磁共振多序列成像在直肠癌T分期中的临床应用

Clinical application of MR imaging multiple sequences in preoperative T staging of rectal carcinoma

目的探讨高分辨率磁共振成像中各成像序列在直肠癌T分期的应用价值。方法对25例直肠癌患者术前1周内完成MR检查且术前均未进行放化疗。MRI检查中分别扫描T2WI序列、DWI及对比增强T1WI图像,分别对病灶显示清晰度、肠壁浸润深度及是否侵犯浆膜层的显示与术后病理结果进行对比分析,分别评价MRI中T2WI序列、对比增强T1WI序列对直肠癌T分期判断的准确性与敏感性。结果在磁共振各序列图像中直肠癌常表现为孤立的肿块或肠壁不均匀增厚。在T2WI序列上,瘤体呈等或低信号,DWI序列中呈高信号,增强扫描强化明显。本组病例MRI中T2WI序列对直肠癌患者T分期的准确性、敏感性、特异度分别为:84%(21/25)、96.2%(25/26)、50%(1/2);增强T1WI序列的准确性、敏感性、特异度分别为:88%(22/25)、96.2%(25/26)、66.7%(2/3)。结论 MRI能清楚地显示直肠癌的部位、范围,能较准确地在术前对T分期进行判断。

Objective To compare the diagnostic efficacy and clinical value of magnetic resonance imaging （MRI） multiple sequences for T staging rectal cancer. Methods Between January and December 2015, a total of 25 patients underwent preopera- tive MR imaging with phase-array coil at 3.0 T MR unit. There were 18 men and 7 women. The average age of patients was 64. 08. Turbo spin echo （FS-TSE） T2-weighted sequence, Diffusion weighted imaging （DWI） , and contrast enhanced T1 -weigh- ted sequence were utilized. The conspicuity of bowel wall, the sensitivity and specificity of MRI in detecting the infihrating depth to the bowel wall and the surrounding tissues, and the accuracy rate of diagnosis were calculated. Results The rectal carcinomas were equisignal or hypointense in T2-weighted sequence, all of high signal on DWI and enhancement was obvious in contrast en- hanced T1 -weighted sequence. The accuracy, sensitivity, and specificity of FSTSE in rectal cancer were 84% （21/25） , 96.2% （25/26）, 50% （1/2）, respectively. The accuracy, sensitivity, specificity of contrasted enhancement T1 -weighted sequence rec- tal cancer were 88% （22/25）, 96.2% （25/26）, 66.7% （2/3）. Conclusion MRI can depict the extension of the rectal cancer clearly, which can provide a fairly high accuracy rate in T staging.