Clinical Utility of Information of Metabolite Diffusion, Concentration and Relaxation Time Evaluated by Multiple Parametric Analysis

我们用质子磁共振波谱方法测量了脑内的代谢物，并评估了代谢物浓度、代谢物扩散和松弛时间。用多元协方差分析(MANCOVA)和因子分析对各参数进行估计，并讨论各代谢物参数的临床应用。1)正常脑组织代谢物浓度的增龄性变化：最大年龄组(60岁)的NAA浓度在两个测量部分之间有显著差异(后检验：P&lt；0.01)。Cr和Cho似乎不随年龄增长而变化。统计分析结果采用单因素方差分析和方差分析。这表明豆状核上的NAA浓度在年龄上有显著差异，而额叶上的NAA浓度没有统计学差异。两个部位五个年龄段的铬浓度无显著差异，晶状体上的CHO浓度有m…五组间差异有统计学意义的概率较低。用单因素方差分析比较各代谢物与脑区衰老变化的相关性。NAA的增龄变化与脑区之间存在显著的交互作用(P&lt；0.01)，从而表明NAA浓度随年龄的变化随脑区的不同而不同。2)自闭症患者脑区代谢的差异自闭症患者和对照组的松弛时间如表所示，两组间无显著差异(P&gt；0.1)，典型的颞叶磁共振频谱显示患者与对照组略有差异。患者颞叶NAA浓度也有升高趋势，但各年龄组与正常对照组比较差异有统计学意义。经多元统计比较，自闭症患者脑内NAA浓度的增龄性变化因脑区不同而不同，其中颞叶、顶叶NAA浓度的增龄性变化与同一地区的正常对照组有显著差异(P&lt；0.05)。而其他脑区的NAA变化在患者组与对照组之间无统计学差异。由于NAA浓度可以作为神经元标记物，这一结果可能提示孤独症患者颞叶和顶叶神经元密度低或神经元功能障碍，并可能提示自闭症患者语言障碍的原因。我们认为，NAA浓度和扩散状态的变化取决于正常年龄，病理变化即使在解剖影像没有异常发现的情况下也会超过正常年龄的变化。多参数分析将提供正常衰老与病理改变的临床判断和阈值。较少

We measured intra-cerebral metabolites by proton MR spectroscopic method using a clinical MR instrument and evaluated metabolite concentration, metabolite diffusion and relaxation time. Each parameter was estimated by multi-parametrci analysis including multiple analysis of covarience (MANCOVA) and factor analysis, and clinical utility of each metabolite parameter was discussed.1) Aging change of metabolite concentration in the normal brain :The NAA concentration in the oldest age group (60s- year) showed marked difference between two measurement portions(post-hoc tests : P<0.01). Cr and Cho were seemed not to change with aging. The result of statistical analysis was conducted using ANOVA and ANCOVA. This revealed the remarkable aging difference of NAA concentration on the lenticula but no statistical difference of NAA on the frontal lobe. The Cr concentration showed no significant difference in the five age groups on the both locations, and the Cho concentration on the lenticula had m … More edium significant probability of statistical difference in the five groups. MANCOVA was conducted to compare the correlation in aging change of each metabolite and the cerebral regions. A significant interaction(P<0.01) between aging change of NAA and the cerebral regions, thereby indicating that the change in NAA concentration with age was different deponding on the cerebral region.2) Metabolic difference of cerebral region with autistic patientsThe relaxation times of patients and controls were shown in Table and no significant difference was found between two groups (P>0.1) , The typical MR spectra of temporal lobe between patients and controls showed slight difference. The increasing tendency of NAA concentration was found even in the temporal lobe of patients, but is was significant different from that of normal controls depending on each age. By multiple statistical comparison, the aging change of NAA concentration of autistic patients were different depending on the cerebral region, and those in the temporal lobe and parietal lobe were significant different (P<0.05) from that of normal controls in the same region. However the NAA changes in other cerebral regions did not show any statistical difference between patients and controls. Because NAA concentration could be a neuronal marker, this result may suggest low neuronal density or neuronal dysfunction in the temporal lobe and parietal lobe of autism and might indicate the cause of language disorder in autism.We considered that NAA concentration and diffusion status changed depending on normal aging and pathological changed would exceed the normal aging variation even when anatomical imaging shows no abnormal finding. The multiple parmaetric analysis will offer the clinical judgement and threshold between normal aging and pathological changes. Less