Vliegen Roy F A, Beets Geerard L, von Meyenfeldt Maarten F, Kessels Alfons G H, Lemaire Etienne E M T, van Engelshoven Jos M A, Beets-Tan Regina G H
Department of Radiology, University Hospital of Maastricht, P. Debyelaan 25, 6202 AZ Maastricht, The Netherlands.
Radiology. 2005 Jan;234(1):179-88. doi: 10.1148/radiol.2341031403. Epub 2004 Nov 18.
To determine retrospectively whether addition of gadolinium-enhanced T1-weighted magnetic resonance (MR) sequence to T2-weighted turbo spin-echo (SE) MR imaging is valuable for preoperative assessment of T stage and circumferential resection margin in patients with primary rectal cancer.
Local institutional review board approved study and waived informed patient consent. Eighty-three patients with operable primary rectal cancer underwent preoperative MR imaging. Retrospectively, two observers independently scored T2-weighted turbo SE MR images and, in a second reading, T2-weighted images combined with gadolinium-enhanced T1-weighted turbo SE MR images for tumor penetration through rectal wall and tumor extension into mesorectal fascia. A confidence level scoring system was used, and receiver operating characteristic (ROC) curves were generated. Histologic findings were standard of reference. Difference in performance of T2-weighted and combined T2-weighted plus gadolinium-enhanced T1-weighted sequences was analyzed by comparing corresponding areas under ROC curves (A(z)) for each observer. Interobserver agreement was calculated by using linear weighted kappa statistics.
Addition of contrast-enhanced T1-weighted to T2-weighted MR imaging did not significantly improve diagnostic accuracy for prediction of tumor penetration through rectal wall (A(z) of T2-weighted vs T2-weighted plus T1-weighted images for observer 1, 0.740 vs 0.764; observer 2, 0.856 vs 0.768) and tumor extension into mesorectal fascia (A(z) for observer 1, 0.962 vs 0.902; observer 2, 0.902 vs 0.911). Diagnostic performance (A(z)) of MR and interobserver agreement were high for prediction of tumor extension into mesorectal fascia (kappa = 0.61, 0.74) but only moderate for penetration through rectal wall (kappa = 0.47, 0.45).
Gadolinium-enhanced MR sequences did not improve diagnostic accuracy for assessment of tumor penetration through rectal wall and tumor extension into mesorectal fascia.
回顾性确定在原发性直肠癌患者中，将钆增强T1加权磁共振（MR）序列添加到T2加权快速自旋回波（SE）MR成像中，对于术前评估T分期和环周切缘是否有价值。
本研究经当地机构审查委员会批准，并免除了患者的知情同意。83例可手术切除的原发性直肠癌患者接受了术前MR成像检查。回顾性地，两名观察者独立对T2加权快速SE MR图像进行评分，并在第二次读片中，对T2加权图像与钆增强T1加权快速SE MR图像进行评分，以评估肿瘤穿透直肠壁和肿瘤延伸至直肠系膜筋膜的情况。采用置信度评分系统，并生成受试者操作特征（ROC）曲线。组织学结果作为参考标准。通过比较每位观察者相应的ROC曲线下面积（A(z)），分析T2加权序列与T2加权加钆增强T1加权序列联合使用时的性能差异。观察者间的一致性采用线性加权kappa统计量进行计算。
在T2加权MR成像中添加对比增强T1加权序列，对于预测肿瘤穿透直肠壁（观察者1的T2加权图像与T2加权加T1加权图像的A(z)分别为0.740和0.764；观察者2的分别为0.856和0.768）以及肿瘤延伸至直肠系膜筋膜（观察者1的A(z)分别为0.962和0.902；观察者2的分别为0.902和0.911）的诊断准确性没有显著提高。MR对肿瘤延伸至直肠系膜筋膜的诊断性能（A(z)）和观察者间的一致性较高（kappa分别为0.61、0.74），但对穿透直肠壁的诊断性能仅为中等（kappa分别为0.47、0.45）。
钆增强MR序列在评估肿瘤穿透直肠壁和肿瘤延伸至直肠系膜筋膜方面，并没有提高诊断准确性。
