增强后多体素^1H-MRS对脑胶质瘤、单发转移瘤和脑脓肿的鉴别诊断价值

目的：探讨注射对比剂后多体素^1H-MRS对脑胶质瘤、单发转移瘤和脑脓肿的鉴别诊断价值。方法：搜集脑胶质瘤16例、单发转移瘤19例和脑脓肿6例,均行注射对比剂后多体素^1H-MRS检查。10例年龄匹配的健康志愿者作对比。比较脑胶质瘤与单发转移瘤强化区及强化边缘区胆碱／肌酸（Cho／Cr）、氮-乙酰天门冬氨酸／胆碱（NAA／Cho）、氮-乙酰天门冬氨酸／对侧相应正常脑组织区胆碱（NAA／Cho-n）和胆碱／对侧相应正常脑组织区胆碱（rCho）值的差异,并做统计学分析。结果：各个级别胶质瘤与单发转移瘤强化区之间Cho／Cr值分别为3．1709±2．197和4．3520±2．509,NAA／Cho-n值分别为0．3312±0．301和0．3843±0．223,差异均无统计学意义（P〉0．05）;而NAA／Cho值分别为0．2436±0．220和0．4550±0．240,rCho值分别为1．5426±0．808和0．9129±0．304,差异均有统计学意义（P〈0．05）;强化边缘区之间上述比值分别为Cho／Cr1．6208±0．230和0．9105±0．414,NAA／Cho-n 0．5357±0．250和0．8015±0．374,NAA／Cho 0．4762±0．278和2．4434±1．636,rCho1．1761±0．423和0．5405±0．497,除NAA／Cho-n外差异均有显著统计学意义（P〈0．001）。脑脓肿出现特征性波谱。结论：增强后多体素^1H-MRS对脑胶质瘤、单发转移瘤和脑脓肿的鉴别诊断有重要的临床应用价值。     

3.0T 1H-MRS在颅内常见肿瘤中的应用研究

目的 探讨3.0 T氢质子磁共振波谱(1H-MRS)对颅内常见肿瘤诊断、鉴别诊断、评价治疗效果及在胶质瘤分级中的价值.资料与方法选取经手术病理或临床确诊的69例颅内肿瘤患者.采用GE Signa EXCITE HD3.0T超导型MR扫描仪对所有患者行颅脑常规MRI扫描和二维多体素序列扫描.采用Functool软件包后处理,分别测定病变实质、病变周围及健侧相应区域的胆碱(Cho)/肌酸(Cr)、Cho/N-乙酰天门冬氨酸(NAA)、NAA/Cr比值及肌醇(MI)值的变化,并对结果进行统计学分析.结果 (1)实质区:低级别胶质瘤的Cho/Cr值与高级别胶质瘤、转移瘤及脑膜瘤间差异有统计学意义(P＜0.01);低级别胶质瘤与高级别胶质瘤、脑膜瘤的Cho/NAA比值分别比较有统计学意义(P＜0.05),转移瘤与高级别胶质瘤、脑膜瘤的Cho/NAA比值分别比较有统计学意义(P＜0.05);低级别胶质瘤NAA/Cr比值与高级别胶质瘤、转移瘤分别比较有统计学意义(P＜0.05),转移瘤与脑膜瘤比较有统计学意义(P＜0.05);低级别胶质瘤的MI值与高级别胶质瘤、转移瘤及脑膜瘤分别比较有统计学意义(P＜0.05).(2)瘤周水肿区:高级别胶质瘤Cho/Cr比值与另外三者比较差异有统计学意义(P＜0.05),低级别胶质瘤Cho/Cr比值与转移瘤、脑膜瘤分别比较差异有统计学意义(P＜0.01);低级别胶质瘤Cho/NAA比值与转移瘤、脑膜瘤分别比较差异有统计学意义(P＜0.05),高级别胶质瘤与转移瘤、脑膜瘤分别比较有统计学意义;低级别胶质瘤与高级别胶质瘤NAA/Cr比值差异有统计学意义(P＜0.05);各肿瘤瘤周水肿区MI值比较无统计学意义(P＞0.05).结论 1H-MRS在鉴别诊断颅内肿瘤中有重要价值,可较准确显示肿瘤瘤周浸润情况,结合其他影像征象对胶质瘤分级诊断亦有重要价值.     

