^1H磁共振波谱在胶质瘤放疗后复发和放射性脑坏死鉴别中的初步应用

1H magnetic resonance spectroscopy (1H MRS) in the initially differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis

目的 探讨质子磁共振波谱 (1HMRS)对胶质瘤放疗后复发和放射性脑坏死鉴别诊断的价值。方法 15例有脑部放疗史 ,临床及CT、MRI难以判断为肿瘤复发或放射性脑坏死的患者 ,5例病史明确的放射性脑坏死的患者 ,均行1HMRS检查。结果 前 15例经手术证实 ,14例为胶质瘤 ,1例放射性脑坏死 ,1HMRS诊断正确。 (1) 14例胶质瘤在1HMRS上均表现为明显增高的胆碱(Cho)峰 ,氮乙酰门冬氨酸 (NAA)、肌酸 (Cr)峰下降或消失 ,Cho/Cr比值升高 ,NAA/Cr比值降低 ;12例出现乳酸 (Lac)峰。 (2 )放射性脑坏死表现为 :5例Cho、NAA、Cr下降或消失 ,出现脂质 (Lipid)峰 ;1例Cho、NAA、Cr峰均消失 ,仅表现一较平坦的曲线 ,无Lac峰。结论 1HMRS对胶质瘤放疗后复发和放射性脑坏死的鉴别有重要价值。

Objective To evaluate 1*'H magnetic resonance spectroscopy (1H MRS) in the differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis. Methods Fifteen patients who had clinical and CT, MRI changes that suggested a diagnosis of delayed cerebral necrosis or recurrent brain tumor after radiation therapy and 5 patients who had a definite clinical diagnosis of delayed cerebral necrosis underwent single voxel MR spectroscopy simultaneously both in the lesion′s region and the contralateral side. Results Of the former 15 cases who proved by surgicopathology, 14 cases were gliomas,1case was delayed cerebral necrosis, and their etiologic diagnoses of 1*'H MRS were correct. (1)1H MRS in 14 cases with gliomas exhibited specific spectral peaks including prominent choline-containing compounds (Cho), decreased or absent acetylaspartate(NAA) and total creatine (Cr),and the metabolic ratios showed significantly increased Cho/Cr, decreased NAA/Cr. Twelve cases showed abnormal lactate (Lac). (2)Among 6 cases with delayed cerebral necrosis, 5 cases exhibited decreased or absent Cho, NAA, Cr, and abnormal Lipid, 1 case showed absent Cho, NAA, and Cr with a flat curve without Lac. Conclusion 1H MRS was positively claimed for differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis.