肌萎缩侧索硬化症病人大脑中央前回运动区磁共振波谱分析

目的 :1H MRS是否可确定ALS病人大脑皮质运动区神经元受损 ,是否适用于监测ALS病情。方法 :病例组包括 9例ALS病人。对照组包括 5例健康人 ,同时测定大脑皮质运动区的NAA、Cho、Cr。结果 :ALS病例组中NAA/Cr显著低于对照组 (P <0 0 5 ) ,Cho/Cr显著高于对照组 (P <0 0 1)。结论 :NAA/Cr下降和Cho/Cr升高 ,提示ALS病人大脑皮质运动区存在神经元破坏和鞘膜功能的异常     

Neurochemical alterations of the brain in bipolar disorder and their implications for pathophysiology: a systematic review of the in vivo proton magnetic resonance spectroscopy findings

OBJECTIVE: To perform systematic analysis of current proton magnetic resonance spectroscopy ((1)H MRS) findings in bipolar disorder (BD). METHOD: We grouped the (1)H MRS studies documenting data on the metabolites of N-acetylaspartate (NAA), Choline (Cho), myo-inositol (mI), Glutamate (Glu)/Glutamine (Gln) and Creatine (Cr) separately, for each of the euthymic, manic, depressed adult and child/adolescent bipolar patients. RESULTS: For NAA resonance, 22 studies involving 328 adult bipolar and 349 control subjects were identified. NAA levels were lower in euthymic bipolar patients in the frontal lobe structures and hippocampus. Lithium seems to have an increasing effect on NAA in those brain regions. Available data in children indicates lower NAA levels in euthymic bipolar patients in dorsolateral prefrontal cortex (DLPFC) and cerebellar vermis. Existing data over 25 studies on 366 adult bipolar and 393 control subjects, although inconsistent, may suggest higher Cho/Cr ratios in the basal ganglia (BG) of euthymic bipolar patients. The metabolite mI seems to be increased both in euthymic and manic bipolar children, while most of the available data does not support such alteration in adults. Glu/Gln levels in adult bipolar patients were higher in all mood states compared to controls. Limited data in children supports such an alteration only in the euthymic state. CONCLUSION: The studies reviewed in this paper suggest regional abnormalities of NAA, Cho and Glu/Gln in BD, with the DLPFC, prefrontal and anterior cingulate cortices, hippocampus, and BG being specifically implicated. Systematic analysis of (1)H MRS findings so far helps to define future strategies in this field for delineation of actual neurochemical framework in BD.     

Variation of the choline signal intensity in the dorsolateral prefrontal cortex of rats exposed to the forced swimming test as detected by in vivo 1H MR spectroscopy

BACKGROUND: (1)H magnetic resonance spectroscopy (MRS) has documented an increased Cho/Cr ratio in the dorsolateral prefrontal cortex (DLPFC) in major depressive disorder (MDD). The aim of this study was to investigate neurochemical alterations in the left DLPFC, considered a main area of pathogenesis in depression, using rats exposed to the forced swimming test (FST). MATERIALS AND METHODS: Twenty-four male rats were used for the MRI and in vivo(1)H MRS studies. Rats exposed to the FST to induce a depressed mental status. Using in vivo(1)H MRS, the metabolite ratios of the rats with a depressed mental status and the controls, were measured and the values of the two groups were compared. RESULTS: The Cho/Cr and Cho/NAA ratios in the DLPFC of the rats with a depressed mental status were significantly higher than that in the controls. CONCLUSIONS: The present study demonstrates a significantly increased Cho/Cr ratio in the DLPFC of rats with depression compared with controls. This result may suggest an accelerated turnover of membrane without neuronal loss is occurring in the DLPFC of the rats with depression.     

