局灶性脑皮层发育不良的MRI诊断

MRI Diagnosis of Focal Cortical Dysplasia

目的研究局灶性脑皮层发育不良(focal cortical dysplasia,FCD)的MRI表现特点。资料与方法回顾性分析23例经手术病理证实的FCD患者的MRI表现。常规行横断位、矢状位及垂直于海马长轴的斜冠状位扫描,获得T1WI、T2WI及液体衰减反转恢复序列(FLAIR)图像。结果23例FCD病灶均表现为一侧大脑半球内局限性病变。病灶区域皮质增厚18例,灰白质分界模糊20例,皮层下白质异常信号22例,脑回、脑沟形态异常14例,邻近蛛网膜下腔局限性扩大4例。T1WI、T2WI及FLAIR显示灰白质分界模糊分别为6例、20例及18例;皮层下白质异常信号分别为3例、16例及19例;脑回、脑沟形态异常分别为12例、10例及11例。结论FCD的MRI表现为皮质增厚、灰白质分界模糊、皮层下白质异常信号、脑回、脑沟形态异常及邻近蛛网膜下腔局限性扩大。T2WI及FLAIR显示灰白质界限、白质内异常信号较T1WI敏感,T1WI显示脑回、脑沟形态有一定的价值。

Objective To discuss the MR findings of focal cortical dysplasia（FCD）.Materials and Methods MR findings of 23 patients with FCD confirmed by operation and histopathology were reviewed retrospectively.Sagittal,axial and tilted coronal（perpendicular to the long axis of hippocampus）scan.T1-weighted,T2-weighted and fluid attenuated inversion recovery（FLAIR）images were obtained.Results All lesions were local and localized in unilateral hemisphere.MR images showed thick cortices in 18 patients,blurring of the gray/white matter junction in 20 patients,abnormal signal intensity in the subcortical white matter in 22 patients,broad gyri and abnormal sulci in 14 patients,focal enlargement of the overlying subarachnoid space in 4 patients.T1-weighted,T2-weighted and FLAIR images showed blurring of the gray/white matter junction in 6,20 and 18 patients,abnormal signal intensity in the subcortical white matter in 3,16 and 19 patients,abnormal gyral/sulcal patterns in 12,10 and 11 patients respectively.Conclusion MR imaging abnormalities such as increased cortical thickness,blurring of the grey/white matter junction,hyperintensity signal in subcortical white matter on FLAIR and T2-weighted images and abnormal gyral/sulcal patterns,which suggest the presence of FCD.T2-weighted and FLAIR images are superior to T1-weighted images for detection interface of the grey/white matter,abnormal signal in the subcortical white matter.T1-weighted images are suitable for delineating abnormal gyral/sulcal patterns.