神经元和混合性神经元-神经胶质肿瘤的影像诊断——基于MR生理代谢成像的初步研究

The Imaging Diagnosis of Neuronal and Mixed Neuronal-Glial Tumors:Preliminary Study Based on Functional MR Imaging

目的探讨颅内神经元和混合性神经元-神经胶质肿瘤的磁共振波谱、灌注加权成像、扩散加权成像和磁敏感加权成像表现,提高术前诊断的准确性。方法回顾性分析6例经病理证实的神经元和混合性神经元神经胶质肿瘤的MRI表现,重点分析该类肿瘤MR生理代谢成像特征。结果神经节细胞胶质瘤及神经节细胞瘤各2例,乳头状胶质神经元肿瘤、胚胎发育不良性神经上皮肿瘤各1例。病变多为囊实性肿块,最大径平均为(3.98±1.26)cm,有不同程度强化,瘤周一般无或仅有轻度水肿。肿瘤多无明显扩散受限而表现为等低信号,实质区呈高灌注,其中1例为低灌注。胆碱有不同程度升高,氮-乙酰天门冬氨酸则多为降低表现,其中1例胆碱及氮-乙酰天门冬氨酸明显升高,磁敏感加权成像上肿瘤内有点片状低信号者2例。结论扩散加权成像、灌注加权成像及磁共振波谱等反映肿瘤生理代谢特征的MRI技术,对神经元和混合性神经元-神经胶质肿瘤的显示有一定特征性,结合常规MRI和临床表现能提高术前鉴别诊断能力。

Objective To explore functional MRI findings of intracranial neuronal and mixed neuronal-glial tumors, so as to improve preoperative diagnosis accuracy. Methods MRI findings of 6 patients with surgical pathology confirmed in- tracranial neuronal and mixed neuronal-glial tumors were analysed retrospectively. In particular, to focus on metabolic and physiological characteristics of tumors using functional MR imaging. Results Six tumors,including 2 cases of ganglioglio- ma,2 cases of gangliocytoma, 1 case of Papillary glioneuronal tumour and 1 case of dysembryoplastic neuroepithelial tumor were included in this study. Most lesions showed cystic solid masses which had clear borders, no or mild peritumoral ede- ma, and vax^cing degree of contrast enhancement. Average maximum diameter of tumors was （4.02 ＋ 1.16） cm. Most tumors showed no restricted diffusion and low signal on DWI images. PWI showed high-perfusion in all tumors except one. Metabolite changes within the treMors showed Cho increased and NAA decreased obvioLlsly. SWI images showed dot and striped low-intensity in 2 cases. Conclusion Functional MR, including DW1, PWI and MRS can reflect the characteris- tics of tumor metabolism, have certain value to differential diagnosis of neuronal and mixed neuronal-glial tumors. Com- bined with conventional MRI and clinical findings should be able to improve the preoperative diagnosis.