1H Magnetic resonance spectroscopy study of dorsolateral prefrontal cortex in unipolar mood disorder patients

Neuroimaging and postmortem studies have suggested the involvement of the dorsolateral prefrontal cortex (DLPFC) in the pathophysioloy of unipolar disorder. We examined with in vivo 1H magnetic resonance spectroscopy (MRS) the levels of specific metabolites in the DLPFC of adult unipolar patients and the role of illness chronicity on DLPFC abnormalities. Nineteen unmedicated unipolar mood disorder patients and 19 age- and gender-matched healthy controls underwent a short echo-time 1H MRS examination localized to an 8-cm3 single voxel placed in the left DLPFC. There were no significant differences in metabolite levels, including N-acetylaspartate (NAA), phosphocreatine plus creatine (PCr+Cr) and choline-containing-compounds (GPC+PC), between the two groups. However, NAA/PCr+Cr ratios were significantly lower in the chronic than in the less chronically ill patients and healthy controls. The low levels of NAA/PCr+Cr ratios in the left DLPFC of unipolar patients who had been more chronically ill suggest a potential role for illness chronicity in neuronal abnormalities in the DLPFC in unipolar disorder. This could possibly be accounted for by neurodegenerative processes arising with the progression of the illness. Future 1H MRS investigations should longitudinally examine the role of illness chronicity on DLPFC abnormalities and their relationship with the symptoms of unipolar disorder.     

Proton magnetic resonance spectroscopy of the motor cortex in 70 patients with amyotrophic lateral sclerosis

OBJECTIVE: To evaluate proton magnetic resonance spectroscopy for detection and monitoring of upper motoneuron degeneration in patients with amyotrophic lateral sclerosis. METHODS: Seventy patients with amyotrophic lateral sclerosis according to the El Escorial criteria were compared with 48 healthy control subjects. Single-volume proton magnetic resonance spectroscopy (echo time, 272 milliseconds; repetition time, 2000 milliseconds) was performed in both motor cortices for detection of N-acetylaspartate (NAA), phosphocreatine + creatine ([P]Cr), and choline-containing compounds (Cho) to calculate the metabolite ratios NAA/Cho, NAA/(P)Cr, and Cho/(P)Cr. In addition, absolute metabolite concentrations of NAA, (P)Cr, and Cho were obtained in 30 patients and 15 controls with the unsuppressed water signal used as an internal reference. RESULTS: Absolute concentrations of NAA (P<.001) and (P)Cr (P<.05) were reduced in motor cortices of patients, whereas Cho concentrations remained unchanged. The NAA/Cho and NAA/(P)Cr ratios were reduced in all El Escorial subgroups (P<.001). The Cho/(P)Cr ratio was elevated in patients with definite amyotrophic lateral sclerosis (P<.05). Metabolite ratio changes corresponded to the lateralization of clinical symptoms and were weakly correlated with disease duration and disease severity. In follow-up observations of 16 patients during a mean (+/-SD) of 12.1 +/- 8.7 months, NAA/Cho dropped by 9.1% (P<.01), and Cho/(P)Cr increased by 7.0% (P<.01). Changes of metabolite ratios were significantly correlated with progression of disease severity. CONCLUSIONS: Measurement of NAA concentrations and NAA/Cho ratios appear to be most suitable for detection of motor cortex degeneration by single-volume proton magnetic resonance spectroscopy. Reduced NAA/Cho ratios correspond to aspects of the clinical presentation and reflect disease progression in follow-up measurements.     

The human motor cortex after incomplete spinal cord injury: an investigation using proton magnetic resonance spectroscopy

OBJECTIVES—(1) A biochemical investigation of themotor cortex in patients with incomplete spinal cord injury and normalcontrol subjects using proton magnetic resonance spectroscopy (MRS).(2) To relate any altered biochemistry with the physiological changesin corticospinal function seen after spinal cord injury.
METHODS—a group of six patients with incompletespinal cord injury who showed good recovery of motor function wereselected. The patients were compared with five healthy controlsubjects. Electromyographic (EMG) responses of thenar muscles totranscranial magnetic stimulation (TMS) of the motor cortex showed thatinhibition of cortical output was weaker in the patients than thecontrols. Proton MRS data were collected from a plane at the level ofthe centrum semiovale. Two 4.5 cm³ voxels in the motorcortex and a third voxel in the ipsilateral occipital cortex wereexamined in the patients and control subjects.
RESULTS—The mean level ofN-acetylaspartate (NAA), expressed relative to thecreatine (Cr) peak (NAA/Cr), was significantly increased in the motorcortex of the patients compared with their ipsilateral occipital cortexor either cortical area in the controls. No differences betweenpatients and controls were seen for any of the other metabolite peaks(choline (Cho), glutamate/glutamine (Glx) or the aspartate component ofNAA (Asp^NAA)) relative to Cr. Choline relative to Cr(Cho/Cr) was higher in the motor cortex of the control subjects than intheir ipsilateral occipital cortex. This difference was not present inthe patients.
CONCLUSIONS—Raised NAA/Cr in the motorcortex of the patients probably results from increased NAA rather thana decrease in the more stable Cr. The possible relevance of a raisedNAA/Cr ratio is discussed, particularly with regard to the changedcorticospinal physiology and the functional recovery seen in the patients.

