3.0T MRI和能谱CT对食管癌术前分期的比较

Comparison of 3.0T MRI and gemstone spectral computed tomography for preoperative T and N staging of oesophageal carcinoma

目的探讨3.0T MRI及能谱CT在食管癌术前T、N分期中的应用价值。方法对经病理证实的33例食管癌患者于术前行3.0T MR及能谱CT检查。MR行常规平扫(T2W、T2W脂肪抑制)、DWI及屏气快速三维扰相梯度回波(LAVA-Flex)平扫+三期增强扫描。CT行常规平扫及能谱模式动、静脉期增强扫描。2名高年资影像科医师双盲法对CT及MRI图像分别进行T、N分期,以术后病理为金标准,对照分析T、N分期的结果。结果 MRI和能谱CT诊断T分期的敏感度及特异度分别为68.42%(13/19)、85.71%(12/14)和78.95%(15/19)、42.86%(6/14)。MRI和能谱CT诊断N分期的敏感度及特异度分别为86.67%(13/15)、55.56%(10/18)和93.33%(14/15)、61.11%(11/18)。对于识别T3及T4期肿瘤,MRI的准确率(12/14,85.71%)明显高于CT(5/14,35.71%,P=0.02),而二者判断食管癌术前N分期的整体准确率差异无统计学意义[MRI:54.55%(18/33);CT:57.58%(19/33),P=1.00]。结论 3.0T MRI对食管管壁分层结构的显示优于能谱CT,而能谱CT判断N分期准确率有优势,二者结合有助更准确地判断食管癌术前T、N分期。

Objective To explore the value of gemstone spectral CT and 3.0T MRI in preoperative T,N staging of oesophageal carcinoma.Methods Thrity-three patients with histologically confirmed oesophageal carcinoma underwent CT and MRI before operation.MRI protocol involved acquisition of T2 W FSE,T2 W FS FSE,DWI,breath-hold liver acquisition with volume acceleration（LAVA-Flex）and enhanced LAVA-Flex sequences.Contrast enhanced CT scans performed in the arterial and venous phases using the gemstone spectral imaging（GSI）mode.Two experienced radiologists independently analyzed the MRI and CT findings,and the results were compared with the respective pathologic findings.Results For T staging,the sensitivity and specificity of MRI was 68.42%（13/19）and 85.71%（12/14）,respectively,while the CT values were 78.95%（15/19）and 42.86%（6/14）,respectively.For N staging,the sensitivity and specificity of MRI was86.67%（13/15）and 55.56%（10/18）,respectively,while the CT values were 93.33%（14/15）and 61.11%（11/18）,respectively.The accuracy of MRI（85.71% [12/14]）was superior to CT（35.71% [5/14]）for T3 and T4stage（P=0.02）.However,no statistically significant differences were detected between the accuracies of MRI and CT in N stage（MRI：54.55% [18/33];CT：57.58% [19/33],P=1.00）.Conclusion 3.0T MRI is superior to gemstone spectral CT in showing the structure of oesophageal wall.However,gemstone spectral CT is superior to 3.0T MRI in identifying mediastinal lymph nodes.Combination of the two modalities might optimize preoperative T,N staging of oesophageal carcinoma.