氢质子MR波谱对弥漫性轴索损伤的评估

背景:目前在弥漫性轴索损伤的临床诊断和伤情评估上,CT和常规MRI的作用非常有限.目的:验证氢质子MRI波谱技术在弥漫性轴索损伤临床诊断及预后评估中的价值.设计、时间及地点:前瞻性临床对照观察,于2002-10/2007-09在重庆医科大学附属第一医院神经外科及放射科完成.对象:纳入63例颅脑损伤患者,根据MRI检查结果分为2组,弥漫件轴索损伤组27例,非弥漫件轴索损伤组36例:再利用单纯随机抽样法选择20名健康成年人作为正常对照.方法:患者入院后,按常规进行治疗,一旦生命体征和意识情况允许,立即行包括液体衰减反转恢复序列在内的磁共振影像学检查,并在此同时行氢质子MR波谱检查,氢质子MR波谱检查数据进行后期工作站分析,并结合临床情况进行分析.主要观察指标:胼胝体膝部、压部和基底核N-乙酰天冬氨酸/肌酸和磷酸肌酸、胆碱复合物/肌酸和磷酸肌酸、肌醇/肌酸和磷酸肌酸以及谷氨酸和谷氨酰胺/肌酸和磷酸肌酸等指标.结果:与对照组和非弥漫性轴索损伤组相比,弥漫性轴索损伤组胼胝体膝部、压部和基底核出现N-乙酰天冬氨酸/肌酸和磷酸肌酸降低及胆碱复合物/肌酸和磷酸肌酸升高(P<0.05～0.01),胼胝体膝部和压部出现肌醇/肌酸和磷酸肌酸及谷氨酰胺/肌酸和磷酸肌酸升高(P<0.05).与对照组相比,非弥漫性轴索损伤组出现胼胝体膝部胆碱复合物/肌酸和磷酸肌酸升高和压部N-乙酰天冬氨酸/肌酸和磷酸肌酸降低(P<0.01),但变化程度比弥漫性轴索损伤组低.弥漫性轴索损伤组胼胝体膝部的胆碱复合物/肌酸和磷酸肌酸和伤后原发昏迷时间呈正相关(r=0.824,P<0.01).结论:胼胝体膝部、压部和基底核各氢质子MR波谱指标可作为弥漫性轴索损伤有效的诊断指标.氢质子MR波谱中的胆碱复合物/肌酸和磷酸肌酸等指标可以很好地反映伤后组织学的改变,是临床伤情预测的灵敏指标.

Evaluation of diffuse axonal injury by proton magnetic resonance spectroscopy

BACKGROUND: At present, traditional modalities of neuroimaging, such as CT and MRI, is very limited in the diagnosis and severity estimation of diffuse axonal injury (DAI).OBJECTIVE: To investigate the value of proton magnetic resonance spectroscopy (1HMRS) in the diagnosis and prognosis of DAI.DESIGN, TIME AND SETTING: Prospective clinical controlled observation. The study was performed at the Department of Neurosurgery, and Department of Radiology, First Affiliated Hospital of Chongqing Medical University between October 2002 and September 2007.PARTICIPANTS: A total of 63 subjects with traumatic brain injury were enrolled and divided into DAI group (n=27) and non-DAI group (n=36) according to the result of MRI. In addition, 20 healthy persons were served as control group.METHODS: Demographic and clinical data were recorded on admission and neuroimaging examinations including fluid attenuated inversion recovery were carried on according to carefully designed procedures, in addition, 1HMRS was performed and the data were analyzed in combination with clinical condition.MAIN OUTCOME MEASURES: The ratios of N-acetyl aspartate (NAA)/creatine (Cr) and creatine phosphate (Cr), Choline compound (Cho)/Cr, myoinositol (mlNs)/Cr, and glutamic acid (GIx)/Cr at genu and splenium of corpus cellosum, and basal ganglia were quantified using 1HMRS.RESULTS: Compared with control and non-DAI groups, DAI group had decreased NAA/Cr and increased Cho/Cr at genu and splenium of corpus callosum, and basal ganglia (P < 0.05- 0.01), as well as increased mlNs/Cr and Glx/Cr at genu and splenium of corpus cellosum (P < 0.05). Non-DAI group also showed decreased NAA/Cr at splenium and increased Cho/Cr at genu of corpus callosum compared with control group (P < 0.01), but the change degree was less than DAI group. A positive correlation between Cho/Cr at genu of corpus callosum and the peded of primary unconsciousness was identified in DAI group (r=0.824, P < 0.01). CONCLUSION: The 1HMRS indexes at genu and splenium of corpus callosum, and basal ganglia could serve as effective indexes for the diagnosis of DAI. The Cho/Cr could well reflect histological changes following injury and act as sensitive index to predict clinical injury.