2D CSI1H-MRS对不同类别脑肿瘤的鉴别诊断

目的 探讨二维化学位移氢质子磁共振波谱(2D CSI1H-MRS)对胶质瘤、转移瘤、脑膜瘤的鉴别诊断价值.资料与方法 回顾性分析经临床诊断或经手术病理证实的90例患者的MRI及MRS资料,包括胶质瘤45例,转移瘤23例,脑膜瘤22例.计算瘤体及瘤周水肿区的Cho、Cr、NAA的浓度及Cho/Cr、NAA/Cr、NAA/Cho的比值.结果 (1)胶质瘤、转移瘤、脑膜瘤瘤体区的NAA/Cho分别为0.41±0.19、0.56±0.15、0.15±0.07,三组差异均有统计学意义(P＜0.05);(2)胶质瘤、转移瘤、脑膜瘤瘤周水肿区的Cho浓度分别为0.40 ±0.16、0.26±0.09、0.13±0.07,3组差异均有显著统计学意义(P＜0.01),胶质瘤显著高于其他两者,当取Cho＞0.45时,MRS区分胶质瘤的特异性、敏感性、阳性预测值、阴性预测值分别为83%、94%、77.3%、85.7%.结论 2D CSI1H-MRS对胶质瘤、转移瘤、脑膜瘤的鉴别诊断有重要意义.     

高级别胶质瘤和转移瘤的磁共振波谱及灌注成像研究

目的通过磁共振波谱(MRS)及灌注成像(PI)研究肿瘤强化区域、肿瘤周围区域的细胞代谢和血管分布特点,探讨MRS及PI对高级别胶质瘤和转移瘤的鉴别诊断价值。资料与方法23例颅内肿瘤患者,包括高级别胶质瘤(Ⅲ～Ⅳ级)13例,转移瘤10例,行常规MRI、PI和单体素MRS检查。MRS检查主要观察的代谢物有:氮-乙酰天门冬氨酸(NAA),胆碱(Cho),肌酸(Cr/PCr),计算NAA/Cr,Cho/Cr,NAA/Cho比值。PI观察指标为相对脑血容量(rCBV)。采用SPSS10.0软件进行统计学分析。结果MRS提示高级别胶质瘤和转移瘤肿瘤强化区域均出现NAA/Cr与NAA/Cho降低,Cho/Cr升高;两种肿瘤强化区域各项比值之间的比较差异均无统计学意义(P>0.05);高级别胶质瘤肿瘤周围组织亦出现NAA/Cr与NAA/Cho降低,Cho/Cr升高,与转移瘤肿瘤周围组织相比差异均有统计学意义(P<0.05)。高级别胶质瘤和转移瘤肿瘤强化区域的rCBV值分别为4.05±2.04,3.84±2.44,两者之间差异无统计学意义(P>0.05),肿瘤周围组织的rCBV值分别为1.31±0.14,0.56±0.22,两者之间差异有统计学意义(P<0.05)。结论结合肿瘤强化区域与肿瘤周围区域的MRS和PI,有助于提高对高级别胶质瘤和转移瘤的鉴别能力。     

颅内结核瘤的质子MR波谱研究

目的探讨质子MR波谱(1H-MRS)对颅内结核瘤的诊断价值。资料与方法回顾性分析26例颅内结核瘤患者术前或接受治疗前的1H-MRS表现,1H-MRS采用多体素2D1H-MRS,点分辨表面线圈法(PRESS)。比较结核瘤病灶实质和对侧正常脑组织的胆碱(Cho)、肌酸(Cr)、N-乙酰天门冬氨酸(NAA)、Cho/Cr,Cho/NAA、NAA/Cho差异有无统计学意义,观察有无脂质(Lip)峰或氨基酸峰(AAs)出现。结果颅内结核瘤实质部分Cho较对侧升高,差异无统计学意义(颅内结核瘤和对侧正常脑组织Cho分别为366.7±137.4,325.4±126.4,P>0.05),Cr、NAA、NAA/Cho低于对侧,差异有统计学意义(颅内结核瘤和对侧正常脑组织Cr分别为163.6±74.1,300.1±140.5,P<0.01;NAA分别为239.4±96.6,475.3±244.7,P<0.01;NAA/Cho分别为0.74±0.35,1.56±0.60,P<0.01),Cho/Cr、Cho/NAA高于对侧,差异有统计学意义(颅内结核瘤和对侧正常脑组织Cho/Cr分别为2.05±0.63,1.14±0.38,P<0...     

