急性颈髓损伤1H-MRS与MRI的对照研究

目的对照研究磁共振质谱(1H-MRS)与MRI对急性颈髓损伤的诊断价值.方法根据19例急性颈髓损伤患者的MRI表现,分为脊髓正常信号组(损伤组Ⅰ)和脊髓异常信号组(损伤组Ⅱ),并以9例健康者作对照.进行1H-MRS检查,并计算氮-乙酰天门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)、乳酸(Lac)波峰面积,分析NAA/Cho、NAA/Cr、Cr/Cho、Lac/Cho.结果损伤组Ⅰ与对照组比,仅Lac/Cho值升高(P＜0.05).损伤组Ⅱ与对照组比,NAA/Cho、NAA/Cr值降低,Lac/Cho值升高(P＜0.01).损伤组Ⅱ较损伤组Ⅰ NAA/Cho、NAA/Cr显著减低(P＜O.05).结论1H-MRS可定量测定创区颈髓相关代谢介质的变化,从代谢水平反映颈髓损伤的不同程度.MRI结合1H-MRS更有利于颈髓损伤评价.     

磁共振氢质子波谱鉴别软组织肿瘤良恶性的价值

目的探讨1H-MRS在软组织肿瘤定性诊断中的应用价值。方法收集经手术及病理证实的12例良性和10例恶性软组织肿瘤患者,分析其1H-MRS各代谢物浓度比值（Cho/Cr、Cho/NAA、Cr/NAA）及其相关性。结果①恶性和良性软组织肿瘤Cho/Cr比值分别为3.72±2.76、0.88±0.53,差异有统计学意义（P〈0.05）,Cho/NAA和Cr/NAA差异均无统计学意义（P均〉0.05）。②良性软组织肿瘤Cr浓度与Cho及NAA浓度均呈正相关（r=0.884、0.822,P均〈0.01）,其余代谢物浓度间均无相关性（P均〉0.05）。③恶性软组织肿瘤Cr浓度与NAA浓度呈正相关（r=0.952,P〈0.001）,其余代谢物浓度间均无相关性（P均〉0.05）。结论 Cho/Cr比值可作为良、恶性软组织肿瘤鉴别诊断的重要依据。Cho/Cr比值升高提示软组织肿瘤为恶性可能性大;Cho/Cr比值降低提示软组织肿瘤为良性可能性大。     

颈脊髓慢性压迫症的代谢组学研究

目的探讨应用磁共振波谱技术（magneticresonance spectroscopy,MRS）测量颈脊髓慢性压迫症患者脊髓代谢组改变的可行性,探讨脊髓代谢组学与脊髓功能的相关性。方法 2009年1月至2010年6月行减压手术的脊髓型颈椎病（cervical spondylotic myelopathy,CSM）患者13例作为实验组,男8例,女5例;年龄37～84岁,平均58.2岁。术前进行神经系统检查、神经功能评价（JOA评分）和MRS检查,将感兴趣区放置在脊髓受压最严重部位的相邻节段。通过MRS测得以下代谢物的浓度：氮-乙酰天门冬氨酸（NAA）、胆碱（Cho）、肌酸（Cr）、乳酸（Lac）、肌醇（Ins）、谷氨酰氨（Glx）。15名健康志愿者为正常对照组,年龄和性别与实验组无明显差异,同样用MRS测得脊髓代谢浓度。计算以下代谢浓度的比值：NAA/Cr、Cho/Cr、Lac/Cr、Ins/Cr、Glx/Cr。结果实验组的NAA/Cr和Glx/Cr比正常对照组明显降低（1.18 vs 2.58,P=0.023;0.56 vs 1.25,P=0.008）。实验组的NAA/Cr与脊髓JOA评分呈正相关。但是两组其他代谢物浓度比值如Cho/Cr,mI/Cr,Lac/Cr的差异均无统计学意义。实验组患者中有4例出现乳酸峰,而对照组中无一例出现乳酸峰。结论 MRS可以定量测量颈脊髓的代谢组学改变。慢性颈脊髓压迫症患者的NAA/Cr和Glx/Cr较健康志愿者明显降低,说明神经元和轴突的减少和损伤。NAA/Cr与脊髓功能的相关性,提示有评价脊髓功能的临床价值,但尚需大样本的研究来证实。     