     

Brain metabolites in definite amyotrophic lateral sclerosis

Abstract Biomarkers beyond clinical assessment are needed in patients who suffer from amyotrophic lateral sclerosis (ALS). Here, single-voxel proton magnetic resonance spectroscopy (¹H MRS) of the gray matter of the motor cortex and the white matter including the pyramidal tracts was used to investigate concentrations of N-acetylaspartate (NAA), creatine (Cr), choline (Cho), myoinositol, glutamate, and glutamine in patients with definite ALS in a longitudinal design (three measurements at study inclusion, after 3 and 6 months). A volume-corrected analysis of gray and white matter fractions within the volumes of interest (VOI) was performed for the identification of the absolute metabolite concentrations. The patient group showed a significant decline of the compound NAA over time in the motor cortex areas both of the clinically more and less affected hemisphere between first measurement and month 6 and for the less affected side additionally between first measurement and month 3. For the NAA/(Cr + Cho) ratio, significant decline in the less affected hemisphere was observed from the first measurement to month 3 and to month 6 as well as from month 3 to month 6. In contrast, neither NAA nor the NAA/(Cr + Cho) ratios in the white matter areas showed any significant alterations. All other compounds showed no significant changes over time. In summary, the longitudinal changes of cortical metabolite concentrations in the course of ALS could be assessed by optimized ¹H MRS techniques at group level, so that ¹H MRS parameters, in particular volume-corrected values of NAA in the clinically less affected hemisphere, seem to have the potential to serve as a surrogate marker for monitoring ALS disease progression.     

Low levels of N-acetyl aspartate in the left dorsolateral prefrontal cortex of pediatric bipolar patients

BACKGROUND: Increasing evidence suggests abnormalities in the structure, function, and neurochemistry of the frontal cortex in pediatric bipolar (BP) patients. We conducted a single-voxel proton magnetic resonance spectroscopy ((1)H MRS) of the left dorsolateral prefrontal cortex (DLPFC) of pediatric BP patients, expecting lower N-acetyl-aspartate (NAA) levels within that brain region compared to healthy comparison subjects. METHODS: We studied 35 pediatric BP (23 BP type I, 12 BP type II; mean age +/- SD = 13.2 +/- 2.9 years; 18 females) and 36 healthy controls (mean age +/- SD = 13.7 +/- 2.6 years, 17 females). A short echo time, single-voxel (1)H spectroscopy approach point-resolved spectroscopy (PRESS) sequence, measurements of metabolites was performed on a 1.5T Philips MR system. RESULTS: BP subjects had significantly lower NAA levels in the left DLPFC compared to healthy controls (F = 4.21, df = 1, 68, p = 0.04). There was not a significant difference between groups for phosphocreatine + creatine (PCr+Cr), glycerolphosphocholine + phosphocholine (GPC + PC), myo-inositol (mI), or glutamate. Further analyses revealed a significant reduction of NAA in our early puberty group compared to controls (Mann-Whitney U-test statistic = 52.00, p = 0.014), but not for BP versus controls in other pubertal groups. CONCLUSIONS: BP subjects have lower NAA levels in the left DLPFC compared to healthy subjects, suggesting neuronal dysfunction in this region.     