脑胶质瘤周围区的~1H-MRS研究

目的应用多体素氢质子磁共振波谱(1H-MRS)探讨胶质瘤周围区脑代谢改变的特点,评价多体素1H-MRS在胶质瘤周围区的应用价值。方法23例病理证实的脑胶质瘤病人分为低级别组(WHOⅠ～Ⅱ级)13例和高级别组(WHOⅢ～Ⅳ级)10例,所有病例术前均行多体素1H-MRS检查,测量肿瘤实质区、周围区及对侧正常脑组织区代谢产物的相对定量,进行统计学比较。结果多体素1H-MRS显示高级别胶质瘤的周围区与实质区NAA/Cr、Cho/Cr、NAA/Cho值差异有统计学意义(P值均为0.00)。高级别胶质瘤周围区与对侧正常脑组织区NAA/Cr、Cho/Cr、NAA/Cho、Glx/Cr值差异均有统计学意义(P值均为0.00);低级别胶质瘤周围区与实质区NAA/Cr、Cho/Cr、NAA/Cho值差异均有统计学意义(P值均为0.00);低级别胶质瘤周围区与对侧正常脑组织区Cho/Cr、NAA/Cho值差异均有统计学意义(P值分别为0.02、0.00);高级别与低级别胶质瘤实质区NAA/Cr、NAA/Cho、Cho/Cr、Glx/Cr值差异均有统计学意义(P值分别为0.00、0.00、0.03、0.00);高级别与低级别胶质瘤周...     

1H-MRS 对脑转移瘤和恶性胶质瘤的鉴别诊断作用

目的 利用氢质子磁共振波谱(1H-MRS)对脑转移瘤和胶质瘤的肿瘤强化区、瘤周区和对侧正常区进行细 胞代谢水平的检测,试图找出恶性胶质瘤和脑转移瘤的鉴别诊断的依据。 资料与方法 20例恶性胶质瘤和11例 脑转移瘤患者,先行MRI平扫及增强扫描,再对瘤体实质部分、瘤周、对侧正常区行1H-MRS检查,对两种肿瘤的瘤 体、瘤周、对侧正常区的胆碱/肌酸(Cho/Cr)、氮-乙酰天门冬氨酸/肌酸(NAA/Cr)、乳酸/肌酸(Lac/Cr)进行比较。 结果 11例脑转移瘤中,原发瘤分别为乳腺癌,肝细胞癌,卵巢癌,肺癌。20例恶性胶质瘤中,星形细胞瘤Ⅲ级13 例,Ⅳ级7例。两种肿瘤瘤体内代谢物浓度的比值比较,无统计学意义。而转移瘤瘤周Cho/Cr为0．719±0．287,恶 性胶质瘤瘤周Cho/Cr为1．506±0．846,二者有显著性差异(t=2．118,P=0．043)。结论 在传统MRI图像的基础 上,利用1H-MRS对转移瘤和恶性胶质瘤瘤体强化部分的检查不能对二者作出可靠的鉴别,对瘤周的Cho/Cr的检查 是鉴别胶质瘤和转移瘤的重要手段,胶质瘤的瘤周Cho/Cr水平比转移瘤高。     

Cho/Cr-n相对值测定在脑脓肿与坏死囊性变胶质瘤和脑转移瘤鉴别诊断中的价值

目的运用多体素2D1HMRS,探讨胆碱复合物/对侧相应正常脑白质区肌酸(Cho/Cr-n)相对值测定在脑脓肿与坏死囊性变胶质瘤和脑转移瘤鉴别诊断中的价值。资料与方法对经手术病理证实的12例脑脓肿与20例坏死囊性变胶质瘤和脑转移瘤患者,在术前行常规MRI检查及2D1HMRS,测量感兴趣区(ROI)的胆碱(Cho)和肌酸(Cr)相对值,并计算Cho/Cr-n相对值。结果脑脓肿的Cho/Cr-n相对值(1.12±0.25)明显低于坏死囊性变胶质瘤和脑转移瘤的上述指标(2.76±0.73和2.59±0.47)(P<0.01)。结论多体素2D1HMRS的Cho/Cr-n相对值测定在脑脓肿与坏死囊性变胶质瘤和脑转移瘤鉴别诊断中具有重要价值。     

