结肠癌与直肠癌DWIBS表现对比分析

Background Suppression Diffusion-Weighted Imaging Findings of Colonic Cancer and Rectal Cancer:A Comparison Study

目的探讨结肠癌与直肠癌磁共振背景抑制扩散加权成像(DWIBS)表现间的关系。方法对经肠镜证实的24例结肠癌及25例直肠癌患者,术前行磁共振DWIBS检查。对比分析结肠癌与直肠癌之间肿瘤表观扩散系数(ADC)值、肿瘤信号强度、肠壁病变厚度、肿瘤侵犯肠周径情况及淋巴结转移数目是否存在差异,并分别采用t和t'检验。结果 2例结肠癌DWIBS漏诊。经统计学分析,DWIBS图像上肿瘤ADC值、信号强度、肠壁病变厚度及肿瘤侵犯肠周径情况在结肠癌与直肠癌间存在差异(t=4.34,P<0.05;t'=2.07,P<0.05;t'=3.77,P<0.05;t'=3.92,P<0.05),淋巴结转移数目在两者间的差异无统计学意义(t'=-0.39,P>0.05)。结论结肠癌肿瘤ADC值大于直肠癌,DWIBS信号强度小于直肠癌,即结肠癌肿瘤组织扩散受限程度要低于直肠癌;结肠癌DWIBS图像上肠壁病变厚度及肿瘤侵犯肠周径情况要大于直肠癌。此外,DWIBS对结肠癌的筛查存在假阴性。

Objective To explore background suppression diffusion-weighted imaging （DWIBS） findings of the colonic cancer and rectal cancer, and to discuss the relationship between the two cancers. Methods A total of 24 patients with colon cancer and 25 patients with rectal cancer were enrolled in this study. The diagnosis was proved by colonoscopy in all patients. Before the operation DWIBS MR scanning was performed. The ADC value and the signal intensity of the tumor, the thickness of the diseased intestinal wall, the involvement of the intestinal circumference and the number of lymph node metastasis were determined, and the results were statistically analyzed using t test and t＇test and compared between the two cancer groups. Results DWIBS missed the diagnosis of colonic cancer in two patients. Statistical analysis showed that statistically significant differences in the ADC value and the signal intensity of the tumor, the thickness of the diseased intestinal wall and the involvement of the intestinal circumference existed between the colonic cancer group and the rectal cancer group （t =4. 34, P 〈0. 05; t＇ =2. 07, P 〈0. 05; t＇ =3.77, P 〈0. 05; t＇ =3.92, P 〈0.05）, while the differences in the number of lymph node metastasis between the two groups was not statistically significant （ t＇ = 0. 39, P 〉 0.05）. Conclusion The ADC value of the colonic cancer is greater than that of the rectal cancer, while the DWIBS signal intensity of the colonic cancer is lower than that of the rectal cancer, namely the constrained extent of diffusion in colonic cancer is lower than that in rectal cancer. On DWIBS images the thickness of the diseased intestinal wall and the involvement of the intestinal circumference in colonic cancer are greater than those in rectal cancer. Besides, for the screening of colonic cancer DWIBS may carry false-negative results.