磁共振成像术在进展期胃癌术前诊断和分期中的应用研究

Magneitc resonance imaging used in preoperative diagnosis and staging of advanced gastric carcinoma

目的评价磁共振成像技术(MRI)在进展期胃癌术前分期和诊断中的价值。方法对11名正常受检者和34例术前经上消化道造影和内镜检查拟诊胃癌的患者行多方位、多序列MRI增强前后扫描。根据MR的图像对胃癌进行分期诊断和可切除性评估,并与手术病理结果对照。结果11名正常胃壁显示2层者有4名,在T1WI/SE上为等信号影伴外缘的低信号带;T2WI/TSE上为较低信号影伴外缘的低信号带。胃癌在T1WI呈等或低信号,T2WI呈稍高信号,增强后呈显著不均匀强化。MRI对T1、T2、T3和T4期胃癌的灵敏度为40.0%、89.5%、83.3%和100%;特异度为100%、76.9%、92.3%和96.7%;准确率为90.6%、84.4%、90.6%和96.9%。淋巴结转移总的灵敏度、特异度和准确率分别为66.7%、72.7%和68.8%。对周围器官侵犯的灵敏度、特异度和准确率分别为85.7%、100%和97.1%。32例术前分期准确率为84.4%(27/32),术前切除可能性估计的准确率93.8%(30/32)。结论MRI检查对于胃癌的诊断、分期以及术前评估有很大的价值。

Objective To evaluate the role of magnetic resonance imaging(MRI)in the preoperative diagnosis and staging of advanced gastric carcinoma.Method MRI was performed in11mormal subjects and34cases of gastric carcimona multidirectionally and multisequentially,with SE(spin echo)T 1 WI before and after contrast enhanced;SE high-weighed T 2 WI and SPIR images were obtained.These MR evaluations including MR-determined staging correlated with the surgicopathologic findings.Results Two layers of the gastric wall were visible in4normal cases.The gastric carcinoma showed middle-signal-intensity and irregular thickened wall in SE T 1 WI;higher signal-intensity in SE high-wieghed T 2 WI.The degree of extraserosal invasion may be classified by the appearance of low-signal-intensity band.The sensitivity in evaluating T 1 ,T 2 ,T 3 and T 4 classes was40.0%,89.5%,83.3%and100%,respectively.The specificity in evaluating T 1 ,T 2 ,T 3 and T 4 classes was100%,76.9%,92.3%and96.7%.The accuracy in evaluating T 1 ,T 2 ,T 3 and T 4 classes was90.6%,84.4%,90.6%and96.9%,respectively.MRI determined the overall N staging with66.7%sensitivity,72.7%specificity,68.8%accuracy.It had a very high accuracy for detecting the peripheral invasion.The sensitivity,specificity and accuracy of M staging was85.7%,100%and97.1%,respectively.The overall accuracy of MRI in determining TNM-staging and resectability was84.4%and93.8%respectively.Conclusion MRI is very helpful in the diagnosis and staging of gastric carcinoma.