脑胶质瘤周围区的^1H-MRS研究

目的应用多体素氢质子磁共振波谱(1H-MRS)探讨胶质瘤周围区脑代谢改变的特点,评价多体素1H-MRS在胶质瘤周围区的应用价值.方法23例病理证实的脑胶质瘤病人分为低级别组(WHO Ⅰ～Ⅱ级)13例和高级别组(WHOⅢ～Ⅳ级)10例.所有病例术前均行多体素1H-MRS检查,测量肿瘤实质区、周围区及对侧正常脑组织区代谢产物的相对定量,进行统计学比较.结果多体素1H-MRS显示高级别胶质瘤的周围区与实质区NAA/Cr、Cho/Cr、NAA/Cho值差异有统计学意义(P值均为0.00).高级别胶质瘤周围区与对侧正常脑组织区NAA/Cr、Cho/Cr、NAA/Cho、Glx/Cr值差异均有统计学意义(P值均为0.00);低级别胶质瘤周围区与实质区NAA/Cr、Cho/Cr、NAA/Cho值差异均有统计学意义(P值均为0.00);低级别胶质瘤周围区与对侧正常脑组织区Cho/Cr、NAA/Cho值差异均有统计学意义(P值分别为0.02、0.00);高级别与低级别胶质瘤实质区NAA/Cr、NAA/Cho、Cho/Cr、Glx/Cr值差异均有统计学意义(P值分别为0.00、0.00、0.03、0.00);高级别与低级别胶质瘤周嗣区NAA/Cr、NAA/Cho、Cho/Cr、Glx/Cr值差异均有统计学意义(P值均为0.00).结论脑胶质瘤周围区代谢物的改变反映了肿瘤向瘤周组织浸润,对确定胶质瘤的分级及预测侵袭性病变的浸润范围有帮助.     

氢质子磁共振波谱鉴别孤立脑转移瘤与高级别脑胶质瘤的临床应用价值

目的探讨孤立脑转移瘤与高级别脑胶质瘤的MRI、1H-MRS的临床应用价值。方法经手术病理证实的高级别脑胶质瘤(Ⅲ、Ⅳ级脑胶质瘤)25例及孤立脑转移瘤20例,术前均行常规MRI及1H-MRS检查。从病变部位、信号强度、水肿程度、强化形态及出血与否等方面评价孤立脑转移瘤和高级别脑胶质瘤的常规MRI表现;检测肿瘤组织、瘤周组织区和对侧正常脑组织对照区NAA、Cho和Cr的变化,计算出NAA/Cho、NAA/Cr和Cho/Cr的比值。结果(1)孤立脑转移瘤和高级别脑胶质瘤的常规MRI各种表现中仅病变部位和水肿程度在两者间存在差别,P值分别为0.009、0.046;(2)高级别脑胶质瘤和孤立脑转移瘤的肿瘤组织的NAA/Cr和NAA/Cho比值存在显著性差异(P<0.01),但Cho/Cr比值无显著性差异(P>0.05);(3)高级别脑胶质瘤和孤立脑转移瘤的瘤周组织的Cho/Cr比值存在显著性差异(P<0.05),但NAA/Cr和NAA/Cho比值无显著性差异(P>0.05)。结论常规MRI结合1H-MRS表现可望提高鉴别高级别脑胶质瘤和孤立脑转移瘤的可能性。     

多体素~1H-MRS对星形细胞肿瘤边界诊断的研究

目的：探讨多体素^1H-MRS在星形细胞瘤边界诊断中的临床应用价值。方法：对20例经病理证实的星形胶质细胞瘤患者行多体素^1H-MRS检查,采集NAA、Cho、Cr等波峰,计算并比较肿瘤不同区域多种代谢物比值。结果：多体素^1H-MRS示肿瘤区、近侧瘤周区NAA/Cho、NAA/Cr和Cho/Cr平均值与参照区比较差异均有显著性意义（P〈0.05）;高、低级星形细胞瘤间,多组代谢物比值差异具有统计学意义（P〈0.05）。结论：MRS示Ⅲ～Ⅳ级星形细胞瘤在肿瘤区边缘2cm范围代谢物比值仍和参照区差异有显著统计学意义,提示存在肿瘤浸润,Ⅰ～Ⅱ级星形细胞瘤在肿瘤区边缘1cm范围代谢物比值仍和参照区差异有显著统计学意义,提示存在肿瘤浸润。     

