ABSTRACT
Objective To explore the imaging characteristics and make the differential diagnosis of intraspinal extramedullary epidural lesions. Methods 23 cases with intraspinal extramedullary epidural lesions confirmed by puncture or surgical pathology were selected for retrospective analysis of the lesion morphology,MRI signs and the relationship between the lesion and surrounding tissues.Results Intraspinal extramedullary epidural lesions were more often located at thoracic spinal canal.The shapes of lesions were always various.The malignant tumors were irregular.It could damage the adjacent bone and grew surrounding the spinal cord.Leaping growth and multiple vertebral involvements could be seen in metastasis.The complex components of lesions were related to heterogeneous signal intensity on MRI,which could be presented with hypoGto hyperGintense on T1 WI and T2 WI.The angiolipoma showed hypoGto hyperGintense on T1 WI,and the hyperGintense signal could be suppressed with fatGsuppressed sequence.Meningioma tended to present with homogeneous signal on both T1 WI and T2 WI, with dural tail on contrast MRI.All of the lesions were moderately or significantly enhanced on contrast MRI.Conclusion Intraspinal extramedullary epidural lesions include a wide range of lesions,and the components of lesions are very complex.Among them,the distinctive MRI characteristics include the lesions containing fat and vascular components,besides malignant lesions invading adjacent tissues.Comprehensive analysis of the shape and signal of lesions,as well as the relationship between lesions,and surrounding structures is very helpful in differential diagnosis of intraspinal extramedullary epidural lesions.