眼球孤立性脉络膜血管瘤的HR-MRI表现

HR-MR Imaging of Circumscribed Choroidal Hemangioma

目的 探讨眼球孤立性脉络膜血管瘤的高分辨率磁共振 (HR MRI)影像学特征 ,进一步提高诊断水平。资料与方法 回顾性分析诊断明确的孤立性脉络膜血管瘤 16例共计 17个病灶的位置、数目、形态、大小、MRI信号、强化情况、有无合并视网膜脱离及有无视神经和眼外侵犯等。所有病例均行HR MRI及增强扫描 ,部分病例行脂肪抑制。结果 17个病灶中的 16个呈扁丘状位于眼球内壁的后极。 15个病灶厚度 <5mm ,平均厚度为2 .9mm。病灶边缘清晰 ,T1WI上呈轻度高信号者 16个 ,T2 WI上呈等信号者 15个 ,增强扫描显著强化者有 12个。 3例合并视网膜脱离 ,在T2 WI上多呈等信号 ,T1WI上呈轻度高信号者 ,均无强化。无视神经及眼外侵犯病例。结论 94 %孤立性脉络膜血管瘤的HR MRI表现具有特征性 ,表现为位于眼球内壁后极的较小、基底较宽、边缘清晰的扁丘状病灶。其T1WI信号高于玻璃体 ,T2 WI信号等于玻璃体 ,增强扫描瘤体显著强化。明确其HR MRI影像学特征有助于临床与恶性葡萄膜黑色素瘤相鉴别 。

Objective To discuss high resolution MRI (HR-MRI) features of circumscribed choroidal hemangiomas.Materials and Methods HR-MRI findings in 16 patients with clinically-confirmed circumscribed choroidal hemangiomas (17 lesions) were retrospectively analyzed. The observation was focused on the site, number, shape, size, MR signal and enhancement of the lesions. The presence or absence of retinal detachment and extra-ocular invasion was also observed. HR-MRI and enhanced scanning was performed in all patients, some patients received additional fat suppression sequence.Results Of 17 lesions, 16 were located at the posterior pole of eyeball inner wall and presented as flat dune-like shadow. The thickness of 15 lesions was below 5mm (mean 2.9mm). The lesion had a clear border, displayed as slight high signal on T 1WI (n=16) and iso-signal on T 2WI (n=15) with marked enhancement (n=12). Retinal detachment was accompanied in 3 cases, with the subretinal fluid being manifested as iso-signal on T 2WI and slight high signal on T 1WI without enhancement. No involvement of optic nerve or extra-ocular structures was found. Conclusion Most circumscribed choroidal hemangiomas have certain characteristics on HR-MRI. The lesion is usually located at the posterior pole of eyeball inner wall with a sharp border, flat dune-like shape and a thickness less than 5mm. The lesion's signal is higher than that of vitreous body on T 1WI, while as same as that of vitreous body on T 2WI. Marked enhancement can be demonstrated after contrast injection. Knowledge of HR-MRI features of the circumscribed choroidal hemangiomas is very helpful in differentiating it with malignant uveal melanomas, and unnecessary surgery can be avoided in some cases.