50例椎管神经鞘瘤MRI分析

目的分析椎管内神经鞘瘤的MRI表现，提高其术前诊断准确率。方法回顾性分析经手术病理证实的50例椎管内神经鞘瘤的MRI表现。男25例，女25例，神经鞘瘤49例，恶性外周神经鞘膜瘤1例。全部病例均行MR平扫及增强。结果50例均位于脊髓外硬膜下，初次MRI诊断正确44例（88％），漏诊及误诊各3例（6％）。漏诊的3例均位于下腰段，1例为直径仅5mm的神经鞘瘤，2例瘤体完全囊变，菲薄的囊壁淹没在脑脊液的信号中；误诊的3例中，误诊为神经纤维瘤1例，误诊为室管膜瘤1例，另1例恶性外周神经鞘膜瘤术前误诊为良性神经鞘瘤。结论MRI表现典型的椎管内神经鞘瘤诊断较容易，表现不典型者易误诊，微小肿瘤以及完全囊变的肿瘤易漏诊，需仔细观察。

The Study of MRI Imaging on 50 Cases of Vertebral Canal Schwannoma

Objective To study the MR feature and improve the diagnosis accuracy of schwannoma.Methods Fifty patients with a surgical and pathological proved schwannomas were retrospectively reviewed.25 cases of male and 25 cases of female.49 benign schwannomas and 1 malignant schwannomas.All cases were made plain and enhancement scan.Results All 50 cases were intradural-extramedullary in location.44 cases of schwannomas before surgery were proved to be right, and the correct rate was 88%.3 cases were missed diagnosed and misdiag- nosed respectively.All 3 cases of misdiagnosed were in lower lumbar region,one with a diameter of only 5mm,two completely cystic degenerated tumors submerged in the high signal of CSF.Among 3 misdiagnosed cases,one was misdiagnosed as neurofibroma, one as ependymoma, another was a malignant schwannomas diagnosed as a benign tumor.Conclusion The schwannonas had many characteristic MR findings.Typical cases are easy for diagnosis. Cases with untypical performances are easy to misdiagnose.Micro tumors and completely cystic degenerated cases are easy to be miss-diagnosed,the cases need to be observed carefully.