颈髓急性损伤后的磁共振波谱评价

目的:探讨颈髓急性损伤后磁共振波谱(1H-MRS)的诊断价值。方法:对19例急性颈髓损伤患者根据神经功能分为完全性损伤及不全性损伤两组,选取创区与创区头侧远端颈髓行1H-MRS,半定量分析氮-乙酰门冬氨酸(NAA)、胆碱(Cho)、肌酸(Cr)和乳酸(Lac)含量的比值。结果:颈髓完全性损伤组中NAA/Cho、NAA/Cr显著减低,Lac/Cho显著增高,其创区头侧远端Lac/Cho含量也增高(P<0.05);不完全损伤组中仅Lac/Cho含量增加,头侧远端乳酸含量亦增高(P<0.05)。颈髓损伤不同程度组间NAA/Cho、NAA/Cr有显著性差异(P<0.05)。结论:1H-MRS所测NAA/Cho、NAA/Cr从代谢水平反映颈髓损伤的不同程度,创区头侧远端Lac/Cho比值增高提示颈髓隐匿损伤的存在。     

1H-MRS检测正常中老年人纹状体和黑质代谢功能

目的探讨中老年人纹状体和黑质1 H-MRS各参数值正常参考范围。方法纳入健康中老年志愿者32名,采用单体素PRESS序列对纹状体、多体素PRESS序列对黑质进行1 H-MRS扫描,分析N-乙酰天门冬氨酸(NAA)、胆碱(Cho)和肌酸(Cr)含量及各参数比值。结果左右侧纹状体和黑质NAA/Cr、Cho/Cr、NAA/Cho、NAA/(Cho+Cr)差异均无统计学意义(P均0.05)。综合两侧结果,纹状体NAA/Cr、Cho/Cr、NAA/Cho、NAA/(Cho+Cr)均值及95%CI分别为1.39(1.33~1.45)、0.90(0.86~0.94)、1.58(1.50~1.66)、0.73(0.70~0.76);黑质上述比值均值及95%CI分别为2.36(1.85~2.87)、1.38(1.12~1.65)、1.70(1.59~1.81)、0.93(0.86~1.00);纹状体及黑质中NAA/(Cho+Cr)比值均最稳定。结论正常中老年人黑质和纹状体1 H-MRS各参数中,NAA/(Cho+Cr)比值最稳定,可为研究累及黑质和纹状体区域的疾病提供正常参照。     

质子磁共振波谱在胶质瘤诊断中的应用

目的探讨质子磁共振波谱（^1Hmagnetic resonance spectroscopy，^1HMRS）在胶质瘤诊断及分级中的应用。方法回顾分析我院2003年3月～2005年9月质子磁共振波谱检查并经病理证实的36例胶质瘤的临床资料，根据胶质瘤恶性程度不同分为A、B2组，其中A组为低恶性组（包括星形细胞瘤Ⅰ级和Ⅱ级、室管膜瘤、少突胶质细胞瘤等）21例，B组为高恶性组（包括星形细胞瘤Ⅲ级和Ⅳ级、多形性胶质母细胞瘤、间变型室管膜瘤、髓母细胞瘤）15例。观察氮乙酰门冬氨酸（Nacetylaspartate，NAA）、胆碱（choline，Cho）、肌酸（creatine，Cr）、肌醇（Ins）的共振峰及比值。大脑对侧对应正常脑组织的结果作内对照组。结果2组胶质瘤均表现为异常的。HMRS，与大脑对侧对应正常脑组织相比，A、B2组表现为NAA／Cr含量显著下降，Cho／Cr含量显著增高（P均〈0．05），cr总量变化不大，且无规律性（P〉0．05），Ins含量表现为轻度下降（P〉0．05）。A组NAA／Cr和NAA／Cho均显著高于B组（t=4．235，P=0．011；t=2．832，P=0．031），A组Cho／Cr显著低于B组（t=-2．323，P=0．042）。结论。HMRs可提高对胶质瘤诊断和分级的准确性。     