Metabolic changes in 37 newly diagnosed Wilson's disease patients assessed by magnetic resonance spectroscopy

Wilson's Disease (WD) is a rare autosomal recessive disorder. The literature about proton MR spectroscopy (MRS) in WD is based mostly on data derived from patients undergoing treatment. The aim of this study was to identify brain metabolic changes in newly diagnosed WD patients using MRS to elucidate the pathomechanism of the cerebral pathology of WD. The globus pallidus and thalamus of 37 patients with WD were examined bilaterally with MRS. The calculations were performed for: myoinositol (mI), choline (Cho), creatine (Cr), N-acetyl-aspartate (NAA), lipid (Lip), glutamine, and glutamate (Glx). In all WD patients a significantly decreased mI/Cr and NAA/Cr ratio levels and an increased Lip/Cr ratio in the pallidum were observed. Analysis revealed a significantly increased Glx/Cr and Lip/Cr ratio in the thalamus. In the pallidum of neurologically impaired patients, Cho/Cr, Glx/Cr and Lip/Cr ratios were higher than in control subjects, and the NAA/Cr was significantly lower. In hepatic patients, the mI/Cr, Cho/Cr and NAA/Cr ratio levels were lower than in controls. The Cho/Cr and Lip/Cr ratios were higher in the thalami of neurologically impaired patients, and Lip/Cr ratios were higher than controls' in hepatic patients. Both findings were statistically significant. Compared to the thalamus, the basal ganglia are more sensitive to ongoing degenerative changes and portal-systemic encephalopathy in WD. The NAA/Cr reduction in hepatic and neurologically impaired patients could indicate that neurodegeneration is associated with all presentations of WD. In hepatic patients a mI and Cho decrease and in neurological Glx increase can be caused by porto-systemic shunting.     

Proton magnetic resonance spectroscopy (H-MRS) of the thalamus in schizophrenia

This study applied ¹H-MRS in the thalamus of schizophrenic patients and healthy subjects.There were no differences in the metabolite ratios (NAA/Cr, Cho/Cr or mI/Cr) between the two groups. Relationships were noted between NAA/Cr and age in patients with a trend toward this correlation in controls, suggesting an effect of age on the metabolism of the thalamus.     

磁共振波谱分析对轻微型肝性脑病患者的诊断价值

目的研究磁共振波谱分析(MRS)对轻微型肝性脑病(MHE)患者的诊断价值。方法应用3.0MR机对26例MHE患者进行扣带回和额叶的单体素点分辨自旋回波波谱序列扫描。计算N-乙酰天门冬氨酸(NAA)、肌酐(Cr)、胆碱(Cho)、肌醇(mI)和谷氨酰胺复合物(Glx)的峰下面积,计算NAA/Cr、Cho/Cr、mI/Cr、Glx/Cr的值,并与正常对照组比较。结果与正常对照组相比,MHE组扣带回和额叶的Cho/Cr、mI/Cr显著降低(P<0.01～0.001),Glx/Cr值显著升高(均P<0.005),NAA/Cr值差异无统计学意义(均P>0.05)。结论MHE患者MRS检查显示扣带回和额叶Cho、mI水平降低,Glx水平升高,MRS对MHE的诊断有显著价值。     

Early detection and longitudinal changes in amyotrophic lateral sclerosis by (1)H MRSI

OBJECTIVE: To determine 1) the reproducibility of metabolite measurements by (1)H MRS in the motor cortex; 2) the extent to which (1)H MRS imaging (MRSI) detects abnormal concentrations of N-acetylaspartate (NAA)-, choline (Cho)-, and creatine (Cre)-containing compounds in early stages of ALS; and 3) the metabolite changes over time in ALS. METHODS: Sixteen patients with definite or probable ALS, 12 with possible or suspected ALS, and 12 healthy controls underwent structural MRI and multislice (1)H MRSI. (1)H MRSI data were coregistered with tissue-segmented MRI data to obtain concentrations of NAA, Cre, and Cho in the left and right motor cortex and in gray matter and white matter of nonmotor regions in the brain. RESULTS: The interclass correlation coefficient of NAA was 0.53 in the motor cortex tissue and 0.83 in nonmotor cortex tissue. When cross-sectional data for patients were compared with those for controls, the NAA/(Cre + Cho) ratio in the motor cortex region was significantly reduced, primarily due to increases in Cre and Cho and a decrease in NAA concentrations. A similar, although not significant, trend of increased Cho and Cre and reduced NAA levels was also observed for patients with possible or suspected ALS. Furthermore, in longitudinal studies, decreases in NAA, Cre, and Cho concentrations were detected in motor cortex but not in nonmotor regions in ALS. CONCLUSION: Metabolite changes measured by (1)H MRSI may provide a surrogate marker of ALS that can aid detection of early disease and monitor progression and treatment response.     

