磁共振波谱成像对颅脑肿瘤的鉴别诊断价值

目的:分析脑肿瘤的氢质子磁共振波谱成像(1H-MRSI)改变,评价1H-MRSI对颅内常见肿瘤的诊断和鉴别诊断价值.方法:本组共42例颅内肿瘤患者行1H-MRSI检查,其中胶质瘤17例、脑膜瘤14例、脑转移瘤11例.测量比较3种肿瘤的实质强化区、周围水肿区和对侧正常脑组织的代谢物浓度(包括N-乙酰天门冬氨酸、肌酸和胆碱)并进行分析比较.结果:常规MRI检查T1WI上肿瘤多为等、低信号,T2WI上呈不均匀高信号,伴有不同程度强化和周围水肿.脑肿瘤的主要MRS袁现为NAA/Cho、NAA/Cr下降,Cho/Cr升高;3纽肿瘤周围水肿区的NAA/Cho分别为1.0167±0.314,1.4250±0.326和2.2900±1.186,组间比较差异均有显著性意义(P＜0.05);其它代谢物指标(NAA/Cr和Cho/Cr)在3种肿瘤间的差异无显著性意义(P＞0.05).3组肿瘤实质强化区各代谢物比值间差异无显著性意义(P＞0.05).结论:1H-MRSI可无创地分析脑肿瘤的代谢状况,对脑肿瘤的诊断、鉴别诊断均有很大的价值.     

恶性胶质瘤的二维氢质子磁共振波谱研究

研究脑恶性胶质瘤的二维氢质子磁共振波谱(2D1H -MRS)特征及其代谢物变化规律。材料和方法 :经病理学证实的恶性胶质瘤14例(男性8例 ,女性6例 ,年龄19～72岁) ,年龄相近正常对照组15例 ,使用1.5TMRI成像仪 ,PRESS序列 ,TR/TE=1000ms/144ms ,多体素相位矩阵 :16×16 ,FOV :24cm。完成扫描后用随机软件包FuncTool进行分析 ,观察正常对照组(作为外参照)、病例组病灶周边、病变区及对侧正常区(内参照)各主要代谢物变化情况。结果 :14例胶质瘤按WHO标准分类Ⅲ级6例 ,Ⅳ级8例 ,肿瘤实体区NAA/Cho、NAA/Cr、NAA/(Cho +Cr)分别为0.39±0.11 ,1.09±0.38 ,0.28±0.06 ,较正常参照区降低且具显著性差异(p<0.05) ;Cho/Cr和Lac/Cr分别为3.05±1.44 ,0.35±0.59 ,均较参照区升高 ,前者p<0.05 ,后者无统计学差异(p>0.05) ;结合多体素波谱图观察提示恶性胶质瘤Cho升高、NAA下降和出现异常Lac峰 ,同时可显示肿瘤周边区域的Cho升高等异常。结论 :Cho升高、NAA下降和出现异常Lac峰是恶性胶质瘤的主要波谱表现。2D 1H -MRS可检测胶质瘤MRI所示病灶以外区域的代谢异常 ,此对鉴别诊断、立体定向活检和制定治疗方案等有较高临床应用价值     

3.0T MRI上活体鼠脑C6胶质瘤模型多体素1H MRS研究

目的探讨影响鼠脑多体素1HMRS的成像因素及在3.0TMRI上鼠脑C6胶质瘤模型各代谢物比值。方法32只正常雄性SD大鼠,体重250~300g,在右尾状核区接种C6胶质瘤细胞。利用3.0TMRI扫描机、大鼠专用线圈对鼠脑胶质瘤模型肿瘤区行二维多体素1HMRS检查,采用点分辨波谱(PRESS)序列,TR1000ms,TE35ms,视野60mm,层厚4mm,激励次数1;利用波谱后处理软件FuncTool重建C6胶质瘤Cho/Cr、Cho/NAA、NAA/Cr的比值。结果32只行多体素1HMRS检查的鼠脑胶质瘤模型中,其尾状核肿瘤区Cho/Cr的平均值为2.70±0.68、Cho/NAA为1.57±0.29、NAA/Cr为1.04±0.24。在进行多体素1HMRS检查时,关键要选择合适的体素位置,并对匀场进行优化,同时要恰如其分的放置饱和带。结论用3.0TMRI行鼠脑多体素1HMRS检查切实可行,通过测定鼠脑C6胶质瘤模型各代谢物的比值,可为以后的科研工作提供有价值的参考值。     