原发性中枢神经系统淋巴瘤常规及功能磁共振成像特点

目的探讨原发性中枢神经系统淋巴瘤(PCNSL)常规MRI及fMRI特点。方法回顾性分析21例经病理证实的PCNSL的常规MRI及DWI、1 H-MRS、PWI表现。结果 21例患者共39个PCNSL病灶的ADC值为(0.78±0.14)×10-3 mm2/s,对侧半球正常脑白质ADC值为(0.89±0.21)×10-3 mm2/s,二者差异有统计学意义(t=1.24,P0.05)。相对于正常脑白质,PCNSL病灶1 H-MRS波谱表现为Cho/Cr值增高(4.62±2.05vs 0.83±0.25)、Cho/NAA值增高(6.86±2.36vs 0.63±0.34)、NAA/Cr值减低(0.67±1.73vs 0.63±.034),差异均有统计学意义(P均0.05)。PCNSL病灶PWI表现为相对低灌注,脑血容量低于周围正常脑实质。结论采用MR DWI、1 H-MRS、PWI可从不同方面反映PCNSL的特征,结合常规MRI征象可进一步提高诊断准确率。     

磁共振氢质子波谱扫描代谢物相对浓度鉴别软组织肿瘤良恶性

【摘要】目的：探讨磁共振氢质子波谱成像在软组织肿瘤定性诊断中的应用价值。方法：研究均经手术及病理证实的12例良性和10例恶性软组织肿瘤,对照分析良、恶性软组织肿瘤1H-MRS代谢物浓度及比值。结果：①恶性软组织肿瘤代谢物浓度Cho/Cr比值为(3.72?.76),良性肿瘤代谢物浓度Cho/Cr比值为(0.88?.53),两者Cho/Cr之间的比值差异有显著性（P〈0.01）。②良性软组织肿瘤代谢物浓度Cho与Cr值及Cr与NAA值之间的差异有显著性（r=0.884,P<0.01; r=0.822,P<0.001）;良性肿瘤代谢物浓度Cho与NAA值、Cho与LL值、Cr与LL值及NAA值与LL值之间的差异无显著性(P>0.05)。③恶性软组织肿瘤代谢物浓度Cr与NAA值之间的差异有显著性（r=0.952,P<0.01）;恶性肿瘤代谢物浓度Cho与Cr值、Cho与NAA值、Cho与LL值及Cr与LL值之间的差异无显著性 (P>0.05)。结论： Cho/Cr比值可作为软组织肿瘤良、恶性鉴别诊断的重要依据。Cho/Cr比值升高提示软组织肿瘤为恶性可能性大;Cho/Cr比值降低提示软组织肿瘤为良性可能性大.     

心理性勃起功能障碍的海马氢质子波谱研究

目的:研究心理性勃起功能障碍(ED)患者海马代谢的改变,以期为心理性ED可能存在的潜在病因和病理生理机制的探讨提供线索。方法:运用磁共振波谱(MRS)研究15例心理性ED患者和15例年龄匹配的健康志愿者双侧海马的多体素氢质子(1H-MRS)波谱特点,测定N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)代谢物浓度,并分别对NAA/Cr和Cho/Cr的比值进行计算。结果:NAA/Cr在心理性ED组两侧海马(左侧为1.03±0.18,右侧为1.05±0.12)均低于正常对照组(左侧为1.25±0.10,右侧为1.21±0.07),差异有显著性(P<0.05);两组两侧Cho/Cr均无明显差异(心理性ED组左侧为1.20±0.82,右侧为1.22±0.95;对照组左侧为1.21±0.93,右侧为1.18±0.12)。结论:心理性ED可能不单纯是功能性疾病,海马可能参与了心理性ED的病理生理过程,心理性ED可能存在潜在的病因和病理生理机制。     

