Meyenberger C, Huch Böni R A, Bertschinger P, Zala G F, Klotz H P, Krestin G P
Department of Internal Medicine, University Hospital, Zurich, Switzerland.
Endoscopy. 1995 Sep;27(7):469-79. doi: 10.1055/s-2007-1005751.
Endoscopic ultrasound has become the best available method for local staging of primary rectal cancer and diagnosing recurrent local disease. The aim of this study is to compare the value of endoscopic ultrasound (EUS) to magnetic resonance imaging with an endorectal coil (EMRI).
Twenty-one patients (11 women, 10 men, mean age 63 years, range 31-79) with primary rectal cancer (n = 6) or follow-up examinations for recurrent local disease (n = 15) were investigated by EUS using an echo colonoscope (CF-UM 20, Olympus Optical) and by endorectal coil MRI on a 1.5 tesla MR system (General Electric). T2-weighted and contrast-enhanced T1-weighted images were obtained. The results of preoperative examinations were compared to histopathological findings regarding the T staging, with special focus on the transmural tumor infiltration.
EUS identified all tumors, whereas one tumor was missed by EMRI. EUS was superior to EMRI in T staging (accuracy 83%/40%), due to the better differentiation between T1 and T2 tumors, as the endorectal coil could not differentiate between stage T1 and stage T2. The accuracy of EMRI in assessing perirectal infiltration was 80%, compared to EUS with 100%. Local tumor recurrence was found in six of 15 patients, without endoscopic signs of recurrent disease in four of them. All were detected by EUS. Only one recurrence was missed by EMRI. Accuracy and positive and negative predictive values in follow-up examinations for recurrent disease for EUS were 93%, 86%, and 100%, and for both the T2-weighted and T1-weighted contrast-enhanced sequences of endorectal coil MRI, they were 93%, 100%, and 90%, respectively.
Endoscopic ultrasound and endorectal coil MRI are comparable methods in the preoperative staging and early diagnosis of recurrent rectal cancer. The advantages of EUS are the small diameter of the instrument, availability, and lower costs. In contrast, EMRI is operator-independent, and may become important for combined local and distant staging and follow-up examination in rectal cancer, if contrast-enhanced imaging can improve the sensitivity for liver metastases.
超声内镜已成为原发性直肠癌局部分期及诊断局部复发性疾病的最佳可用方法。本研究旨在比较超声内镜（EUS）与直肠内线圈磁共振成像（EMRI）的价值。
对21例患者（11例女性，10例男性，平均年龄63岁，范围31 - 79岁）进行了研究，其中原发性直肠癌患者6例，因局部复发性疾病进行随访检查的患者15例。使用超声结肠镜（CF - UM 20，奥林巴斯光学）对患者进行EUS检查，并在1.5特斯拉磁共振系统（通用电气）上采用直肠内线圈MRI检查。获取了T2加权和对比增强T1加权图像。将术前检查结果与关于T分期的组织病理学结果进行比较，特别关注肿瘤的透壁浸润情况。
EUS识别出了所有肿瘤，而EMRI漏诊了1例肿瘤。在T分期方面，EUS优于EMRI（准确率83%/40%），这是因为EUS能更好地区分T1和T2肿瘤，而直肠内线圈无法区分T1期和T2期。EMRI评估直肠周围浸润的准确率为80%，而EUS为100%。15例患者中有6例发现局部肿瘤复发，其中4例无内镜下复发疾病迹象。所有复发均被EUS检测到。EMRI仅漏诊了1例复发。EUS在复发性疾病随访检查中的准确率、阳性预测值和阴性预测值分别为93%、86%和100%，直肠内线圈MRI的T2加权和T1加权对比增强序列的相应值分别为93%、100%和90%。
超声内镜和直肠内线圈MRI在直肠癌术前分期及早期复发诊断中是可比的方法。EUS的优点是器械直径小、可用性高且成本较低。相比之下，EMRI不依赖操作人员，如果对比增强成像能提高对肝转移的敏感性，那么它在直肠癌的局部和远处联合分期及随访检查中可能会变得很重要。
