脑干胶质瘤磁共振波谱分析

目的探讨磁共振波谱(Magnetic resonance spectroscopy,MRS)在脑干胶质瘤诊断中的意义。方法回顾性分析10例脑干胶质瘤的临床资料,肿瘤位于中脑1例,中脑脑桥1例,脑桥7例,延髓1例。均行MRS检查,对肿瘤区、肿瘤边缘区和正常对照区进行对照研究。结果MRS均显示肿瘤区N-乙酰天门冬氨酸(N-acetylaspartate,NAA)峰值下降,胆碱(Choline,Cho)峰上升。与肿瘤边缘区和正常对照区比较,肿瘤区NAA/Cr明显减低,Cho/Cr和Cho/NAA明显升高。星形细胞瘤4例,间变性星形细胞瘤1例,胶质母细胞瘤2例;另3例根据临床特点和影像学表现诊断为脑干胶质瘤。结论MRS可检测到脑干胶质瘤的代谢改变,具有无创、敏感、诊断准确的特点。     

颅脑肿瘤质子磁共振波谱研究

目的 :评价质子磁共振波谱 (1HMRS)在颅脑肿瘤诊断中的应用价值。方法 :分析 68例颅脑肿瘤1HMRS表现。结果 :治疗前1HMRS显示 :所有肿瘤NAA/Cho、NAA/Cr下降或消失 ,Cho/Cr明显升高。 2 6例行手术后放疗 ,其中 7例出现放射性坏死 ,肿瘤残留或复发 6例。 19例仅行放疗或γ刀治疗。1HMRS显示 ,治疗后NAA/Cho、NAA/Cr比值均较治疗前升高 ,Cho/Cr比值下降。结论 :1HMRS有助于提高颅脑肿瘤治疗前诊断和鉴别诊断的精确性 ;术前分期、分级 ;术后随访 ,鉴别肿瘤残留、复发或放射性坏死     

质子磁共振波谱在胶质瘤诊断中的应用

目的 研究质子磁共振波谱（1H Magnetic Resonance Spectroscopy,1HMRS）在胶质瘤诊断及分级中的应用。方法搜集行1HMRS检查并经病理证实的36例胶质瘤患者,其中A组星形胶质细胞瘤Ⅰ～Ⅱ级21例,B组星形胶质细胞瘤Ⅲ～Ⅳ级和多形性胶质母细胞瘤15例。对侧部位的结果作内对照组。观察氮乙酰门氡氨酸（N—acetylaspartate,NAA）、胆碱（choline,Cho）、肌酸（creatine,Cr）、肌醇（Ins）的共振峰及比值。结果A组同对照组间NAA／Cr、NAA／Cho、Cho／Cr差异有统计意义（P〈0．05）。B组同对照组间NAA／Cr、NAA／Cho、Cho／Cr差异有统计意义（P％0．05）。A组与B组间NAA／Cr和NAA／Cho差异有统计意义（P〈0．05）。结论 1HMRS可提高对胶质瘤诊断和分级的准确性。     

磁共振波谱在脑内肿瘤鉴别诊断中的价值研究

目的探讨磁共振波谱（MRS）在脑内肿瘤鉴别诊断中的应用价值。方法收集75例颅内占位性病变患者术前行磁共振波谱检查的临床资料,对其经临床手术、病理诊断证实的最终结果进行分析。结果MRS提示肿瘤72例,病理证实70例;脑脓肿1例,病理证实1例;MRS提示囊性占位2例。胶质瘤的MRS表现为NAA明显降低或降低,Cho升高,肿瘤周围脑组织呈类似改变;脑膜瘤的MRS表现为NAA消失或降低,Cho升高或明显升高,Cr信号降低,可见到Ala峰,肿瘤周围脑组织相对正常;转移瘤的MRS表现为Cho明显升高,NAA明显降低,而瘤旁脑组织MRS波形基本正常;淋巴瘤的MRS表现为肿瘤区域NAA降低,Cho升高或明显升高,并可见到Lip峰。结论MRS作为无创性的检测手段,对脑内肿瘤的鉴别诊断有较大的参考价值。     

