Brown G, Richards C J, Newcombe R G, Dallimore N S, Radcliffe A G, Carey D P, Bourne M W, Williams G T
Department of Clinical Radiology, University Hospital of Wales, Cardiff, Wales.
Radiology. 1999 Apr;211(1):215-22. doi: 10.1148/radiology.211.1.r99ap35215.
To evaluate the accuracy of thin-section magnetic resonance (MR) imaging (in-plane resolution, 0.6 x 0.6 mm) in the preoperative assessment of the depth of extramural tumor infiltration, which is a major prognostic indicator in rectal cancer.
In a prospective study of 28 consecutive patients, preoperative MR imaging was performed. The tumor stage according to the TNM classification system and the measured depth of extramural tumor invasion in matched MR images and histopathologic slices were compared.
Preoperative MR imaging correctly indicated the histopathologic tumor stage in all 25 patients in whom comparisons were possible. The difference between the depth of extramural tumor measured on preoperative MR images and corresponding measurements on histopathologic slices of the resection specimen ranged from -5.0 mm to +5.5 mm (mean difference, +0.13 mm; 95% CI: -2.72, +2.98 mm), indicating good agreement. The mesorectal fascia, and the relation of the tumor to it, could be visualized in every case. In all five patients with involvement of the circumferential excision margins of resection specimens, extensive extramural invasion was identified on preoperative MR images.
Preoperative thin-section MR imaging accurately indicates the tumor stage of rectal cancer and depth of extramural tumor infiltration. It provides valuable information for identifying T3 tumors for preoperative adjuvant therapy in patients who are at high risk of failure of complete excision.
评估薄层磁共振成像（平面分辨率为0.6×0.6mm）在术前评估壁外肿瘤浸润深度方面的准确性，壁外肿瘤浸润深度是直肠癌的主要预后指标。
对连续28例患者进行前瞻性研究，术前行磁共振成像检查。比较根据TNM分类系统确定的肿瘤分期以及在匹配的磁共振图像和组织病理学切片中测量的壁外肿瘤浸润深度。
在所有25例可进行比较的患者中，术前磁共振成像正确显示了组织病理学肿瘤分期。术前磁共振图像上测量的壁外肿瘤深度与切除标本组织病理学切片上相应测量值之间的差异为-5.0mm至+5.5mm（平均差异为+0.13mm；95%可信区间：-2.72，+2.98mm），表明一致性良好。在每例病例中均可观察到直肠系膜筋膜及其与肿瘤的关系。在切除标本环周切缘受累的所有5例患者中，术前磁共振图像上均发现广泛的壁外侵犯。
术前薄层磁共振成像能准确显示直肠癌的肿瘤分期和壁外肿瘤浸润深度。它为识别T3期肿瘤以对完全切除失败风险高的患者进行术前辅助治疗提供了有价值的信息。
