June 2015 to December 2016, 72 consecutive patients with suspicious bladder lesions were accessed in our hospital. According to the results of pathological examination, the patients were divided into two groups： benign lesions group （n=23） and urothelial cancer group （n=49）. The apparent diffusion coefficient （ADC） values of all patients was analyzed. The receiver operating characteristic （ROC） curves were generated by plotting the sensitivity versus specificity. Area under the cures was calculated for ADC assay. Results There was significant difference in ADC values between benign lesions group and urothelial cancer group [（1.86±0.40）×10-3mm2/s vs （0.93±0.11） ×10-3mm2/s, P〈0.01]. Area under the ROC curves of ADC values were 0.705. The specificity and sensitivity of ADC values were 82.9% and 87.2% respectively at the optimum cutoff value （1.32×10-3 ） mm2/s. Conclusions ADC value could provide an objective and reliable biomarker for the early diagnosis of bladder urothelial cancer.