磁共振波谱分析应用于脑胶质瘤分级的研究

目的探讨脑胶质瘤患者应用磁共振波谱分析疾病分级的效果。方法对我院61例脑胶质瘤患者进行1 HMRS结合MRI诊断,并对不同级别的脑胶质瘤相关指标进行对比分析。结果脑胶质瘤患者Cr轻度下降,NAA呈显著性下降,Cho呈显著增高。低、高级别脑胶质瘤的肿瘤组织与对侧正常脑组织的NAA、Cho值有显著性差异(P0.05);低级别和高级别脑胶质瘤的肿瘤组织NAA、Cr值有显著性差异(P0.05)。NAA/Cho和NAA/Cr值反映肿瘤级别较稳定;NAA/Cr、NAA/Cho值呈负相关,Cho/Cr值呈正相关。结论临床上采用1 H-MRS结合MRI对脑胶质瘤患者进行诊断准确性高,尤其对胶质瘤代谢特性与肿瘤生长的潜能情况,具有较好的准确性,值得临床推广。     

磁共振质子波谱分析对颞叶癫(癇)定侧的研究

目的探讨在磁共振质子波谱分析(1HMRS)对颞叶癫疒间的定侧作用及其影响因素。方法用1.5T场强的MR成像系统1HMRS,对40例不同病程的颞叶癫疒间患者和20名正常对照者分别进行双颞叶内侧N乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)浓度测定,根据颞叶癫疒间患者两侧NAA/(Cho Cr)值进行定侧。结果NAA/(Cho Cr)值正常对照组为0.58±0.09,癫疒间组病灶侧为0.45±0.12,病灶对侧为0.51±0.10,癫疒间组两侧显著小于正常对照组(均P<0.05);24例患者1HMRS癫疒间灶定侧与EEG一致,符合率63%;病灶侧内、中、外各亚区NAA/(Cho Cr)值较正常对照组低,差异有显著性(均P<0.05);病灶侧NAA/(Cho Cr)值下降程度与单或双侧NAA/(Cho Cr)值下降及发作频率无关(P>0.05);双侧NAA/(Cho Cr)值异常者两侧EEG异常率高于单侧异常者(P<0.05);病灶侧NAA/(Cho Cr)值与病程呈负相关(r=-0.361,P<0.05)。结论癫疒间患者脑代谢异常弥散;1HMRS在颞叶癫疒间有定侧作用;NAA/(Cho Cr)值与病程呈负相关。     

MRS及DWI在脑胶质瘤中的应用价值

目的 探讨磁共振扩散加权成像（DWI）和1H-磁共振波谱（1H -MRS）在诊断脑胶质瘤及评价其分级中的作用.方法 选取80例脑胶质瘤患者进行DWI及MRS检查,通过测定脑肿瘤实质部分、对照正常侧的ADC值及比值（rADC）、N-乙酰天门冬氨酸（NAA）、胆碱（Cho）、肌酸（cr）水平及其比值,结合患者术后病理学检查结果,分析磁共振扩散加权成像（DWI）表观弥散系数（ADC）值和1H -磁共振波谱（1H -MRS）在诊断脑胶质瘤及其分级中的作用.结果 （1）高级别组患者ADC值与rADC值均显著低于低级别组,相关分析发现ADC值与rADC值与肿瘤级别呈负相关;（2）与低级别组相比,高级别组患者NAA/Cho、NAA/Cr显著降低,Cho/Cr值显著升高,差异有统计学意义（P＜0.05）.相关分析显示NAA/Cho、NAA/Cr与肿瘤级别呈负相关,Cho/Cr与肿瘤级别呈正相关.结论 通过检测rADC值、NAA/Cho、NAA/Cr、Cho/Cr的变化,可以评价低级别及高级别的脑胶质瘤,为术前分级提供重要的指导.     