Effect of Creatine Supplementation on Metabolite Levels in ALS Motor Cortices

Mitochondrial pathology is an early observation in motor neurons and skeletal muscle of patients with amyotrophic lateral sclerosis (ALS). To clarify the relevance of this finding, we determined the effects of a 1-month oral administration of creatine on (1)H NMR-visible metabolites in the motor cortices of 15 controls and 15 patients with sporadic ALS, most of whom had mitochondrial pathology in skeletal muscle. In the motor cortex of the ALS group the N-acetylaspartate (NAA)/creatine (Cr(t)) metabolite ratio was lower than in our control group, indicating NAA loss. Upon creatine supplementation we observed in the controls a decline in the NAA/Cr(t), NAA/choline (Cho), glutamate + glutamine (Glx)/Cr(t), and Glx/Cho metabolite ratios. In contrast, in the ALS patient group the NAA/Cr(t) and the NAA/Cho metabolite ratios remained unchanged, while the Glx/Cr(t) and Glx/Cho metabolite ratios decreased. These data are compatible with the interpretation that creatine supplementation causes an increase in the diminished NAA levels in ALS motor cortex as well as an increase of choline levels in both ALS and control motor cortices. Because NAA is synthesized by mitochondria in an energy-dependent manner and the NAA/Cho metabolite ratios in the ALS motor cortices were found to be correlated to the degree of mitochondrial pathology in ALS skeletal muscle, our results can be explained by a deficiency of enzymes of mitochondrial respiratory chain in the ALS motor cortex which might affect motor neuron survival.     

Proton magnetic resonance spectroscopy (1H-MRS) of motor cortex and basal ganglia in de novo Parkinson's disease patients

Proton MR spectroscopy (¹H-MRS) has been previously performed in Parkinson's disease (PD) and parkinsonian syndromes to evaluate in vivo concentrations of basal ganglia and cerebral cortex metabolites such as N-acetylaspartate (NAA), choline (Cho), and creatine (Cr). However, this technique has never been used to evaluate motor cortex in untreated PD patients. In this study, single-voxel ¹-H-MRS of basal ganglia and motor cortex was carried out in 10 de novo patients with PD and 10 age-matched healthy controls. A significant reduction in the NAA/Cr ratio was observed in the motor cortex of PD patients compared with controls (p<0.01). Basal ganglia spectra did not allow any evaluation due to the presence of artefacts related to inorganic paramagnetic substances. The motor cortex reduction of the NAA/Cr ratio in de novo PD patients may reflect an altered neuronal functioning due to a loss of thalamocortical excitatory inputs and may represent an in vivo marker for the diagnosis of PD.     

A proton magnetic resonance spectroscopy study in schizoaffective disorder: Comparison of bipolar disorder and schziophrenia

