磁共振氢波谱显示海洛因海绵状白质脑病的特征

背景:以往磁共振波谱研究多用点解析波谱或单体素波谱,其兴趣区主要集中在MRI可见的病灶区,不能显示病灶边缘区的改变状况,而化学位移成像磁共振氢波谱(1H-MRS)检测方法可将检测范围扩大至整个脑部区域。目的:观察海洛因海绵状白质脑病患者的1H-MRS表现,分析其脑内N-乙酰天门冬氨酸、肌酸和胆碱的代谢规律。设计:病例-对照观察。单位:南方医院神经内科。对象:病例组为2005-08/2006-08南方医院神经内科收治的,经临床和影像诊断的海洛因海绵状白质脑病3例(男2例,女1例),对照组为10例同龄健康志愿者。方法:使用Siemens Megnetom Vision Plus1.5T超导MR系统和标准头部线圈,应用化学位移成像法对所有受试者行1H-MRS检查。主要观察指标:观察额、顶和枕叶白质中N-乙酰天门冬氨酸、肌酸和胆碱的水平、代谢图以及它们之间的比例关系。结果:13例受试者均进入结果分析。①N-乙酰天门冬氨酸:病例1的额、顶和枕叶白质低于对照组(79.50±21.65,96.75±16.14,77.05±22.47;146.07±15.49,117.77±14.56,120.83±16.02;P<0.05,0.01),病例2、病例3的顶叶白质低于对照组(87.50±7.89,80.65±11.73,P<0.01)。②肌酸:病例组和对照组无显著性差异(P>0.05)。③胆碱:除病例1额叶白质以外,病例组中均低于对照(P<0.01)。④病例组N-乙酰天门冬氨酸/肌酸比值在各部位均较对照降低,而胆碱/肌酸降低更明显。⑤病灶处N-乙酰天门冬氨酸和肌酸在代谢图中均为低信号。⑥在病灶边缘区,胆碱/肌酸比值有明显反转现象。未见乳酸波。结论:1H-MRS发现海洛因海绵状白质脑病患者脑的物质代谢变化明显大于MRI病灶范围,病灶周围影像正常部位已经有代谢改变。

Characteristics of heroin spongiform leucoencephalopathy detected by hydrogen magnetic resonance spectroscopy

BACKGROUND:Point resolved spectroscopy (PRESS) or single-voxel spectroscopy (SVS) is always used in the previous researches of magnetic resonance spectroscopy (MRS) and its regions of interest are mainly located in focal zones which can be observed with magnetic resonance imaging (MRI); however, both of them cannot manifest the changes of focal marginal zone. Contrarily, hydrogen magnetic resonance spectroscopy (1H-MRS) can det ect the all regions of brain.OBJECTIVE: To observe the 1H-MRS manifestations of patients with heroin spongiform leucoencephalopathy (HSLE) so as to analyze metabolic regularities of N-acetyl aspartate (NAA), creatine (Cr) and bilineurine (Cho) in brain.DESIGN: Case-contrast observation.SETTING: Department of Neurology, Nanfang Hospital.PARTICIPANTS: Three HSLE patients including 2 males and 1 female who were diagnosed with clinical imaging were selected from the Department of Neurology, Nanfang Hospital from August 2005 to August 2006, and all of them were regarded as the case group. In addition, 10 healthy volunteers were regarded as the control group.METHODS: Siemens Megnetom Vision Plus 1.5T superconductive magnetic resonance (MR) system and standard head coil were used in this study, and then, all subjects were checked with 1H-MRS.MAIN OUTCOME MEASURES: Levels of NAA, Cr and Cho in white matter of frontal, parietal and occipital lobes, metabolic maps of them and ratios of NAA/Cr and Cho/Cr.RESULTS: All 13 subjects were involved in the final analysis. ① NAA level: The level of NAA in white matter of frontal,parietal and occipital lobes of case 1 was lower than that of the subjects in the control group (79.50±21.65, 96.75±16.14,77.05±22.47; 146.07±15.49, 117.77±14.56, 120.83±16.02; P ＜ 0.05, 0.01); meanwhile, white matter of parietal lobes of case 2 and case 3 was also lower than that of subjects in the control group (87.50±7.89, 80.65±11.73, P ＜ 0.01). ② Cr level: There were no significant differences of the Cr level of all subjects in both case group and control group (P＞ 0.05).③ Cho level: Except white matter of frontal lobes in case 1, the level of Cho was lower in the case group than that in the control group (P ＜ 0.01). ④ Ratio of NAA/Cr was lower in the case group than that in the control group, and the radio of Cho/Cr was decreased remarkably. ⑤ Metabolic maps of NAA and Cr manifested a low signal in focal site. ⑥ Ratio of Cho/Cr was obviously reversed in focal marginal zone, but wave of lactic acid was not observed at the same time.CONCLUSION: The area with abnormal metabolites in HSLE patients showed by 1H-MRS is obviously larger than the visible lesion area showed by MRI.There are abnormal metabolites in the adjacent area of HSLE lesions.