眼眶淋巴瘤的MRI征象

MRI Features of Orbital Lymphoma

目的探讨眼眶淋巴瘤的MRI特点,提高对本病的认识和术前诊断准确率。资料与方法回顾性分析8例经手术病理证实的眼眶淋巴瘤的MRI表现,包括病变部位、数量、形态、大小、MRI信号及对邻近结构的侵犯。结果 8例患者中,6例为单侧,2例为双侧。4例位于眼眶前部,包括眼睑、泪腺及眼球周围,1例位于肌锥外间隙,4例呈弥漫性,位于眼眶前部及肌锥内外间隙,并不同程度地包绕眼球;1例可见眼眶骨质破坏,并突破眶骨向颅内外蔓延;8例均未见囊变、坏死。6例平扫T1WI呈等信号,2例呈稍低信号;6例T2WI呈均匀稍高信号,2例呈等信号;增强扫描后6例呈与眼外肌信号一致的中度均匀强化,2例为轻度均匀强化。结论眼眶淋巴瘤的MRI表现有一定的特征性,好发于眶隔前部,并向眶内侵犯;单侧多见,也可以双侧多发;呈多形性、塑形性、浸润性生长,信号多均匀,增强扫描多呈轻中度强化,少见骨质破坏,掌握其MRI表现有助于术前定性诊断。

Purpose To study the MR features of orbital lymphoma in order to improve its preoperative diagnostic accuracy. Materials and Methods The MRI findings of 8 patients with primary orbital lymphoma proved pathologically were analyzed retrospectively in the aspects of diseased region, number, appearance, size, MRI signal and the invasion to the adjacent structure. Results Unilateral masses were found in 6 cases and bilateral masses in the other 2 cases. There were 4 cases located in the front of the eye socket, including eyelids, tear ducts, and around the eye; 1 case was located in the muscle cone outer clearance; 4 cases were diffusely located in the front orbital muscle cone inside and outside the gap, and surrounded the eyeballs in different degrees. One case showed orbital bony destruction and expanded to intracranial and extracranial tissue. No capsules and necrosis were found in the 8 cases. Six cases showed isointense signals and the other 2 showed slightly low signals on T1WI; 6 cases presented slightly hyperintense signals and the other 2 were isointense on T2 WI. On contrast-enhanced scan, 6 lesions showed moderate homogeneous intensity similar to that of the extraocular muscle, and the other 2 lesions showed slight homogeneous intensity. Conclusion The MRI of orbital lymphoma have the following characteristics such as frequent occurrence in the front of orbital septum and invasion into the orbit, often unilateral mass and sometimes bilateral multiple masses, polymorphism, shaping and invasive growth, homogenous signals, mild to moderate enhancement on enhanced scan, and rarely-seen bone destruction. Recgnizing these MRI features of orbital lymphoma is useful in preoperative diagnosis.