多体素1H - MRS在脑肿瘤强化周围区域中的临床应用

目的探讨多体素1H磁共振波谱(1H-MRS)在颅脑肿瘤强化周围区的代谢物改变特点及其鉴别诊断意义。方法脑肿瘤患者35例,多体素1H-MRS采集NAA、Cho、Cr、Lac、L ip、m I和A la峰,分别计算星形细胞瘤、转移瘤、脑膜瘤的肿瘤强化区、强化周围区和正常参照区域的代谢物浓度,计算不同脑肿瘤、同种脑肿瘤不同区域及高、低级胶质瘤各代谢物比值平均值,比较统计学差异,记录Lac、L ip、m I和A la是否出现。结果肿瘤强化区NAA/Cho、NAA/Cr和Cho/Cr平均值与正常参照区比较均有显著性差异(P<0.05);共出现17例Lac峰、7例L ip峰、6例A la峰和6例m I峰;强化周围区,三者的NAA/Cho、NAA/Cr、NAA/nCr、Cho/NAA值具显著性差异;良、恶性胶质瘤间,NAA/Cho、NAA/nCr、Cho/Cr和Cho/nCho值具有统计学差异(P<0.05)。结论多体素1H-MRS对肿瘤强化周围区域的评价,有助于星形细胞瘤与脑转移瘤、脑膜瘤的鉴别诊断及浸润范围的划定。     

阻塞性睡眠呼吸暂停低通气综合征的多体素^1H-MRS研究

目的探讨多体素质子磁共振波谱（1H-MRS）在阻塞性睡眠呼吸暂停低通气综合征（OSAHS）中的临床应用价值。材料与方法分别对20例临床诊断为中重度OSAHS病人（病变组）及年龄、性别相匹配的20名健康志愿者（对照组）行头颅多体素1H-MRS检查,记录两组半卵圆中心区、基底节区各代谢物比值,比较两组间的差异,观察有无乳酸（Lac）峰出现。记录病人相关临床指标,包括：睡眠呼吸暂停和低通气指数（AHI）和夜间平均血氧饱和度（SpO2）,并与各代谢物比值进行相关性分析。结果病变组半卵圆中心区NAA/Cr、NAA/Cho低于对照组,Cho/Cr高于对照组,差异有统计学意义（P〈0.05）。基底节区NAA/Cr、NAA/Cho较对照组稍降低,Cho/Cr较对照组稍升高,差异无统计学意义（P〉0.05）。两组均未检测到Lac峰。AHI与半卵圆中心区NAA/Cho呈负相关（P〈0.05）,SpO2与NAA/Cho呈正相关（P〈0.05）,而AHI和SpO2与NAA/Cr、Cho/Cr无相关性（P〉0.05）。结论多体素1H-MRI能够早期发现OSAHS脑代谢改变,为临床诊治提供客观的影像学依据。     

In vivo neurobiochemical changes of the posterior cingulate gyrus in patients with Alzheimer’s disease detected by multivoxel proton magnetic resonance spectroscopy

Aim of the work

To study the neurobiochemical changes in patients with Alzheimer’s disease (AD) by multivoxel 1H-MRS.

Materials and methods

Twenty-five patients with probable AD and 12 age- and sex-matched normal controls were subjected to assessment of cognitive functions by the Mini Mental State Examination (MMSE) and imaging with multivoxel 1H-MRS for measuring the NAA/Cho, NAA/Cr, Cho/Cr, MI/NAA and MI/Cr ratios in the posterior cingulate gyrus (PCG) bilaterally.

Results

Patients with AD showed significant decrease in NAA/Cho and NAA/Cr, significant increase in MI/NAA and MI/Cr and non-significant increase in Cho/Cr ratios compared to control. Also, the severity of cognitive impairment was significantly associated with these changes. The NAA/Cho ratio at a cut-off value ?1.14 showed accuracy (94%), the NAA/Cr ratio at a cut-off value ?1.40 showed accuracy (97%), the Cho/Cr ratio at a cut-off value >1.29 showed accuracy (85%), the MI/NAA ratio at a cut-off value >0.60 showed accuracy (98%), and the MI/Cr ratio at a cut-off value >0.83 showed accuracy (97%).

Conclusion

The multi-voxels 1H-MRS of the PCG is sensitive to biochemical changes in AD. The 1H-MRS peak metabolite concentration ratios may be useful as markers for the progression of AD.     

Interictal alterations of thalamic metabolic concentration ratios in migraine without aura detected by proton magnetic resonance spectroscopy

Aim of the work

To detect interictal changes of the metabolic concentration ratios in the thalami of patients with migraine without aura by using 1H-MRS.