氢质子磁共振波谱成像联合磁敏感成像评价弥漫性轴索损伤

目的探讨评价氢质子磁共振波谱（^1H—MRS）和磁敏感成像技术（susceptibility weighted imaging,SWI）在弥漫性轴索损伤（diffuse axonal injury,DAI）的早期诊断治疗中的价值。方法选择2009年9月至2010年8月收治DAI患者24例,分别在伤后1周、1个月行^1H—MRS和SWI检查,再随机选择20例健康成年人作为对照组。比较各组胼胝体压部和基底节N一乙酰天冬氨酸（N—acetylaspartate,NAA）／肌酸和磷酸肌酸（creatine compound,Cr）、胆碱复合物（choline—containing compounds,Cho）／Cr、肌醇（mlNs）／Cr以及谷氨酸和谷氨酰胺（Glx）／Cr等指标的差异。观察T：序列对DAI组病例的检出率;SWI序列观察微出血像素数目及微出血灶检出数。结果与对照组相比,DAI伤后1周、1个月组胼胝体压部NAA／Cr、Cho／Cr、mlNs／Cr、GLx／Cr、基底节区NAA／Cr、Cho／Cr的差异有统计学意义。T2及SWI对轴索病灶的检测率明显提高。24例DAI患者均有微出血。SWI序列及T2序列在微出血像素数及微出血灶数比较差异有统计学意义。结论磁共振波谱技术可反映弥漫性轴索损伤不同时间段局部组织代谢变化,SWI则可检测到微小出血灶,两者结合可更早明确弥漫性轴素损伤的诊断。     

Characterizing 'mild' in traumatic brain injury with proton MR spectroscopy in the thalamus: Initial findings

OBJECTIVE: Although most mild traumatic brain injury (mTBI) patients suffer any of several post-concussion symptoms suggestive of thalamic involvement, they rarely present with any MRI-visible pathology. The aim here, therefore, is to characterize their thalamic metabolite levels with proton MR spectroscopy (1H-MRS) compared with healthy controls. METHODS: T1-weighted MRI and multi-voxel 1H-MRS were acquired at 3 Tesla from 20 mTBI (Glasgow Coma Scale score of 15-13) patients, 19-59 years old, 0-7 years post-injury; and from 17 age and gender matched healthy controls. Mixed model regression was used to compare patients and controls with respect to the mean absolute N-acetylaspartate (NAA), choline (Cho) and creatine (Cr) levels within each thalamus. RESULTS: The mTBI-induced thalamic metabolite concentration changes were under +/- 13.0% for NAA, +/- 13.5% for Cr and +/- 18.8% for Cho relative to their corresponding concentrations in the controls: NAA: 10.08 +/- 0.30 (mean +/- standard error), Cr: 5.62 +/- 0.18 and Cho: 2.08 +/- 0.09 mM. These limits represent the minimal detectable differences between the two cohorts. CONCLUSION: The change in metabolic levels in the thalamus of patients who sustained clinically defined mTBI could be an instrumental characteristic of 'mildness'. 1H-MRS could, therefore, serve as an objective laboratory indicator for differentiating 'mild' from more severe categories of head-trauma, regardless of the presence or lack of current clinical symptoms.     

The use of magnetic resonance spectroscopy in the subacute evaluation of athletes recovering from single and multiple mild traumatic brain injury

Abstract Advanced neuroimaging techniques have shown promise in highlighting the subtle changes and nuances in mild traumatic brain injury (MTBI) even though clinical assessment has shown a return to pre-injury levels. Here we use (1)H-magnetic resonance spectroscopy ((1)H-MRS) to evaluate the brain metabolites N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr) in the corpus callosum in MTBI. Specifically, we looked at the NAA/Cho, NAA/Cr, and Cho/Cr ratios in the genu and splenium. We recruited 20 normal volunteers (NV) and 28 student athletes recovering from the subacute phase of MTBI. The MTBI group was categorized based upon the number of MTBIs and time from injury to (1)H-MRS evaluation. Significant reductions in NAA/Cho and NAA/Cr ratios were seen in the genu of the corpus callosum, but not in the splenium, for MTBI subjects, regardless of the number of MTBIs. MTBI subjects recovering from their first MTBI showed the greatest alteration in NAA/Cho and NAA/Cr ratios. Time since injury to (1)H-MRS acquisition was based upon symptom resolution and did not turn out to be a significant factor. We observed that as the number of MTBIs increased, so did the length of time for symptom resolution. Unexpected findings from this study are that MTBI subjects showed a trend of increasing NAA/Cho and NAA/Cr ratios that coincided with increasing number of MTBIs.     

