颅内原发性淋巴瘤的CT、MRI表现并MRS分析

Manifestations of the CT,MRI and MRS Analysis of Primary Intracranial Lymphoma

目的分析颅内原发性淋巴瘤CT、MRI及磁共振波谱成像(MRS)表现,探讨其影像诊断要点。方法回顾性分析经病理及免疫组织化学证实的20例颅内原发性淋巴瘤的临床及影像学资料。20例均行MR平扫、扩散加权成像(DWI)及增强扫描,其中8例行MRS分析。结果20例均为弥漫性大B细胞淋巴瘤,临床首发症状以头痛、一侧肢体活动障碍为主。20例中,单发14例(70%),多发6例(30%),男女比例1∶1;CT平扫多表现为均匀等密度肿块;MR扫描共检出病灶35个,其中25个位于幕上,8个位于幕下,1个位于右侧大脑脚,1个位于左侧顶骨;MR平扫信号多与脑皮质相似,所有病灶在DWI序列上均呈扩散受限表现,增强扫描以明显均匀强化为主;8例行MRS分析,其中6例(75%)N-乙酰天门冬氨酸(NAA)峰轻度降低,4例(50%)出现自由脂(Lip)峰。结论MR平扫、DWI及增强扫描结合MRS分析能够诊断绝大多数典型颅内原发性淋巴瘤,为临床治疗方案的制定提供重要参考。

Objective Analyzed the CT,MRI and MRS manifestations of primary intracranial lymphoma,and to study the key points of early imaging diagnosis.Methods We conducted retrospective analysis for the clinical and imaging data of20 patients with primary intracranial lymphoma,which has been confirmed by pathology and immunohistochemistry(All of the patients underwent MR plain scan,DWI and enhanced scan.Eight of them underwent MRS analysis as well).Results All of the patients were diagnosed with diffuse large B-cell lymphoma,with the main first clinical symptoms of headache and hemiplegia.Among the 20 cases,sex ratio was 1:1,14 cases were simple(70%),6 cases were multiple(30%).Primary intracranial lymphoma mainly showed uniform density on CT plain scan.Thirty-five lesions were detected during MR scan,of which 25 lesions were located in supratentorial compartment,8 lesions werelocated in infratentorial compartment,1 was found in the right cerebral peduncle,and 1 was found in the left parietal bone.The signals of MR plain scan were mostly similar to the cerebral cortex.All lesions showed diffusion restriction pattern on DWI sequence,while enhanced scanning mainly revealed significant and uniform enhancement.Eight cases underwent MRS Analysis,among which 6 cases(75%)had a slight decrease in NAA peak,and 4 cases(50%)had a Lip peak.Conclusion MR plain scan,DWI and enhanced scan,combined with MRS analysis can be applied to diagnose most typical primary intracranial lymphomas and provide important evidences for the non-surgical clinical treatment options.