眼眶淋巴瘤多模态影像分析

Multimodal imaging analysis of orbital lymphoma

目的:探讨眼眶淋巴瘤多模态影像学特征。方法:回顾性分析27例经病理证实为眼眶淋巴瘤患者的治疗前MRI、CT增强扫描及^(18)F-FDG PET/CT影像。评估内容包括病灶的MRI特征、CT增强扫描特征及最大标准摄取值(SUVmax)。结果:总共收集27例(34眶)患者,其中25例(31眶)行眼眶MR扫描,10例(13眶)行CT增强扫描及^(18)F-FDG PET/CT扫描。病变多位于眶隔前区(15.38%)、泪腺区(23.08%)及肌锥区(21.54%)。病灶在压脂T_(2)WI上,11例呈均匀稍高信号,13例呈等信号,1例呈混杂高信号;压脂T_(1)WI上,24例呈等信号,1例呈稍低信号;压脂T_(1)WI增强扫描上,15例呈中度均匀强化,8例为轻度均匀强化,2例为不均匀强化;7例可见骨质破坏。10例行CT增强扫描及^(18)F-FDG PET/CT扫描患者中,病理组织类型为黏膜相关淋巴组织边缘区B细胞(MALT)淋巴瘤5例,弥漫大B细胞淋巴瘤(DLBCL)5例,其中1例DLBCL患者在CT上表现为不均匀密度,其余9例表现为均匀密度。两种病理类型病灶的△CT值差异无统计学意义(统计值0.60,P>0.05)。DLBCL与MALT淋巴瘤病灶的SUVmax差异具有统计学意义[6.40(5.40~7.10)vs.11.40(9.63~25.60),P=0.009]。结论:眼眶淋巴瘤病变多位于眶隔前区、泪腺区及肌锥区。MRI上病灶压脂T_(1)WI多呈等信号,压脂T_(2)WI呈等或稍高信号,增强扫描呈轻到中度强化;在CT上表现为均匀密度,增强扫描呈轻到中度强化,病灶的强化程度对鉴别DLBCL和MALT淋巴瘤无帮助。在^(18)F-FDG PET/CT中,DLBCL的SUVmax较高,病灶的SUVmax有助于鉴别DLBCL和MALT淋巴瘤。

Objective:To explore multimodal imaging features of orbital lymphoma.Methods:The MRI,contrast-enhanced CT scans and ^(18)F-FDG PET/CT of 27 patients with pathologically confirmed orbital lymphoma before treatment were retrospectively analyzed.The evaluation contents included the lesion's MRI characteristics,CT enhancement characteristics and maximum standard uptake value(SUVmax).Results:Among the 27 patients(34 orbits),25 patients(31 orbits)underwent orbital MR scans,and 10 patients(13 orbits)underwent contrast-enhanced CT scans and ^(18)F-FDG PET/CT scans.The lesions were primarily located in the preseptal space(15.38%),lacrimal gland region(23.08%)and extraocular muscle cone region(21.54%).On fat suppressed T_(2)-weighted images,11 cases showed homogeneous slight hyperintensity,13 cases showed isointensity,and 1 case was heterogeneous hyperintensity.On fat suppressed T_(1)-weighted images,24 cases showed isointensity,and 1 case showed slight hypointensity.On contrast-enhanced fat suppressed T_(1)-weighted images,15 cases showed moderate homogeneous enhancement,8 cases showed mild homogeneous enhancement,and 2 cases showed heterogeneous enhancement.7 cases showed bone destruction.Among the 10 patients who underwent contrast-enhanced CT scans and ^(18)F-FDG PET/CT,5 cases were mucosa-associated lymphoid tissue(MALT)lymphoma and 5 cases were diffuse large B-cell lymphoma(DLBCL).1 case of DLBCL showed heterogeneous density on CT,and the remaining 9 patients showed homogeneous density.There was no significant difference in the△CT value of orbital lesions between MALT and DLBCL(P=0.60,P>0.05).The SUVmax of the lesions was significantly different between DLBCL and MALT lymphoma[6.40(5.40~7.10)vs.11.40(9.63~25.60,P=0.009].Conclusion:The lesions are mostly located in the preseptal space,lacrimal gland region and extraocular muscle cone region.The lesions show isointensity on fat suppressed T_(1)-weighted images,isointensity or slightly hyperintensity on fat suppressed T_(2)-weighted images,and mild to moderate enhancement.On CT,the lesions show homogeneous density and mild to moderate enhancement.The enhancement degree of orbital lesions is unhelpful for differentiating DLBCL from MALT lymphoma.On ^(18)F-FDG PET/CT,the SUVmax of DLBCL is high,and the SUVmax of the lesion is helpful to distinguish DLBCL from MALT lymphoma.