The aim of this study was to compare schizoaffective disorder, bipolar disorder and schizophrenia based on (1)H-MRS metabolite values in dorsolateral prefrontal cortex and executive functions. The subjects comprised 15 patients with bipolar disorder type I (BD), 15 with schizophrenia (SCH), 15 with schizoaffective disorder (SAD) and 15 healthy controls. We performed proton magnetic resonance spectroscopy ((1)H-MRS) of the dorsolateral prefrontal cortex (DLPFC) bilaterally. Levels of N-acetyl aspartate (NAA), choline-containing compounds (Cho) and creatine-containing compounds (Cr) were measured in the DLPFC using (1)H-MRS. We administered the Wisconsin Card Sorting Test (WCST) and the Stroop Test (ST) to evaluate executive functions. The SAD, BD and SCH patients had lower levels of NAA than the control group. The SAD and BD patients had low levels of Cho compared to the control group. The left DLPFC Cr levels in all of the patient groups and the right DLPFC Cr levels in the BD and SAD groups were lower than in the control group. The levels of NAA Cho and Cr were not related to executive functions and attention performance. Cr level were related to attention processes, only in SCH. Our results indicate that NAA levels are reduced in schizoaffective disorder, bipolar disorder and schizophrenia, but the reduction in the levels of NAA is not a distinctive feature among these three illnesses. Schizoaffective and bipolar disorders have similar features related to the levels of compounds containing Cho and Cr. This similarity may be related to these illnesses both having an affective basis.     

Influences of dopaminergic treatment on motor cortex in Parkinson disease: a MRI/MRS study.

The objective of this study was to investigate neurochemical and metabolic changes in the motor cortex in a group of de novo Parkinson's disease (PD) patients before and after 6 mo treatment with the dopamine agonist pergolide. Proton magnetic resonance spectroscopy (1H-MRS) has been used to study striatal and cortical metabolism in PD and other parkinsonisms. So far, no studies evaluating possible brain metabolic changes in PD patients before and after dopaminergic therapy have been reported. De novo PD patients (11) and controls (11) underwent clinical evaluation (UPDRS-III motor evaluation) and a first single-voxel 1H-MRS of the motor cortex. 1H-MRS studies were performed using the PROBE-SV System implemented on a 1.5 Tesla Scanner (GE Medical System, Milwaukee, WI). Pergolide was administered up to a dose of 1 mg t.i.d. After 6 mo follow-up, all patients were clinically evaluated and a second single-voxel 1H-MRS was performed. Lower values of Cho/Cr and NAA/Cr ratios were observed in the motor cortex of PD patients compared with controls (P < 0.02 and P < 0.01, respectively). After 6 mo therapy with pergolide (1 mg t.i.d), PD patients showed an improvement in motor performances (P < 0.05) and an increase in Cho/Cr ratios in the motor cortex at the second 1H-MRS evaluation (P < 0.05) was reported. In conclusion, cortical NAA/Cr and Cho/Cr ratios may be impaired in de novo PD. Dopaminergic therapy capable of improving motor function may restore the Cho/Cr ratio in the motor cortex.     

MR spectroscopy in monitoring the treatment of Wilson's disease patients

The aim of this study was to determine the effectiveness of brain proton magnetic resonance spectroscopy (¹H‐MRS) for monitoring therapy in Wilson's disease (WD) patients. Voxels were located in the globus pallidus (right, left). We followed 17 newly diagnosed WD cases for 1‐year period. During this observation period, 6 neurological and 9 hepatic patients improved, while 2 neurological patients deteriorated. The pretreatment ¹H‐MRS analysis showed a statistically significant lower level of mI/Cr, NAA/Cr, and higher Lip/Cr in all WD patients with improvement compared with controls. In patients with hepatic signs, a statistically significant increase of mI/Cr and Glx/Cr was observed in the second (1 year posttreatment) ¹H‐MRS. In patients with neurological improvement after treatment in the follow‐up ¹H‐MRS, a statistically significant increase of NAA/Cr was noted. During neurological deterioration, a decrease of Glx/Cr and NAA/Cr was seen, in contrast to another neurologically impaired patient with liver failure exacerbation, where a decrease of mI/Cr and increase of Glx/Cr was observed. The alternations of NAA/Cr ratio in neurologically impaired patients and mI/Cr and Glx/Cr in patients with liver failure could be a sensitive marker of the clinical recovery and deterioration in those WD patients. ¹H‐MRS is a technique that can be used for accurate monitoring of treatment efficacy in WD patients. © 2008 Movement Disorder Society     

Cognitive impairment: classification by 1H magnetic resonance spectroscopy.