颅内间变型星形细胞瘤影像表现回顾性分析

目的 分析间变型星形细胞瘤的螺旋CT和磁共振影像表现,以提高对本病的认识.方法 回顾性分析颅内间变性星形细胞瘤螺旋CT和磁共振影像表现,使用GE64排螺旋CT和GE 3.0T磁共振,所有病例均进行CT平扫+增强扫描和磁共振SE序列T1WI和T2WI、DWI、MRS、FLAIR序列及对比增强T1WI扫描.结果 间变型星形细胞瘤在螺旋CT和磁共振扫描时密度或信号多不均匀,增强后可见不规则斑片样强化,占位效应明显.MRS显示病灶Cho/NAA的比值5.5～6.3,Cho/Cr比值4.7～5.3.结论 间变型星形细胞瘤的CT及MRI表现具有一定的特征性,螺旋CT和磁共振影像学检查有助于间变型星形细胞瘤的诊断和鉴别诊断.     

脑胶质瘤的^1H磁共振波谱特点及临床意义

目的探讨人脑胶质瘤质子磁共振波谱（^1HMRS）的特点及临床意义。方法22例脑胶质瘤患者术前行MRI检查的同时作^1HMRS分析,并以20例对侧正常的相应部位作为自身对照,比较N-乙酰门冬氨酸（NAA）、胆碱（Cho）、肌酸（cr）和乳酸（Lac）以及Cho／Cr、NAA／Cr、NAA／Cho比值的变化。结果与对照脑区比,脑胶质瘤在^1HMRS上均表现为明显增高的Cho峰（P〈0．01）,NAA、Cr峰下降或消失（P〈0．05）,Cho／Cr比值升高,NAA／Cr比值降低（P〈0．05）;它们的变化并与肿瘤不同病理级别密切相关,其差异具有显著性（P〈0．05）。结论 ^1HMRS是研究脑胶质瘤物质和能量代谢的有效方法,能为脑胶质瘤的临床诊断提供帮助。     

1H 磁共振波谱分析在评价多发性硬化轴索损害中的临床价值

目的 探讨1H磁共振波谱分析(1H magnetic resonance spectroscopy,1H MRS)在评价多发性硬化(multiple sclerosis,MS)轴索损害中的临床价值.方法 对36例MS患者(MS组)和26例健康志愿者(健康对照组)行头颅MRI及1H MRS检查,计算脑部代谢产物N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)的水平并比较两组间NAA/Cr和Cho/Cr比值的差异.采用扩展的功能障碍分级法(EDSS)对MS患者进行评分并分析其NAA/Cr、Cho/Cr 比值与EDSS评分间的相关性.结果 MS组NAA/Cr比值(1.44±0.44)显著低于对照组(1.89±0.49)(P＜0.05),MS组Cho/Cr比值(1.92±0.80)显著高于对照组(1.48±0.36)(P＜0.05).MS组NAA/Cr 比值与EDSS评分之间呈负相关(r=-0.503,P＜0.05),Cho/Cr比值与EDSS评分之间无相关性(r=0.14,P＞0.05).结论 MS患者脑部病灶NAA/Cr比值下降可提示MS患者轴索损害的程度.     

Targeting regions with highest lipid content on MR spectroscopy may improve diagnostic yield in stereotactic biopsy.

Gliomas are heterogeneous brain tumors and prognosis and treatment are dependent on the highest histological grade present. Stereotactic biopsy is associated with an inherent risk of sampling error. Magnetic resonance spectroscopy (MRS) uses clinical MR scanners to provide chemical in addition to conventional information. MRS studies in brain tumors have found increased levels of choline-containing compounds (Cho) and decreased levels of N-acetylaspartate (NAA), creatine (Cr) and phosphocreatine (PCr) which are all associated with increased grade of glioma. We propose the use of MRS-guided stereotactic biopsy of astrocytomas to increase diagnostic yield and reduce the sampling error rate. MRS was performed on two patients undergoing stereotactic biopsy for suspected astrocytoma. Spectral peak heights of the metabolites Cho at 3.2 parts per million (ppm) chemical shift, NAA at 2.0 ppm and lipid (Lip) at 1.2 ppm, were measured. Biopsy targets were selected from the voxels with the highest Cho/NAA and normalised against Cho levels in the contralateral normal tissue, as well as those with highest lipid content. The biopsies were taken and tissue diagnosis was obtained via standard histological techniques. Histological grade was found to be different in one case: the region with a high Lip/Cr and Cho/NAA ratios showed glioblastoma, whereas the region with high Cho/NAA but low Lip/Cr ratios showed anaplastic astrocytoma. The second patient had high Cho/NAA ratio but low Lip/Cr ratio in both targets and the histology revealed anaplastic astrocytoma in both samples. MRS is a useful biomedical imaging tool for diagnosing and grading astrocytomas. Targeting regions with highest lipid content can potentially improve the diagnostic yield and minimize sampling error in stereotactic biopsy.     