Assessment of pain due to lumbar spine diseases using MR spectroscopy: a preliminary report

Background data

There is a considerable difference in pain perception among individuals. In patients with chronic pain, recent studies using fMRI, PET and SPECT have shown that functional changes mainly occurred in the anterior cingulate cortex (ACC), prefrontal cortex (PFC) and thalamus. Brain magnetic resonance spectroscopy (MRS) can evaluate brain chemistry by measuring metabolites such as N-acetyl aspartate (NAA). The purpose of this study was to analyze whether brain MRS could assess pain due to lumbar spine diseases.

Methods

NAA levels were determined relative to the concentration of creatine/phosphocreatine complex (Cr) and choline (Cho), which is commonly used as an internal standard. The NAA/Cr and NAA/Cho ratios in the ACC, PFC and thalamus were compared between six patients with unilateral pain (left side) and six control patients without pain.

Results

In the right thalamus (contralateral side to symptom), the NAA/Cr in the patients with pain was statistically significantly lower compared with the control patients (p < 0.05). Also, in the right thalamus, the NAA/Cho in pain patients was significantly lower compared with controls (p < 0.01). When considering just the right thalamus, there were statistically significant correlations between the numerical rating scale for pain (NRS) and NAA values.

Conclusions

Lumbar pain can be assessed indirectly by analyzing the decrease in NAA concentration in the thalamus.     

Metabolic and cognitive response to human traumatic brain injury: a quantitative proton magnetic resonance study

Proton magnetic resonance spectroscopy (1H-MRS) offers a unique insight into brain cellular metabolism following traumatic brain injury (TBI). The aim of the present study was to assess change in neurometabolite markers of brain injury during the recovery period following TBI. We studied 19 TBI patients at 1.5, 3, and 6 months postinjury and 28 controls. We used 1H-MRS to quantify N-acetylaspartate (NAA), creatine (Cre), choline (Cho), and myoinositol (mIns) in occipitoparietal gray matter (GM) and white matter (WM) remote from the primary injury focus. Neuropsychological testing quantified cognitive impairment and recovery. At 1.5 months, we found cognitive impairment (mean z score = -1.36 vs. 0.18,p < 0.01), lower NAA (GM: 12.42 mM vs. 13.03, p = 0.01; WM: 11.75 vs. 12.81, p < 0.01), and elevated Cho (GM: 1.51 vs. 1.25, p < 0.01; WM: 1.98 vs. 1.79, p < 0.01) in TBI patients compared with controls. GM NAA at 1.5 months predicted cognitive function at outcome (6 months postinjury; r = 0.63, p = 0.04). GM NAA continued to fall by 0.46 mM between 1.5 and 3 months (p = 0.02) indicating continuing neuronal loss, metabolic dysfunction, or both. Between 3 and 6 months, WM NAA increased by 0.55 mM (p = 0.06) suggesting metabolic recovery. Patients with poorer outcomes had elevated mean GM Cho at 3 months postinjury, suggesting active inflammation, as compared to patients with better outcomes (p = 0.002). 1H-MRS offers a noninvasive approach to assessing neuronal injury and inflammation following TBI, and may provide unique data for patient management and assessment of therapeutic efficacy.     

Metabolic changes in the ischemic penumbra after carotid endarterectomy in stroke patients by localized in vivo proton magnetic resonance spectroscopy (1H-MRS).

