磁源性影像对颅内肿瘤患者初级体感皮质定位的研究

Localization of the primary somatosensory cortex in patients suffered from tumor within the skull by magnetic source imaging

目的:确定磁源性影像(MSI)对颅内肿瘤性病变患者脑初级体感皮质定位的价值。材料与方法:6例颅内肿瘤接近体感皮质的患者,其中男4例,女2例,年龄15-68岁,平均46岁。对患者双侧腕部正中神经进行电刺激。用306通道全头型生物磁仪(MEG)进行脑磁场测量。MRI设备使用GE公司生产的1.5T Signa Horizon成像系统。结果:所有受试者均出现M20波峰(电刺激腕部正中神经后20ms左右出现的体感诱发磁场)及M35波峰(电刺激腕部正中神经后35ms左右出现的体感诱发磁场),M20波峰潜伏期为21.2±0.9ms。MRI显示病变侧脑沟明显变窄。MSI明确地显示出脑体感皮质与肿瘤的立体关系,借此外科医师很容易地识别出中央沟的位置。结论:MSI对帮助术前制定的手术计划、术中的程序以及提供肿瘤与脑功能区的立体关系有重要意义。

Objective: To study the value of magnetic source imaging(MSI) in defining the somatosensory cortex in patients with tumor within the skull. Methods: Six patients (4 men and 2 women) suffered from tumor near the somatosensory cortex within the skull were examined by VectorView 306-channel whole-scale biomagnetometer (MEG) made by 4D Neu-roimaging Company(U.S.A) and Signa 1.5T MR unit manufactured by GE Company(U.S.A). The age ranged from 15 to 68 years old with an average of 46 years old. Giving all the patients left and right wrist median nerve electric stimulation, it can evoke functional brain activity-primary somatosensory cortex excitation, the excited cortex generates weak magnetic field out of the brain, the weak magnetic field can be measured by magnetoencephalography. To superimpose the data obtained by MEG on MRI, we can get the MSI. Results: The peaks of M20 and M35 were seen in all 6 patients. The latent period of the M20 peak is 21.2±0.9ms. MRI shows the sulci of brain around the lesion become narrow. To combine the patient's M20 on MRI, we can get the location of the hand areas of the primary somatosensory cortex. The three-dimensional relationship between the tumor and the localization of the primary somatosensory cortex is shown very clearly in MSI. It is easy to identify the central sulci. Conclusion: It is helpful for surgeons to make operation plan before operation and intraoperation and provide the three-dimensional relationship between the tumor and localization of the primary somatosensory cortex by MSI.