胶质瘤的质子磁共振波谱

磁共振波谱是目前临床上唯一可无创性地研究人体器官组织代谢、生化改变及化合物定量分析的方法.综述了MRS对于各种化合物分析的意义及其在胶质瘤的分级、预后方面的价值,同时就MRS在胶质瘤与其他颅内肿瘤、放射性坏死鉴别中的作用进行了论述.     

胶质瘤的质子磁共振波谱

磁共振波谱是目前临床上唯一可无创性地研究人体器官组织代谢、生化改变及化合物定量分析的方法。综述了MRS对于各种化合物分析的意义及其在胶质瘤的分级、预后方面的价值,同时就MRS在胶质瘤与其他颅内肿瘤、放射性坏死鉴别中的作用进行了论述。     

脑肿瘤磁共振波谱成像检查中的质量控制

目的探讨脑肿瘤磁共振波谱学检查技术及图像质量影响因素。方法分析137例接受磁共振波谱学检查的脑肿瘤患者的影像学资料。结果优质的图像使检查更易行可靠,更有助于影像诊断。结论检查技术参数的合理选择有助于提高影像质量,是质量控制的关键。     

脑肿瘤^1H磁共振波谱改变

脑肿瘤１Ｈ磁共振波谱改变方虹郭庆林赵海涛张贵祥俞高龙葛芳杰在体１Ｈ磁共振波谱技术已用于许多脑部疾患的研究，该方法可提供有关病变生化代谢方面的信息，对判断肿瘤的性质、病理分级及预后均有价值。现将我院新近对１９例脑肿瘤的初步研究结果报告如下。材料与方法１...     

家犬脑挫裂伤1H-MR波谱研究

目的 探讨家犬脑挫裂伤MR波谱(MRS)表现及其应用价值.方法 家犬10只,200 g砝码1.3 m高以自由坠落方式复制脑挫裂伤动物模型,分6个时间点(1 h、24h、72 h、5 d、8 d和14 d)行常规MR及MRS检查.各时段检查结束后处死家犬,取挫裂伤处脑组织行病理检查.结果 伤后1～24h,N-乙酰天冬胺酸/肌酸(NAA/Cr)、胆碱类化合物(Cho)/Cr及NAA/Cho下降,NAA/Cr分别为0.843±0.214,0.862±0.204,对侧 1.069±0.284,1.048±0.232,t=-7.227,-6.718;Cho/Cr1.181±0.224,1.243±0.134,对侧 1.415±0.305,1.455±0.159,t=-4.332,-4.489;NAA/Cho0.701±0.147,0.536±0.136,对侧 0.832±0.245,0.613±0.165,t=-2.652,-2.665(P值均＜0.05);病理示挫伤处见局部点状出血、灶性坏死、神经轴突肿胀、小胶质细胞轻度增生.伤后72 h至5 d,NAA/Cr开始升高,Cho/Cr于5 d时为1.517±0.197,高于对侧,对侧为1.387±0.214(t=3.758,P＜0.05);镜下示炎性细胞浸润明显,血管周围炎、肉芽及纤维瘢痕形成.伤后8～14 d,NAA/Cr与对侧相比差异无统计学意义(0.895±0.105,0.875±0.153,对侧0.989±0.169,0.990±0.173,t=-2.909,-2.471;P值均＞0.05),Cho/Cr高于对侧(1.457±0.168,1.572±0.374,对侧1.334±0.174,1.366 ±0.352,t=7.312,3.201;P值均＜0.05);病理示炎性反应及胶质增生更加显著,14 d时肉芽肿形成.各时段均未见异常乳酸峰及脂质峰.结论 MRS能无创性检测脑挫裂伤后神经元受损及修复情况,了解其脑组织生化代谢改变,反映损伤的程度,为早期治疗和预后的评价提供理论依据.     

