DWI及DCE-MRI对直肠癌区域良恶性淋巴结的诊断价值

The diagnostic value of DWI and DCE-MRI for benign and malignant regional lymph nodes of rectal cancer

目的探讨常规MRI结合磁共振功能成像技术扩散加权成像(DWI)及动态对比增强磁共振成像(DCE-MRI)在鉴别直肠癌区域良恶性淋巴结的应用价值。方法回顾性分析65例经手术病理证实的直肠癌患者术前MRI资料。分析常规MRI及常规MRI+DWI+DCE检查对良恶性淋巴结的判断准确率与术后病理的一致性。良恶性淋巴结生成时间-信号强度曲线(TIC)类型、表观扩散系数(A DC)值及容量转移常数(K^trans)、容积分数(Ve)、回流速率常数(Kep)值的相关性。结果常规MRI检查对良恶性淋巴结判断的总准确率为67.7%( 317/468)。常规MRI+DWI+DCE对良恶性淋巴结判断的总准确率为78.2%(366/468)。良性淋巴结以Ⅰ型曲线为主,恶性淋巴结以Ⅲ型曲线为主。恶性淋巴结较良性淋巴结K^trans、Ve、Kep值升高,ADC值降低(P<0 .05)。结论常规MRI结合DWI及DCE-MRI有助于提高直肠癌区域恶性淋巴结的检出率,TIC类型、ADC值及K^trans、Ve、Kep值对鉴别直肠癌区域良恶性淋巴结有一定的应用价值。

Objective To study the application value of conventional MRI combined with DWI and DCE-MRI in differentiating benign and malignant regional lymph nodes of rectal cancer. Methods Preoperative MRI data of 65 patients with rectal cancer confirmed by operation and pathology were retrospectively analyzed. The accuracy of conventional MRI and conventional MRI plus DWI and DCE-MRI examination were analyzed in the diagnosis of benign and malignant lymph nodes,which was consistent with the postoperative pathology. The correlation of time-intensity curve (TIC) types,apparent diffusion coefficient (ADC) values and K^trans,Ve,Kep values with benign and malignant lymph nodes were also analyzed. Results The total diagnostic accuracy rate of conventional MRI for benign and malignant lymph nodes was 67.7%(317/ 468). The total diagnostic accuracy rate of conventional MRI plus DWI and DCE-MRI for benign and malignant lymph nodes was 78.2%(366/468). The benign lymph nodes were dominated by type I curve. The malignant lymph nodes were dominated by type Ⅲ curve. K^trans,Ve and Kep values were higher in metastatic lymph nodes than those of benign lymph nodes, and ADC values were lower than benign lymph nodes (P<0 .05). Conclusion Conventional MRI combined with DWI and DCE-MRI can improve the detection rate of regional malignant lymph nodes in rectal cancer. TIC types, ADC values and K^trans,Ve and Kepvalues have certain application value in differentiating benign and malignant regional lymph nodes of rectal cancer.