Materials and methods

Twenty-two patients of migraine without aura were enrolled in this study in addition to 10 healthy controls. Patients were further divided into 2 subgroups; 12 with left-sided migraine and 10 with right-sided migraine. Patients were imaged interictally with multivoxel 1H-MRS for measuring the NAA/Cho, NAA/Cr, Cho/Cr, MI/NAA and Lac/NAA ratios in both thalami.

Results

Each of the mean NAA/Cho and NAA/Cr ratios was significantly decreased in patients compared to controls, and also on the contralateral side compared to the side of migraine in each subgroup of patients. In contrary, no significant difference was found in Cho/Cr, MI/NAA and Lac/NAA ratios between patients and controls, as well as on comparing both sides in each subgroup of patients. Furthermore, increased duration of illness and frequency of attacks were significantly associated with decreased NAA/Cho and NAA/Cr ratios as well as increased MI/NAA and Lac/NAA ratios.

Conclusion

Migraine without aura is associated with thalamic interictal changes in the mean metabolite concentration ratios, detected with multivoxel 1H-MRS.     

中重度OSAHS患者CPAP治疗前后1H-MRS变化的初步研究

目的：用多体素磁共振波谱(1 H-MRS)探讨阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者持续正压通气(CPAP)治疗前后的变化。方法对25例进行 CPAP 治疗前后的中重度男性 OSAHS 患者及与其性别、年龄相匹配的25例健康对照者的双侧额叶均行头颅多体素1 H-MRS 检查。分别记录额叶各代谢物比值,比较两两之间的差异,并观察有无乳酸(Lac)峰出现。结果治疗前额叶 NAA/Cr、NAA/Cho(2.0212±0.2312和1.6088±0.2571)较健康对照者(2.7268±0.6071和2.4456±0.4375)减低,治疗后额叶 NAA/Cr、NAA/Cho(2.3140±0.3128和2.0164±0.4240)较治疗前(2.0212±0.2312和1.6088±0.2571)升高,治疗后额叶 NAA/Cr、NAA/Cho(2.3140±0.3128和2.0164±0.4240)较健康对照者(2.7268±0.6071和2.4456±0.4375)减低(P <0.01)。治疗前 Cho/Cr(1.2932±0.2615)较健康对照者(1.1292±0.1577)升高(P <0.05)。3组均未检测到 Lac 峰。结论多体素1 H-MRS 能敏感显示 OSAHS 患者 CPAP 治疗前后脑代谢的改变,提供临床疗效及预后评估的影像学依据。     

Usefulness of Cho/Cr ratio in proton MR spectroscopy for differentiating residual/recurrent glioma from non-neoplastic lesions

PURPOSE: We evaluated the clinical usefulness of the Cho/Cr ratio of proton MR spectroscopy(1H-MRS) to differentiate residual/recurrent glioma from non-neoplastic lesions. PATIENTS AND METHODS: 20 cases of glioma were involved in this study(astrocytoma grade I-II: 7, oligodendroglioma: 1, astrocytoma grade III: 2, glioblastoma: 10). Seven of the patients underwent surgical resection only, 4 underwent surgical resection and radiotherapy(40-60 Gy), and 9 underwent surgical resection and radiotherapy with concurrent chemotherapy(14-60 Gy). 1H-MRS was performed on a 1.5 Tesla clinical MR unit using a 3D-chemical shift imaging sequence(1500 msec/270 msec/1 (TR/TE/excitations), and the Cho/Cr ratio was calculated in the voxel where neoplastic lesion was most suspected on MRI. The presence of lactate + lipid peak was also evaluated. All spectra were obtained after the contrast enhanced study. RESULTS: Cho/Cr ratios were significantly higher in cases of residual/recurrent tumors(mean +/- SD = 1.70 +/- 0.96) than in non-neoplastic lesions(mean +/- SD = 1.04 +/- 1.16) (Mann-Whitney U-test p = 0.047). If a Cho/Cr ratio of more than 1.5 was used as a marker of tumor presence, its sensitivity was 64%, specificity 83%, and accuracy 70%. One false-positive case that of radiation necrosis whose spectrum showed a high Cho/Cr ratio with markedly elevated lactate + lipid peak. CONCLUSION: The Cho/Cr ratio of 1H-MRS provides additional information to MRI in differentiating residual/recurrent gliomas from non-neoplastic lesions.