肿瘤坏死因子作用于大鼠C6胶质瘤的1H磁共振波谱研究

目的　采用1H磁共振波谱 (MRS)观察大鼠C6胶质瘤在肿瘤坏死因子 (TNF α)治疗后的代谢改变 ,评价1HMRS在肿瘤疗效观察中的有效指标及应用价值。方法　采用立体定向的方法将C6细胞悬液种植于 3 3只SD大鼠脑尾状核部位 ,高场强磁共振波谱仪观察C6胶质瘤大鼠在腹腔给予TNF α后 3、6、9、12、15d的代谢改变 ,比较N 乙酰门冬氨酸 (NAA)、胆碱类化合物 (Cho)、肌酸和磷酸肌酸 (Cr)及乳酸 (Lac)以及Cho/Cr、NAA /Cr、NAA/Cho积分值的变化 ,进行统计学分析。结果　在给予TNF α后第 3天 ,Cho出现降低 ,在第 15天达到治疗前水平 ,其积分值在未治疗组与 3d组 ,3d组与 6d组以及 9d与 12d组间差异有显著性意义 (P <0 0 5 ) ,而NAA及Cr无明显改变。NAA/Cho在治疗后 3、6以及 9、12d组差异有显著性意义 (P <0 0 5 )。Cho/Cr在用药后第 3、6天下降 ,差异有显著性意义 (P <0 0 5 )。而NAA /Cr无明显改变。结论　1HMRS能够早期观察肿瘤治疗的效果 ,Cho是肿瘤疗效观察的有效指标。     

大脑胶质瘤病磁共振成像结合磁共振波谱成像的诊断价值

目的：探讨磁共振成像（MRI）结合磁共振波谱成像（MRS）对大脑胶质瘤病的诊断价值。方法对15例经活体组织检查或手术病理证实的大脑胶质瘤病患者的临床表现及MRI平扫、增强,MRS影像学资料进行回顾性分析。MRI常规行T1WI、T2WI及FLAIR序列,采用时间飞跃法（TOF）的磁共振血管成像（MRA）,T1WI增强扫描。氢质子MRS采用单体素STEAM序列,并分析N-乙酰天门冬氨酸（NAA）、肌酸（Cr）、胆碱复合物（Cho）等物质峰值改变。结果所有病例均侵犯2个或2个以上脑叶,以颞叶、枕叶、胼胝体、基底节和丘脑等部位侵犯受累常见。病变区T1WI呈低或等低信号、T2WI呈高或混杂高信号、FLAIR上为高信号,未见明显坏死、钙化,受累区域脑组织肿胀,占位效应轻。注射钆喷酸葡胺增强扫描示10例无明显强化、3例斑片状强化、1例结节状强化、1例线状轻度强化。病变区域MRS表现为不同程度NAA降低,NAA/Cr比值降低;Cho上升,Cho/Cr和Cho/NAA的比值上升。结论 MRI结合MRS对大脑胶质瘤病的诊断及鉴别诊断具有临床价值,是目前诊断大脑胶质瘤病的首选影像学方法。     

