摘要
目的:探讨Gd-DTPA增强MRI对听神经瘤的诊断价值。材料与方法:搜集经手术、病理证实的26例听神经瘤的MRI表现,其中5例为微小听神经瘤。全部病例均作了Gd-DTPA增强扫描。结果:本组26例听神经瘤中,5例肿瘤局限于内听道内。MRI表现为:①T1WI显示患侧第Ⅶ、Ⅷ神经束局部结节状增粗,呈稍低信号;②T2WI肿瘤呈稍高信号。③注射Gd-DTPA增强扫描呈明显均匀结节状强化。另21例为大的听神经瘤。MRI表现为:①肿瘤主体在桥小脑角区,T1WI呈稍低或稍低、低混杂信号,T2WI呈高信号或稍高、高混杂信号;②肿瘤以第Ⅶ、Ⅷ神经束为中心生长,患侧第Ⅶ、Ⅷ神经束较对侧增粗,与肿瘤无明确分界,两者信号变化一致;③增强扫描肿瘤实质呈不均强化,囊变区无强化。结论:MRI是诊断听神经瘤的有效方法,Gd-DTPA增强扫描对微小听神经瘤尤为重要。
Objective:To evaluate Gd-DTPA-enhanced MRI in the diagnosis of acoustic neuroma.Materials and Meth-ods:The MRI findings of 26acoustic neuromas from26cases verified by operation and pathology were analyzed.Of them there were5small acoustic neuromas and all of the26cases were studied with Gd-DTPA.Result:In26cases,5cases were located in internal auditory canal.The MRI findings of small acoustic neuroma were:①Focal nodular enlargement of theⅦ,Ⅷnerves and showed slightly hypointense on T 1 WI;②Slightly hyperintense on T 2 WI;③Homogeneous nodular enhanced after injection of Gd-DTPA on T 1 WI.The other21cases were big acoustic neuroma.The MRI findings were:①The main tumor mass of the21cases were located in CPA.Acoustic tumors demonstrated slightly hypointense to mixed hypointense on T 1 WI and hyperintense or slightly mixed hyperintense on T 2 WI;②TheⅦandⅧnerves on the affected side were markedly thick-ened and the tumor grew around with the nerves as the center.There was usually no clear demarcation between the nerve and the tumor.The signal intensity was the same between them;③The solid portion of the tumor after using Gd-DTPA usu-ally enhanced inhomogeneously but cystic areas showed no enhancement.Conclusion:MRI is a very useful method in the di-agnosis of acoustic neuromas,Gd-DTPA enhancement is important especially for diagnosis of small acoustic neuroma.
出处
《中国临床医学影像杂志》
CAS
2002年第1期1-3,共3页
Journal of China Clinic Medical Imaging
