MR-DWI在结直肠癌术前N分期中的价值及与螺旋CT增强扫描的比较研究

王亚宁; 时高峰; 杜煜

doi:10.3969/j.issn.1000-8179.2011.05.010

摘要: 目的：结合术后病理结果比较螺旋CT与MRI对结直肠癌术前N分期的诊断价值。方法：选取河北医科大学第四医院2008年12月至2009年12月经手术病理证实的结直肠癌患者共53例。采用GE Light Speed Pro 32螺旋CT行平扫及增强扫描。使用Simens Avanto 1.5 T 超导型磁共振仪，均采用相控阵线圈行平扫及增强扫描。本实验数据采用SPSS 11.5软件进行统计分析。CT和MRI对结直肠癌术前N分期与术后病理对照采用χ2检验，并计算每种诊断方法的敏感度、特异度、阳性预测值、阴性预测值、符合率等数据。结果：CT、MRI扫描和磁共振弥散加权成像（MR-DWI）扫描3种方法检查淋巴结分期结果与组织病理学结果的符合率分别为56.6%、 58.5%、 73.6%。MR-DWI扫描的敏感度及阴性预测值最高，分别为92.3%和88.2%， CT为75.0%和66.7%， MRI扫描为42.6%和57.1%。MR-DWI扫描的特异度为55.6%，介于常规MRI （74.1%）扫描和CT （41.3%）之间。MR-DWI扫描的阳性预测值为66.7%，略高于CT （51.4%）和MRI （61.1%）扫描。经χ2分析， MR-DWI扫描诊断结果与组织病理结果具有中等相关性， Kappa值为13.927 （P=0.001）； CT和常规MRI扫描的诊断结果与组织病理结果无显著相关性， Kappa值分别为1.128 （P=0.288）和1.585 （P=0.208）。结论：通过对比CT、常规MRI和MR-DWI在结直肠癌淋巴结分期的诊断表现，显示出MR-DWI诊断结果与病理学结果具有较好的相关性，提示MR-DWI能够更准确地预测结直肠癌区域淋巴结转移情况。

Abstract: Evaluation of MR-DWI in Preoperative N-staging of Colorectal Carcinoma and Its Comparisonwith Contrast Helical CTYa'ningWANG, Gaofeng SHI, Yu DUCorrespondence to: Gaofeng SHI, E-mail: duyu2528@sina.comDepartment of Radiology, The Fourth Hospital of Hebei Medical University, Shijiazhuang 050011, Hebei, ChinaThis work was supported by and National Science and Technology Support Program (No. 2007BAIO5B05) and Key Provincial Medi-cal Research Project of Health Department of Hebei Province (No.20090511)Abstract Objective: To compare the value of CT and MRI in preoperative N-staging of colorectal carcinoma ( CRC ) and tocompare the imaging findings with the pathological findings. Methods: The study involved 53 histopathologically confirmed CRC pa-tients. Plain and contrast scanning were performed by a GE Light Speed Pro 32 spiral CT scanner. All MRI examinations were per-formed by a 1.5 Tesla Siemens Avanto Superconduction MRI unit. Different techniques were proposed for phased-array surface coilMRI in both plain and contrast examinations. All analyses were conducted with SPSS ll.5. Chi-square ( χ2) trend test was used to testthe relationship between the results of MRI and CT. Results: The coincidence rates of CT and MRI and MR-DWI findings with the re-sults of N staging and histopathology were 56.6 %, 58.5 % and 73.6%, respectively. The sensitivity and negative predictive valueranked the highest in the MR-DWI scan: 92.3 % and 88.2%. The values were 75 % and 66.7 % in CT, and 42.6 % and 57.1% in MRI,respectively. χ2test showed that there was a moderate correlation between the results of MR-DWI scanning and histopathology results.The kappa value was 13.927 ( P = 0.001 ). No statistical correlation was found between the diagnostic results of CT and conventionalMRI scan (without DWI) and pathologic examination. The Kappa values were 1.128 (P = 0.288 ) and 1.585 ( P = 0.208 ), respectively.Conclusion: MR-DWI is more accurate than CT and conventional MRI in diagnosis of CRC. MR-DWI can accurately predict the pres-ence of nodal metastasis in CRC patients.Keywords Colorectal carcinoma; N staging of neoplasms; Magnetic resonance; Computed tomography