Preliminary findings of proton magnetic resonance spectroscopy in occipital cortex during sleep deprivation

Proton magnetic resonance spectroscopy ((1)H MRS) has revealed biochemical alterations in various psychiatric disorders. Changes in brain metabolites may be caused not only by the disease's progression or response to treatment, but also by physiological variability. The aim of this study was to use (1)H MRS to assess the effects of specific short-term physiological states on major metabolites. Eight healthy women underwent (1)H MRS at the beginning and end of a 40-h period of sleep deprivation. The ratios of N-acetyl-aspartate (NAA), total creatine (tCr), and choline-containing compounds (Cho) to water (H(2)O) were determined from the occipital cortex during both baseline and photic stimulation conditions. During sleep deprivation, NAA/H(2)O decreased by 7% and Cho/H(2)O by 12%. Photic stimulation had no effect on the measured metabolites in the alert state, but in the sleep-deprived state the level of Cho/H(2)O increased during neuronal activation. The results suggest that NAA/H(2)O and Cho/H(2)O may depend on the state of alertness.     

质子磁共振波谱用于帕金森病黑质代谢研究价值的探讨

目的探讨质子磁共振波谱（^1H MRS）技术在帕金森病（PD）黑质代谢变化研究中的价值。方法PD患者56例和正常对照30例行^1H MRS检查，测定双侧黑质的N-乙酰天门冬氨酸／肌酸（NAA／Cr）、N-乙酰天门冬氨酸／胆碱复合物（NAA／Cho）和胆碱复合物／肌酸（Cho／Cr）比值。结果PD患者和对照组黑质的NAA／Cr、Cho／Cr和NAA／Cho比值无显著性差异。PD患者的^1H MRS结果与UPDRS评分、H＆Y分级和病程均不存在显著相关性。结论目前的^1H MRS技术尚不能精准地反应PD患者黑质的代谢变化。     

脑干及小脑病变的质子磁共振波谱研究

目的探讨质子磁共振波谱（^1HMRS）分析对脑干及小脑病变的诊断价值。方法对15例健康志愿者和18例脑干及小脑病变患者分别进行^1HMRS采集,定量分析N-乙酰天门冬氨酸（NAA）、肌酸（Cr）和胆碱（Cho）代谢物的变化。结果肿瘤组NAA／Cr、NAA／（Cho＋Cr）的比值低于非肿瘤组,且两者都低于对照组,有显著的统计学差异（P〈0．05）;肿瘤组Cho／Cr的比值高于非肿瘤组,且两者都高于对照组,有显著的统计学差异（P〈0．05）。结论^1HMRS对脑干和小脑病变的定性诊断及预后评估有重要价值。     

<Superscript>1</Superscript>H MR spectroscopy of gray and white matter in carbon monoxide poisoning

Carbon monoxide (CO) intoxication leads to acute and chronic neurological deficits, but little is known about the specific noxious mechanisms. ¹H magnetic resonance spectroscopy (MRS) may allow insight into the pathophysiology of CO poisoning by monitoring neurochemical disturbances, yet only limited information is available to date on the use of this protocol in determining the neurological effects of CO poisoning. To further examine the short-term and long-term effects of CO on the central nervous system, we have studied seven patients with CO poisoning assessed by gray and white matter MRS, magnetic resonance imaging (MRI) and neuropsychological testing. Five patients suffered from acute high-dose CO intoxication and were in coma for 1–6 days. In these patients, MRI revealed hyperintensities of the white matter and globus pallidus and also showed increased choline (Cho) and decreased N-acetyl aspartate (NAA) ratios to creatine (Cr), predominantly in the white matter. Lactate peaks were detected in two patients during the early phase of high-dose CO poisoning. Two patients with chronic low-dose CO exposure and without loss of consciousness had normal MRI and MRS scans. On follow-up. five of our seven patients had long-lasting intellectual impairment, including one individual with low-dose CO exposure. The MRS results showed persisting biochemical alterations despite the MRI scan showing normalization of morphological changes. In conclusion, the MRS was normal in patients suffering from chronic low-dose CO exposure; in contrast, patients with high-dose exposure showed abnormal gray and white matter levels of NAA/Cr, Cho/Cr and lactate, as detected by ¹H MRS, suggesting disturbances of neuronal function, membrane metabolism and anaerobic energy metabolism, respectively. Early increases in Cho/Cr and decreases of NAA/Cr may be related to a poor long-term outcome, but confirmation by future studies is needed.     

