直肠腔内超声与磁共振诊断直肠肿瘤的比较研究

目的 比较直肠腔内超声（endorectal ultrasound，ERUS）和磁共振成像（magnetic resonance imaging，MRI）在直肠肿瘤良恶性鉴别以及直肠癌术前分期中的诊断价值。方法 回顾性分析2015年5月至2019年6月于首都医科大学宣武医院诊治并经病理证实的76例直肠肿瘤患者，于术前7~10 d均行ERUS和MRI检查。病理结果显示，其中良性肿瘤患者33例，恶性肿瘤患者43例。以病理诊断为金标准，对比ERUS和MRI在直肠肿瘤良恶性鉴别以及直肠癌浸润深度（T分期）和区域淋巴结转移（N分期）判断的诊断价值。结果 76例患者中因4例患者肠腔狭窄或无法探测ERUS只对72例直肠肿瘤进行了ERUS检查分析。76例直肠肿瘤患者均进行MRI检查分析。ERUS诊断直肠癌的灵敏度、特异度、准确度分别为90.6%、90.9%、90.8%。MRI诊断直肠癌的灵敏度、特异度、准确度分别为83.7%、87.9%、90.2%。二者对比差异均无统计学意义。应用MRI对43例病理证实直肠癌患者进行TN分期判断分析，因4例患者肠腔狭窄或无法探测ERUS只对39例直肠癌进行TN分期判断分析。ERUS判断T1、T2、T3分期的准确度略高于MRI （分别为92.3% vs 88.3%，82.1% vs 74.4%，87.2% vs 86.0%），ERUS判断T4分期的准确度低于MRI （97.4% vs 100%）。ERUS判断T分期的总准确度高于MRI （79.5% vs 74.4%），但差异无统计学意义。ERUS判断N分期的准确度低于MRI （61.5% vs 74.5%），但差异无统计学意义。结论 对不同的T分期与N分期MRI与ERUS各具优势，MRI和ERUS在直肠肿瘤的良恶性鉴别诊断上均具有较高的准确度，二者对比差异无统计学意义。对于T1、T2、T3分期的直肠癌患者，优先考虑行ERUS检查。对于T4分期的直肠癌患者和直肠周围淋巴结转移的评估首选MRI检查。

Comparative study of endorectal ultrasound and magnetic resonance imaging used for diagnosing rectal neoplasms

Objective To compare the diagnosis values of endorectal ultrasound (ERUS) and magnetic resonance imaging(MRI) in differentiating benign from malignant tumors of rectal and in preoperative staging of rectal cancer. Methods A retrospective analysis was conducted on 76 patients with rectal tumor diagnosed and confirmed by pathology in Xuanwu Hospital from May 2015 to June 2019. All patients underwent ERUS and MRI examinations from 7 to 10 days before surgery. Pathological results indicated 33 patients with benign tumor and 43 patients with malignant tumor. The gold standard of pathological diagnosis was used to compare the diagnostic value of ERUS and MRI in the differentiating of benign and malignant rectal tumors and the depth of rectal cancer invasion (T staging) and regional lymph node metastasis (N staging). Results Out of a total of 76 patients, 72 rectal tumors were analyzed with ERUS, because of 4 cases of enteric stenosis or undetectable. MRI was performed on 76 patients with rectal tumor. The sensitivity, specificity and accuracy of ERUS in rectal cancer diagnosis were 90.6%, 90.9% and 90.8%, respectively, while those of MRI in rectal cancer diagnosis were 83.7%, 87.9% and 90.2% respectively. There was no statistical difference between the two methods. TN staging analysis was performed on 43 patients with MRI, while 39 patients with ERUS, due to 4 patients with enteric stenosis or undetectable. The results showed that the accuracy of ERUS in judging stages of T1, T2 and T3 was slightly higher than MRI (92.3% vs 88.3%,82.1% vs 74.4%, and 87.2% vs 86.0%, respectively). The accuracy of ERUS in judging T4 staging was lower than MRI (97.4% vs 100%). The total accuracy of T staging with ERUS was higher than that with MRI (79.5% vs 74.4%), without statistically significant difference. The accuracy of N staging with ERUS was lower than that with MRI (61.5% vs 74.5%), with statistically significant difference. Conclusion MRI and ERUS show respectively advantages in T and N stages. Both MRI and ERUS have high accuracy in the differential diagnosis of benign and malignant rectal tumors, without statistically significant difference. For patients with T1, T2 and T3 stages of rectal cancer, the first choice is row ERUS, while MRI is the first choice for the evaluation of patients with T4 stage rectal cancer and lymph node metastasis around the rectum.