3.0 T MRI在直肠癌术前分期和评估中的应用价值

目的 探讨3.0 T MRI在直肠癌术前分期和评估中的应用价值。方法 收集经肠镜及病理确诊的103例 直肠癌患者资料，通过术前MRI影像判断T分期、是否出现肠旁淋巴结转移和筋膜受累，并测量肿瘤下缘-肛缘距离， 将MRI分期和评估结果与术后病理进行对照。结果 MRI诊断T1～2期5例，T3期72例，T4期26例，病理诊断T1期 5例，T2期16例，T3期60例，T4期22例，MRI T1～2、T3、T4期诊断敏感度和特异度分别为23.8%和100%、96.7%和 67.4%、90.9%和92.6%，两者一致性较好（Kappa=0.748，P＜0.01）。MRI诊断肠旁淋巴结转移74例，术后病理诊断肠 旁淋巴结转移66例，MRI诊断肠旁淋巴结转移敏感度、特异度分别为92.4%、64.9%（Kappa=0.601，P＜0.01）。接受肛 门切除术的18例患者中，MRI测量的肿瘤下缘-肛缘距离与术后大体标本差值≤6 mm，差异无统计学意义（P＞0.05）。 65例MRI判断筋膜受累阴性者均与术后病理诊断一致，38例MRI判断筋膜受累阳性者，其中12例为假阳性；MRI判 断筋膜受累敏感度、特异度分别为 100.0%、84.4%，MRI 和病理诊断的一致性较好（Kappa=0.732，P＜0.01）。结论 3.0 T MRI可准确地对直肠癌患者进行术前分期和评估，为临床诊疗提供帮助。

Application value of 3.0 T MRI in the preoperative staging and assessment of rectal cancer

Objective To explore the application value of 3.0 T MRI in the preoperative staging and assessment of rectal cancer. Methods Data of 103 patients with rectal cancer diagnosed by biopsy was collected. The T staging, situations of paracolic lymphatic metastasis and fascia involvement, and distance of tumor edge to anal verge were estimated by preoperative MRI. The stage and assessment of preoperative MRI and postoperative pathology were compared. Results MRI showed that there were 5 patients with stage T1-2, 72 patients with stage T3, and 26 patients with stage T4. And pathological diagnosis showed that there were 5 patients with stage T1, 16 patients with stage T2, 60 patients with stage T3, and 22 patients with stage T4. The sensitivity and specificity of stage T1-2, T3, and T4 were 23.8% and 100%, 96.7% and 67.4%, 90.9% and 92.6%, respectively. Results of MRI were broadly consonant with the results of pathology (Kappa=0.748, P＜0.01). MRI showed that there were 74 patients with paracolic lymphatic metastasis. Pathological diagnosis after surgery showed that there were 66 patients with paracolic lymphatic metastasis. The sensitivity and specificity for MRI diagnosis were 92.4% and 64.9%, respectively (Kappa=0.601, P＜0.01). Among the 18 patients received anal resection, the different value of distance of tumor edge to anal verge was less than or equal to 6 mm between MRI and postoperative specimen, with no significant difference (P＞0.05). Totally 65 patients without fascia involvement diagnosed by MRI were consonant with the results of postoperative pathology. Among the 38 patients with fascia involvement diagnosed by MRI, 12 patients were false-positive. The sensitivity and specificity were 100.0% and 84.4%, respectively (Kappa=0.732, P=0.000). Conclusion 3.0 T MRI can provide accurate preoperative staging and evaluation for patients with rectal cancer before the operation, and help in clinical diagnosis and treatment.