桥小脑角区脑膜瘤与听神经鞘瘤动态MRI的鉴别诊断

A Study of Dynamic Contrast-Enhanced MR Imaging in the Differential Diagnosis of Meningioma and Schwannoma in Cerebellopontine Angle Region

目的:研究桥小脑角区脑膜瘤及听神经鞘瘤磁共振动态增强(MRI DCE)及延迟扫描的信号变化规律及其鉴别诊断价值。方法:对15例脑膜瘤和 10 例听神经鞘瘤行 SE序列 T1WI扫描,团注对比剂后即刻采集图像,并分别于 3、6、9、12、15、30min及1、1.5、2、2.5、3.5、6.5、9.5、19、24、30h行动态及延迟扫描。分别计算两种肿瘤在各时相的平均信号强度,绘制时间 信号强度曲线。并测量计算两种肿瘤的强化峰值(MSI)、峰值时间(Tp)、最大增强率(MCER)、半衰期(HL)、斜率03(S03),并经 t检验进行比较。结果:听神经鞘瘤的强化程度较高,呈速升缓降型;脑膜瘤的强化程度较低,呈速升速降型。听神经鞘瘤的MSI及MCER均高于脑膜瘤;Tp、HL及 S03 二者差异均无显著性意义。结论:行 MRI DCE及延迟扫描,有助于脑膜瘤及听神经鞘瘤的鉴别诊断。

Objective:To study the characteristics of the signal intensity of meningioma and schwannoma on dynami-cenhanced and delayed MR imaging and assess their clinical value in differential diagnosis.Methods:15 patients with meningiomas in cerebellopontine angle region and 10 patients with schwannomas were performed SE T1WI scan.Images were taken before and after bolus injection immediately.Dynamic and delayed scans were taken 3,6,9,12,15,30 minintes and 1, 1.5, 2, 2.5, 3.5,6.5,9.5,19,24,30h after injection.Signal intensity of lesions at different phase was measured and the time-intensity curve was drawn. The max of signal intensity (MSI),time to peak (Tp),max of the contrast enhanced rate (MCER),half of the life (HL),slope of 0～3 minute (S 03 ) were statistically determined respectively.Results:Enhancement of meningioma was less remarkable than that of schwannoma.Schwannoma enhanced intensely and washed out slowly,while meningioma enhanced intensely and washed out quickly.MSI and MCER of schwannoma were higher than that of meningioma,while there was no significant difference for Tp,HL and S 03 between schwannoma and meningioma.Conclusion:Dynamic contrast-enhanced and delayed MRI is a useful technique for the differential diagnosis of schwannoma and meningioma.