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.     

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.     

磁共振表观弥散系数及多体素磁共振波谱与脑胶质瘤增殖活性的相关性研究

目的探讨磁共振弥散加权成像(DWI)的表观弥散系数(ADC)值及多体素氢质子磁共振波谱(1H-MRS)所示代谢物比值与不同级别胶质瘤增殖活性的相关性及其应用价值。方法 2009年12月至2011年9月术前行DWI及多体素1H-MRS检查、术后病理学结果为脑胶质瘤病人40例,按照WHO标准分为低级别胶质瘤组(Ⅰ~Ⅱ级)与高级别胶质瘤组(Ⅲ~Ⅳ级),各20例;对比分析胶质瘤实质部位主要代谢物N-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)比值(NAA/Cr、Cho/Cr、NAA/Cho)及ADC值、相对ADC(rADC)值在不同级别胶质瘤的变化及其与在相应肿瘤组织中Ki-67表达的相关性。结果高级别胶质瘤组Ki-67表达水平、Cho/Cr比值明显高于低级别胶质瘤组(P<0.01),而其ADC值、rADC值、NAA/Cr比值和NAA/Cho比值则明显低于低级别胶质瘤组(P<0.01)。相关分析表明,Cho/Cr值与Ki-67标记指数呈正相关(r=0.849,P<0.01);而NAA/Cho与NAA/Cr比值、ADC和rADC值均与Ki-67标记指数呈负相关(r分别为-0.944、-0.919、-0.935和-0.938,P<0.01)。结论多体素1H-MRS及DWI检查均能有效反应脑胶质瘤的增殖活性,其中瘤体的NAA/Cho比值的诊断价值最高,其联合瘤体的rADC值筛检可大幅提升MR对胶质瘤细胞增殖活性的诊断敏感性。     

Short echo time 1 H magnetic resonance spectroscopy of childhood brain tumours

Aims To explore short echo time (30 ms) 1 H magnetic resonance spectroscopy (MRS) in children with brain tumours and determine the contributions to the characterization of these tumours of the metabolites inositol/myoinositol and glutamate/glutamine, which are not visible at long echo times (135 or 270 ms). Methods Over a 12-month period 86 single-voxel MRS investigations were performed on 59 children with various brain tumours on a Siemens Symphony 1.5-T Magnetom using point-resolved spectroscopy and echo time of 30 ms. Results The procedure was well tolerated, and good-quality data were obtained. N-Acetyl aspartate (NAA)/Choline (Cho) and creatine (Cr)/Cho concentration ratios were significantly (p<0.001) lower in tumour (0.95 and 1.63, respectively) compared with non-involved brain (3.68 and 3.98, respectively) in all histological types. Inositol/Myoinositol (Inos)/Cho ratios were significantly (p<0.05) lower in untreated tumours (1.91) than in treated tumours (3.93) and in non-involved brain (3.32). Inos/Cho ratios were high in diffuse pontine gliomas and low in medulloblastomas and supratentorial primitive neuroectodermal tumours (p<0.01). Glutamate/Glutamine (Glut)/Cho ratios were high in grade 1 astrocytomas (6.4) and unbiopsied optic gliomas (9.84) but low in diffuse pontine gliomas (2.44). Lipids and macromolecules were present in most tumours but in low quantities in non-involved brain. Conclusion Good-quality short echo time MRS data can be collected routinely on children with brain tumours. Inos and Glut levels show greater variability between tumour types than NAA, Cho and Cr present at long echo times, providing improved tumour characterization. Inos/Cho levels differ between untreated and treated tumours and may be useful for treatment monitoring.