人脑颅神经的磁共振影像研究

MR imaging of the cranial nerves: Imaging anatomic study

目的 探讨 1.5TMR在 12对颅神经检查中应用与限度。方法 采用 1.5TMR扫描仪 (Picker ,Eclipse)对 6 0例健康志愿者和 15例头颅标本进行MR检查。MR影像解剖与解剖标本相对照。结果 嗅球和嗅束可在冠状面上显示。视神经全程在与视神经长轴平行的斜矢状面上显示最佳。动眼神经和外展神经只在与背景组织对比较大的区域可确定。滑车神经由于过细而不能显影。在冠状面和横断面上 ,三叉神经均易确定。MR影像易于判断面、前庭蜗神经的分支。颞骨内面神经可在斜矢状面上显示。舌咽、迷走、副和舌下神经可见于横断面 ,特定的斜平面有利区分该组神经。结论 1.5TMR可进行细微的颅神经解剖学研究。恰当的方法可提供理想的影像。

Objective To investigate the applicability and limitation of 1.5T MR unit on MR imaging of 12 cranial nerves. Methods MR examinations were performed on 60 healthy volunteers and 15 formalin fixed adult heads of cadave with 1.5T MR unit (PICKER, eclipse). The specimens of cadaver head were dissected. The anatomy depicted on MR imaging was compared with the dissected specimens. Results The olfactory bulbs and tracts were revealed on coronal plane. The whole course of the optic nerves was well identified on oblique sagittal plane, which porallelled to the long axis of the optic nerve. The oculomotor and abducent nerves were only detectable in some regions where the contrast with the surrounding structures was greater. The trochlear nerves were too thin to be revealed. The trigeminal nerves were easy recognized on axial and coronal planes. The branches of the facial and vestibulocochlear nerves could be easily visualized on Fast SE MR imaging. The intratemporal part of the facial nerves could be revealed on oblique sagittal plane parallel to them. The glossopharyngeal, vagus, accessory and hypoglossal nerves were detectable on axial plane, and special oblique plane were helpful to distinguish them separately. Thin sections, fat suppression, Gd DTPA enhancement and 3D reconstruction offered additional information. Conclusion 1.5T MR unit can show detailed anatomy of the cranial nerves. Proper protocols could provide optimal visualization.