眼眶孤立性纤维瘤的CT及MRI特点

目的 探讨眼眶孤立性纤维瘤(SFT)的CT及MRI表现特点.方法 回顾性分析7例经手术病理证实的眼眶SFT的CT及MRI资料.结果 7例SFT均为单发,边缘界限清晰,病灶最大直径17～4 5 mm;跨肌锥内、外生长1例,肌锥外2例,肌锥内4例. 6例接受CT平扫,均表现为等密度肿块,内未见出血、囊变及钙化. 4例接受MR平扫,其中3例T1WI呈等信号,1例呈稍低信号；3例T2WI呈稍高信号,1例呈等信号；2例于T2Wl可见小囊样高信号囊变区；4例于T1WI或T2WI可见管状或分支状的血管流空信号. 6例CT或MRI增强后明显强化,其中3例CT强化方式为快进快出.结论 增强后病灶呈快进快出的强化方式及MR见流空信号是眼眶SFT的特征性影像学表现.

CT and MRI features of orbital solitary fibrous tumor

Objective To investigate CT and MRI features of orbital solitary fibrous tumor (SFT). Methods CT and MRI data of 7 patients with orbital SFT confirmed by surgery and pathology were retrospectively analyzed. Results All 7 lesions were found as solitary, well-defined mass, ranging in size from 17 mm to 45 mm. One lesion located in intraconal and extraconal of the orbit, 2 located in extraconal of the orbit and 4 in intraconal of the orbit. All 6 lesions examined by plain CT scan showed isodensity mass without hemorrhage, cystic change nor calcification. All 4 lesions on plain MRI present as isointense signal (3 lesions) or slightly hypointensity (1 lesion) on T1WI, slightly hyperintense (3 lesions) or isointense (1 lesion) on T2WI. Little cystoid hyperintense cystic degeneration regions on T2WI was detected in 2 lesions. Fistular flow voids signal on T1WI or T2WI was noticed in 4 lesions. Six lesions showed marked homogeneous enhancement on contrast CT or MRI. Three lesions examined by contrast enhancement CT showed intensification of contrast quickly in and quickly out. Conclusion Quickly in and quickly out enhancement and flow voids signal on MRI are the distinctive imaging findings of orbital solitary fibrous tumor.