食管癌的MRI诊断

MRI diagnosis of esophageal carcinoma

目的：探讨食管癌的ＭＲＩ诊断。方法：回顾分析６４例经手术或活检病理证实的食管癌的食管ＭＲＩ。采用自旋回波序列，常规行矢状面扫描：视野 ２３ｃｍ×２３ｃｍ～３６ｃｍ×３６ｃｍ、层厚 ３． ５～４ｍｍ，横断面扫描：视野 ２０ｃｍ ×２０ｃｍ～２６ｃｍ × ２６ｃｍ、层厚 ６～１０ｍｍ，矩阵１９２×２５６， ３～４次采集。结果：正常节段食管在 Ｔ１ＷＩ上显示为低到等信号；在 Ｔ２ＷＩ上粘膜层和粘膜下层均呈高信号而肌层呈低到等信号，两种信号对比明显，矢状面上可以看到高信号的粘膜线，在横断面上粘膜线呈环形。对于发生肿瘤的节段，矢状面上Ｔ１ＷＩ可见食管不规则增粗形成肿块，Ｔ２ＷＩ肿瘤呈低到等或不均匀信号并可看到高信号的粘膜线中断。在横断面上食管壁非对称性增厚形成以管壁为轴心的软组织肿块，食管管腔不规则狭窄，Ｔ２ＷＩ上环形高信号的粘膜线中断。结论：ＭＲＩ有很高的软组织对比度，尤其是在 Ｔ２ＷＩ上可以清晰地区分食管壁的粘膜层和肌层，结合ＭＲＩ能够矢状面成像观察食管长轴全貌的优势。ＭＲＩ在食管癌的诊断中有很高的应用价值。

Objective: To study the application of MRI in the diagnosis of esophageal carcinoma. Methods: Sixty-four patients with esophageal carcinoma confirmed by biopsy and pathology were reviewed and analyzed. Spin-echo MR images were obtained with a field of view(FOV) of 23cm × 23cm ～ 36cm × 36cm, section thickness(ST) of 3. 5 ～ 4mm and matrix size(MTX) of 192 × 256 in sagit- tal view. And FOV of 20cm × 20cm ～ 26cm × 26cm, ST of 6～10mm, Mad of 192 × 256 in transaxial view. All images were obtained with 3～4 signal acquisition. Results: On T1WI MR images the entire esophageal wall showed low to intermediate signal intensi- ty. However, on T2WI the mucosa and submucosa of the esophageal wall showed high signal intensity while the muscularis propria showed low or intermediate signal intensity. The high signal line of the mucosa (and submticosa) of the esophageal wall was seen chear- ly. Compare with normal site in sagittal images, carcinoma appeared as an irregular mass of low or intermediate signal intensity on T1WI, and low to intermediate or inhomogeneous signal intensity on T2WI. In transaxial section, asymmetric increase in thickness of the esophageal wall resulted in lumpy mass of soft - tissue, the esophageal lumen showed irregular stenosis and the high signal line of the mucosa (and submucosa) of the esophageal wall appeared to be disrupted by the tumor mass. Condsston: MR images provide greater contrast of soft - tissue structure than those obtained with CT. Especially on T2WI, it can clearly divide the mucosa(submucosa) and the musoularis propria of the esophageal wall. Due to the advantage that MRI can show panorama of the esophagus in sagittal view, MRI is highly valuable in the diagnosis of esophageal carcinoma.