大鼠C6胶质瘤的MR扩散加权成像及病理对照研究

目的观察大鼠脑C6胶质瘤模型的MR扩散加权成像(DWI)表现,并与肿瘤细胞密度等病理学变化进行对照,分析胶质瘤DWI表现的病理学基础。方法肿瘤细胞接种后12～18d分别对16只肿瘤生长良好的大鼠C6胶质瘤模型进行MR增强及DWI检查,观察胶质瘤MR增强及DWI表现,并与病理学改变进行对照分析。结果7例肿瘤灶增强MRI呈环行强化,表观扩散系数(ADC)图均显示肿瘤中心区域信号明显升高,肿瘤中心与周围区域ADC值分别为[(106.5±11.9)×10-5]、[(78.2±9.2)×10-5]mm2/s,两者之间差异有统计学意义(t=8.26,P<0.01);病理学显示该7只肿瘤灶内部明显坏死,细胞密度明显下降,肿瘤中心及周围区域细胞密度分别为(13±8)%、(40±5)%,两者间差异有统计学意义(t=6.55,P<0.01)。另外9只MR增强扫描肿瘤强化均匀,但其中6只ADC图信号不均匀,中心区及周围区ADC值分别为[(94.1±12.6)×10-5]、[(75.8±11.4)×10-5]mm2/s,两者之间差异有统计学意义(t=5.38,P<0.05)。镜下观察肿瘤中心区域细胞密度下降,肿瘤中心区域及周围区域肿瘤细胞密度分别为(29±4)%、(41±8)%,两者之间差异有统计学意义(t=3.92,P<0.05)。3只ADC图显示信号均匀的肿瘤灶中,其中心区及周围区ADC值分别为[(86.7±9.0)×10-5]、[(84.2±7.6)×10-5]mm2/s,两者之间差异无统计学意义(t=3.41,P>0.05)。镜下肿瘤中心及周围细胞密度分别为(38±7)%、(40±5)%,两者间差异无统计学意义(t=1.92,P>0.05)。结论DWI及ADC的信号差异可以反映胶质瘤内部细胞密度的差异,区别肿瘤内部坏死后的细胞稀疏区和肿瘤增殖旺盛的细胞密集区,为从微观角度观察胶质瘤的结构变化提供了基础。     

Magnetic resonance imaging and 1H-magnetic resonance spectroscopy in amyotrophic lateral sclerosis

We aimed to increase confidence in the combined use of MRI and proton MR spectroscopy (¹H-MRS) in diagnosis of amyotrophic lateral sclerosis (ALS). We investigated 12 patients with ALS, seven definite and five probable, taking into account clinical measures of motor neuron function. On T2-weighted images we found high signal in the corticospinal tract in six and low signal in the primary motor cortex in seven of the 12 patients. Atrophy of the precentral gyrus was apparent in all the patients apart from one with probable ALS. Absolute quantification of cerebral metabolites using ¹H-MRS demonstrated a significantly lower mean concentration of N-acetylaspartate (NAA) in the precentral gyrus of patients with probable and definite ALS (8.5 ± 0.62) than in control subjects (10.4 ± 0.71; P < 0.001). NAA concentration in primary motor cortex correlated with Norris scale scores (r = 0.30; P < 0.0001) but not with the ALS Functional Rating Scale score or disease duration. Significantly lower levels of NAA were detected in patients with low signal in the motor cortex than in those without (P < 0.01). Mean choline (Cho) and creatine (Cr) values did not differ between patients with ALS and controls. Received: 20 July 2000 Accepted: 1 September 2000     

Sodium-23 magnetic resonance brain imaging

Summary This is a review of recent work in²³Na MR imaging. The main emphasis of recent papers has been pulse sequences that, with appropriate postprocessing, give images of the fast, slow, and intermediate components of T2 decay. The assignment of compartmental designation to the T2 component remains a problem except for homogeneous structures easily identifiable anatomically (ventricles, superior sagittal sinus, globe of the eye). Compartmental distribution of sodium is described. The predominance of the interstitial and plasma compartment, the invisibility of part of the intracellular sodium, and the difficulty in imaging the very fast T2 component of visible intracellular sodium make the usual Na spin-echo image essentially an image of the interstitial and plasma space. Use of super paramagnetic iron oxide coupled to dextran as a contrast medium may help to identify the plasma compartment. Because the usual Na MR images are essentially interstitial and plasma images, our own interest is in observing functional changes in these compartments. Another proposed application is the detection of the very fast T2 component in brain tumors to aid in defining tumor grade and extent.Supported in part by the Department of Veterans Affairs Medical Research Service     

Proton magnetic resonance spectroscopy in brain tumours: clinical applications

Parallel to the rapid development of clinical MRI, MR spectroscopy (MRS) has, after starting as an analytical tool used in chemistry and physics, evolved to a noninvasive clinical examination. Most common neuroradiological diagnostic indications for MRS are functional inborn errors, neonatal hypoxia, ischaemia, metabolic diseases, white matter and degenerative diseases, epilepsy, inflammation, infections and intracranial neoplasm. Compared to CT and MRI, well-established morphological diagnostic tools, MRS provides information on the metabolic state of brain tissue. We review the clinical impact of MRS in diagnosis of tumours and their differentiation from non-neoplastic lesions. Received: 3 April 2000 Accepted: 1 September 2000     

