视神经胶质瘤的影像学表现

Imaging performance of optic gliomas

目的分析视神经胶质瘤的CT、MRI及超声影像学资料，探讨其在诊断和鉴别诊断中的价值。方法回顾分析1991年5月至2012年5月在天津医科大学眼科医院及第二附属医院眼科经手术病理证实的视神经胶质瘤30例，其中CT检查30例，MRI检查20例，超声检查30例。结果CT表现为视神经肿大，其中椭圆形12例，梭形12例，类圆形3例，坛状2例，串珠状1例。局限于眶内段10例，眶内段且累及视神经管20例。边界清28例，边界不甚清楚2例。密度较均匀25例，内部有低密区5例。增强扫描6例，肿瘤呈轻到中等强化，可辨认出颅内蔓延1例。MRIT1WI与脑实质相比呈等或低信号，T2WI呈等或高信号，5例增强可见颅内蔓延。B型超声病变呈中等回声15例，弱回声12例，缺乏内回声3例。视乳头向前突起9例。彩色多普勒血流成像6例，4例病变内见少量血流信号，2例未见血流信号。结论CT、MRI及超声检查对于视神经胶质瘤的诊断具有重要地辅助意义，但各有优缺点，其中MRI对视神经胶质瘤的定位、定性诊断优于CT及超声。

Objective To evaluate CT, MRI and Ultrasonic imaging performance and their clini- cal significance of optic gliomas. Methods CT, MRI and US images of 30 patients with pathologi- cally confirmed optic gliomas were analyzed retrospectively. CT scanning and Ultrasonic were per- formed in 30 patients, whereas MRI was performed in 20 patients. Results Of the 30 cases with optic gliomas, a fusiform thickening of optic nerve was found on CT and/or MRI images in 12, an ovoid mass of the optic nerve in 12, a circular mass of the optic nerve in 3, an altar mass of the optic nerve in 2, and a beads string mass in 1 case. Enlargement of intraorbital segments of optic nerve was seen inl0 cases, intraorbital and optic canal involved together was seen in 20 cases. Twenty-eight cases showed a clear boundary and only 2 cases didn＇ t. CT scanning of 25 cases per- formed iso-density mass whereas 5 cases showed a low density within the area. Postcontrast CT was performed in 6 patients, showed a medium enhancement of optic nerve, and intracranial expan- sion in 1 case was visible. The swelling optic nerve showed a medium or low signal on Tl-weight- ed images, high signal on T2-weighted images compared with brain parenchyma. Intracranial expan- sion could be seen in 5 patients using contrast administration. Fifteen cases of optic gliomas per- formed moderate echo on B ultrasonic, and weak echo in 12 cases, lack of echo in 3 cases, and protruding nipple was seen in 9 cases. A small amount of blood flow signals could be seen in 4 cases in all the 6 patients, except 2 cases. Conclusions CT, MRI and ultrasound are important for the diagnosis of optic glioma. Though some disadvantages, MRI may be the best method of inspec- tion of the disease.