Carotid endarterectomy (CEA) is known to be effective in reducing recurrent ischemic attacks, sometimes accompanied with the functional improvement, for patients with internal carotid artery (ICA) flow lesions by increase in perfusion and/or removal of embolic sources. However, the exact mechanism of how the CEA affects the cerebral metabolism in relations to the perfusion increase in noninfarcted hypoperfused peripheral areas to the center of the lesion (e.g., ischemic penumbra or border zone) is not yet clearly known. The existence of the ischemic penumbra and its long-term viability has also been argued. We designed a prospective study to investigate the metabolic changes in the ischemic penumbra for patients with ICA flow lesions and cerebral infarct (or ischemia) before and after CEA using localized in vivo proton magnetic resonance spectroscopy ((1)H-MRS). The results of (1)H-MRS showed significantly decreased choline (Cho)/creatine (Cr) and increased N-acetylaspartate (NAA)/Cho ratios in the periphery of the lesion for the patients after CEA as compared to those who underwent only medical treatments. The more significant changes in the cerebral metabolite levels were observed in the patients who showed the improved cerebral perfusion by single photon emission computed tomography after CEA than in those who did not. In conclusion, our data suggest the existence of the ischemic penumbra, which were viable for a longer period than previously thought; CEA seems to improve the cerebral metabolism that may result from the improved perfusion at the ischemic penumbra.     

肌萎缩侧索硬化症患者嗅鞘细胞移植后的短期随防研究及磁共振波谱评价

目的采用运动皮质及相关脑区的质子磁共振波谱检查，分析上运动神经元明显受累的肌萎缩侧索硬化症患者嗅鞘细胞移植后质子谱变化。方法2004年12月～2005年2月，收治7例肌萎缩侧索硬化症（amyotrophic lateral sclerosis，ALS）患者，男3例，女4例。年龄25～67岁。按E1 Eseorial诊断标准确诊。嗅鞘细胞移植术前及术后2周检查其神经功能状态、肌萎缩侧索硬化症功能评分、肌电图和质子磁共振波谱。分别于大脑脚、内囊膝部、内囊后肢、放射冠和中央前回测量N-乙酰天冬氨酸／肌酐和胆碱复合物／肌酐比值。结果7例患者均进入结果分析。嗅鞘细胞移植后2周2例患者功能评分明显改善（ALs功能评分ALSFRs分别由30增至33分，29分增至34分），其余5例保持稳定。7例患者N-乙酰天冬氨酸／肌酐和胆碱复合物／肌酐整体水平降低（1．624降至1．531），但2例改善的患者在其相应的解剖区域N-乙酰天冬氨酸／肌酐升高（NAA／Cr分别由1．236增至1．316，1．438增至1．560）。结论初步研究表明嗅鞘细胞移植术后2周内7例ALS患者中的2例明显改善。质子磁共振波谱是一项适用于肌萎缩侧索硬化评估的无创检查方法，但需更多病例数和长期随访进一步研究。     

Early and sustained alterations in cerebral metabolism after traumatic brain injury in immature rats

Although studies have shown alterations in cerebral metabolism after traumatic brain injury (TBI), clinical data in the developing brain is limited. We hypothesized that post-traumatic metabolic changes occur early (<24 h) and persist for up to 1 week. Immature rats underwent TBI to the left parietal cortex. Brains were removed at 4 h, 24 h, and 7 days after injury, and separated into ipsilateral (injured) and contralateral (control) hemispheres. Proton nuclear magnetic resonance (NMR) spectra were obtained, and spectra were analyzed for N-acetyl-aspartate (NAA), lactate (Lac), creatine (Cr), choline, and alanine, with metabolite ratios determined (NAA/Cr, Lac/Cr). There were no metabolic differences at any time in sham controls between cerebral hemispheres. At 4 and 24 h, there was an increase in Lac/Cr, reflecting increased glycolysis and/or decreased oxidative metabolism. At 24 h and 7 days, there was a decrease in NAA/Cr, indicating loss of neuronal integrity. The NAA/Lac ratio was decreased ( approximately 15-20%) at all times (4 h, 24 h, 7 days) in the injured hemisphere of TBI rats. In conclusion, metabolic derangements begin early (<24 h) after TBI in the immature rat and are sustained for up to 7 days. Evaluation of early metabolic alterations after TBI could identify novel targets for neuroprotection in the developing brain.