周围神经鞘瘤的CT和MRI表现

CT and MRI Features of Peripheral Neurilemoma

目的:探讨周围神经鞘瘤的CT和MRI表现。方法:回顾性分析13例经病理证实的周围神经鞘瘤的CT和MRI表现,其中发生在颈椎和胸椎椎间孔内的2例、颈部1例、枕部1例、纵隔1例、胸壁1例及下肢7例。结果:肿瘤均呈椭圆形,边界清楚光滑,沿神经走行方向生长,2例有邻近椎间孔扩大。CT显示肿瘤包膜密度高,包膜内肿瘤组织密度低于肌肉组织。MRI T1WI显示肿瘤呈中～低信号,T2WI呈不均匀高信号,增强后有不均匀强化。其中显示靶征4例,神经出入征3例,脂肪包绕征8例,脂肪尾征7例及脑脊液尾征1例。结论:周围神经鞘瘤的影像学表现有一定特征性,CT和MRI对诊断有重要价值。

Objective：To analyze the CT and MRI features of peripheral neurilemoma. Methods：The CT and MRI fea tures of 13 patients with histopathology proved peripheral neurilemoma were retrospectively analyzed. The location of the tumor was cervico-thoracic intervertebral foramen （2 cases）,neck,occipital region,mediastinum,chest wall for 1 case each, and lower limb （7 cases）. Results：All of the tumors were oval shaped, well-defined and with the extent along the nerve distribution. Enlargement of intervertebral foramen could be assessed in 2 cases. The capsule of tumors showed hyper-attenuated, the density of intra-capsular tumor mass was lower than that of muscle. The masses showed iso-/hypo signal intensities on MR T1WI and heterogeneous hyper-intensities on T2WI. After contrast administration, the lesions showed inhomogeneous enhancement,with ＂target＂ signs in 4 cases, nerve entering and exiting the tumor in 3 cases, fat-encircling sign in 8 cases, fat-tail sign in 7 cases, cerebrospinal-fluid tail sign in 1 case. Conclusion： Characteristic imaging findings could be revealed in peripheral neurilemoma,which might provide significant information for the diagnosis.