1H magnetic resonance spectroscopy (MRS) allows accurate and non-invasive in vivo metabolic study, and is a useful tool for the diagnosis of different forms of dementias. Cognitive impairment pathologies have been almost exclusively studied with MRS by comparison with healthy without a global comparison amongst Alzheimer disease (AD), vascular dementia, mild cognitive impairment (MCI) and major depression patients with cognitive impairment. Whereas decrease of N-acetylaspartate (NAA) and increase myo-Inositol (mI) at different brain locations by 1H MRS are common features of AD, Choline (Cho) alterations have been inconclusive. In our study, 64 patients with cognitive impairment were evaluated by 1H MRS using two echo times (31 and 136 ms). There were statistical differences between dementia (AD and vascular dementia) and non-dementia (MCI and depression) spectra at posterior cingulate gyrus. Cho/Cr, mI/Cr and NAA/Cr have been valuables for the differentiation amongst the different cognitive impairment entities. NAA/mI provides the best area under the ROC curve with the highest sensitivity (82.5%) and specificity (72.7%) in diagnosing AD. NAA/mI and mI/Cr ratios differed amongst the four cognitive impairment degenerative pathologies. Metabolic MRS differences found amongst patients with cognitive impairment entities can be useful to differentiate between AD, vascular dementia, MCI and depression.     

3T磁共振波谱分析在轻微型肝性脑病诊断中的应用

目的研究3T场强磁共振MRS对轻微型肝性脑病（MHE）患者的诊断价值。方法对33例MHE患者和46例无轻微型肝性脑病的肝硬化患者采用单体素点分辨自旋回波波谱序列进行扣带回和右侧前额叶的MRS扫描。计算N-乙酰天门冬氨酸（NAA）、肌酐（Cr）、胆碱（Cho）、肌醇（MI）和谷氨酰胺复合物（Glx）的峰下面积,计算NAA／Cr、Cho／Cr、MI／Cr、Glx／Cr,并与30例健康体检者（正常对照组）比较。33例MHE患者在MRS检查前后1周内进行了静脉血氨水平测定。结果与正常对照组相比,MHE患者扣带回和右侧前额叶的Cho／Cr、MI／Cr显著降低（P值分别〈0．01和〈0．001）,Glx／Cr比值显著升高（P〈0．005）。与无MHE的肝硬化患者间Glx／Cr与Cho／Cr有显著性差异（P〈0．01,P〈0．005）,无MHE的肝硬化患者与正常对照组比较MI／Cr有显著性差异（P〈0．001）。扣带回与右侧额叶的Glx／Cr比值与血氨浓度呈正相关,Cho／Cr和MI／Cr的比值与血氨浓度呈负相关。结论3T场强磁共振MRS检查显示MHE患者扣带回和右侧前额叶Cho、MI水平降低,Glx水平升高;扣带回与右侧额叶的MRS指标与血氨之间存在相关关系,3T场强磁共振MRS对MHE的诊断有显著价值;扣带回与右侧前额叶可作为检测肝硬化患者脑改变的敏感部位。     

Application of proton magnetic resonance spectroscopy on substantia nigra metabolites in Parkinson’s disease

This study investigates changes in substantia nigra metabolites in Parkinson’s disease (PD) using proton magnetic resonance spectroscopy (¹H- MRS). Thirty patients with asymmetric PD and 20 normal controls were included in this study. Substantia nigra metabolites were detected in all subjects using 3D-multimer ¹H-MRS with a 3.0 T MRI scanner. The relative ratios of NAA/Cr, NAA/Cho, NAA/(Cho + Cr) in the substantia nigra were compared between two sides of asymmetric PD patients as well as between PD patients and controls. Significant differences in NAA/Cr, NAA/Cho, NAA/(Cho + Cr) were observed between PD patients and healthy controls (P?<?0.05) as well as between the ipsilateral and contralateral of affected extremity in PD patients (P?<?0.05). Significant differences in NAA/Cr, NAA/Cho, NAA/(Cho + Cr) were also observed between patients with mild and severe PD. Thus, we found that ¹H-MRS can be used to detect substantia nigra metabolites in PD patients, which may be useful for early diagnosis and evaluation of PD.