增强超高速MRI在犬慢性心肌梗塞的初步应用

目的：应用超高速磁共振成像（ＭＲＩ）观察犬慢性心肌梗塞的心肌灌注。材料与方法：采用聚氯乙烯狭窄器闭胸制备犬慢性心肌梗塞模型。心肌灌注成像的参数包括预备反转脉冲１８０°；ＴＥ２毫秒；ＴＲ４．９毫秒；翻转角８°及采集矩阵６４×６４。静脉注射钆－二乙烯三胺五乙酸（Ｇｄ－ＤＴＰＡ）的同时，在３２秒内获得连续图像。结果：左旋支（ＬＣＸ）或左前降支（ＬＡＤ）致窄术５～１０个月后呈９５％狭窄或闭塞。４条犬左心室壁运动减弱，３条犬为运动消失。在光、电镜下见心肌发生纤维化。注射Ｇｄ－ＤＴＰＡ后，右室、左室及心肌信号逐渐明显增强，正常心肌信号远高于梗塞区心肌（Ｐ＜０．０１）。结论：本研究结果显示Ｇｄ－ＤＴＰＡ增强超高速ＭＲＩ能非创伤地评价心肌缺血     

In vivo proton magnetic resonance spectroscopy of intraventricular tumours of the brain

The aim of this study was to assess the usefulness of proton MR spectroscopy in the diagnosis of intraventricular tumours. Fifty-two intraventricular tumours pertaining to 16 different tumour types were derived from our database. All cases had single-voxel proton MR spectroscopy performed at TE at both 30 and 136 ms at 1.5 T. The Mann-Whitney U test was used to search for the most discriminative datapoints each tumour type. Characteristic trends were found for some groups: high Glx and Ala in meningiomas (p < 0.001 and p < 0.01, respectively), high mobile lipids in metastasis (p < 0.001), high Cho in PNET (p < 0.001), high mI + Gly in ependymoma (p < 0.001), high NAC (p < 0.01) in the absence of the normal brain parenchyma pattern in colloid cysts, and high mI/Gly and Ala in central neurocytoma. Proton MR spectroscopy provides additional metabolic information that could be useful in the diagnosis of intraventricular brain tumors. Grants: This work was funded in part by MEDIVO2 (MEC SAF2005–03650), and Generalitat de Catalunya SGR2005–00863 and XT2004–51. CIBER-BBN is an initiative of “Instituto de Salud Carlos III” (ISCiii) of Spain.     

Magnetic resonance spectroscopy and diffusion imaging in the evaluation of neoplastic brain lesions

MR spectroscopy and apparent diffusion coefficient (ADC) calculation have been used frequently for tumour grading and differentiation during the last decade. The aim of this study is to evaluate whether the combination of these two techniques can improve the diagnostic effectiveness in patients with brain tumour.     

1H chemical shift imaging characterization of human brain tumor and edema

Longitudinal (T1) and transverse (T2) relaxation times of metabolites in human brain tumor, peritumoral edema, and unaffected brain tissue were assessed from point resolved spectroscopy (PRESS) (1)H chemical shift imaging results at different repetition times (TR=1500 and 5000 ms; T1: n=19) and echo times (TE=135 and 270 ms; T2: n=7). Metabolite T1 and T2 relaxation times in unaffected brain tissue corresponded with those published for healthy volunteers. T2 relaxation times were reduced in tumor (choline, N-acetyl aspartate) and edema (choline, creatine) compared with unaffected brain tissue ( p<0.02, each), whereas T1 relaxation times did not change significantly. Choline peak area was increased in tumor, creatine and N-acetyl aspartate were decreased in edema and tumor compared with unaffected brain tissue. Metabolite line widths were increased in tumor. It is concluded that under standard measurement conditions the metabolite profiles are not affected by differential T1 saturation. The short T2 of choline in tumor and edema implies that short-echo-time 1H chemical shift imaging is most suited in the use of choline elevation as tumor marker.