MRI在听神经瘤检查中的作用探讨

The study of MRI examination of acoustic neuromas

目的 :探讨MRI在听神经瘤检查中的作用。方法 :2 0例听神经瘤均行MRI检查 ,取矢状位作定位像 ,行横断T1 WI、T2 WI扫描及矢状和冠状T1 WI/T2 WI扫描。均用造影剂Gd DTPA。结果 :肿瘤位于左侧 4例 ,右侧 1 6例。肿瘤直径 <2cm 4例 ,2 4cm 1 4例 ,>4cm 2例。T1 加权像呈等信号或低信号 ,T2 加权像呈高信号 ,出血或坏死可呈低高信号混杂。结论 :MRI是听神经瘤检查的首选方法 ,并在肿瘤的囊变、出血、周围情况了解上具有一定优越性 。

Objective:To discuss the examination parameters of acoustic neuromas. Method: The MRI features of 20 lesions 20 patients with acoustic neuroma had been analyzed retrospectively. The examinations were performed by a 1.5 Tesla superconducting magnet system transaxial T 1.T 2 weighted imagines and coronal or sagittal T 1.T 2 weighted imagines were obtained in each cases. 20 patients were examined with Gd DTPA. Result: 20 cases of acoustic neuroma were divided into three groups according to the tumor size:①1~2 cm(4 lesion);②2~4 cm(14 lesion);③over 4 cm(2 lesion).T 1 weighted imagines shovos the equal or low signal;T 2 weighted imagines shows the high signal.Low and high mixture signal will be shown when being hemorrhage or necrosis. Conclusion: Combining thin slice and Gd DTPA in MRI examination was the best method to find acoustic neuroma. MRI not only can find small intracanalicular tumors , but also has advantages in demonstrating the formation of cyst and hemorrhage, the compression of adjacent anatomical structures and the tumor vessels.