胶质瘤瘤周水肿的磁共振波谱和弥散张量成像研究进展

脑胶质瘤占颅内肿瘤的45%～50%,是中枢神经系统最常见的恶性肿瘤[1],其死亡率也在颅内肿瘤中居首位.胶质瘤易复发,预后差.尽管采用手术、放疗、化疗等综合治疗方法,由于肿瘤呈浸润性生长,与周围组织边界不清,根治困难,尤其对于功能区的胶质瘤,既要保全功能,又要尽可能多的切除肿瘤组织,如何掌握切除范围仍然存在困难.因此,在术前正确判断肿瘤的性质、部位、病理学级别及其与周围重要组织的关系显得尤为重要.目前磁共振技术已迅速发展,磁共振波谱(MRS)和弥散张量成像(DTI)已广泛应用于胶质瘤的诊治中,从而提高了手术切除率,改善了患者的生存质量.     

MRS联合DWI观察实验性兔颅脑爆震伤后高压氧的治疗作用

目的 利用磁共振波谱技术及磁共振弥散加权成像探讨高压氧治疗颅脑爆震伤不同时间段脑局部代谢及水分子运动的变化.方法 90只新西兰大白兔按随机数字表法分成对照组、创伤组和高压氧治疗组,后2组采用600 mg TNT当量纸雷管在兔脑上方6.5 cm垂直距离爆炸制作颅脑爆震伤模型,高压氧治疗组待生命体征稳定后即给予不同疗程的高压氧治疗.于模型制作后1 d、3 d、7 d、14d、21 d等时间点观察兔存活情况,磁共振波谱观察乙酰天门冬氨酸(NAA)/肌酸(Cr)、NAA/胆碱(Cho)+Cr随时间发展的演变过程,磁共振弥散加权成像观察表观弥散系数(ADC)值随时间发展的演变过程.结果 创伤组NAA/Cr均值在损伤后明显下降,7 d后有所回升,高压氧治疗组NAA/Cr均值较创伤组高,比较差异有统计学意义(P＜0.05).创伤组NAA/Cho+Cr均值在损伤后即明显降低,高压氧治疗组NAA/Cho+Cr均值较创伤组高,比较差异有统计学意义(P＜0.05).创伤组兴趣区ADC值在1 d时明显下降,3 d后逐渐上升,高压氧治疗组ADC值均较创伤组高,比较差异有统计学意义(P＜0.05).结论 高压氧可通过改善局部神经元代谢、抑制脑水肿、增强局部胶质增生修复等改善颅脑爆震伤的预后,伤后早期干预可能更有利.

Abstract：

Objective To evaluate the role of magnetic resonance spectroscopy (MRS) and diffusion-weighted MRI (DWI) in detecting regional cerebral metabolic changes and changes of water molecular motion in rabbits after explosive brain injury at different time points of injury after being treated with hyperbaric oxygen therapy. Methods Ninety New Zealand white rabbits were divided into control group, trauma group and hyperbaric oxygen treatment group. The injured models in the later 2 groups were established using 600 mg TNT equivalent of paper detonators in the rabbit brain at the top of 6.5 cm vertical distance. Rabbits in the trauma group and hyperbaric oxygen treatment group were sub-divided into 1, 3, 7, 14 and 21 d treatment groups, respectively. The survival of these rabbits was observed at these time points. Hyperbaric oxygen treatments lasting for 1, 3, 7, 14 and 21 d were given to each hyperbaric oxygen treatment sub-groups, respectively. Performance under MRS was detected and dynamic changes of N-acetylaspartate (NAA)/creatine (Cr) ratio and NAA/choline(Cho)+Cr value were observed with MRS. DWI was employed to detect the dynamic changes of apparent diffusion coefficient (ADC) values. Results The NAA/Cr ratio in the trauma group markedly decreased right after the injury and slightly rose 7 d after the injury. Compared with that in the trauma group, the NAA/Cr ratio in the hyperbaric oxygen treatment group was significantly increased (P＜0.05). The NAA/Cho+Cr value in the trauma group was markedly decreased right after the injury, while that in the hyperbaric oxygen treatment group was obviously increased as compared with that in the trauma group (P＜0.05). ADC values in the region of interest of the trauma group was decreased after 1 d of treatment and gradually increased after 3 d of treatment; the ADC values in the hyperbaric oxygen treatment group was obviously higher than those in the trauma group (P＜0.05). Conclusion Hyperbaric oxygen might improve the prognosis by improving local metabolism of neurons, inhibiting brain edema, and enhancing local gliosis repair;, ultra-early intervention (within one week of injury) may be much favorable for animals/patients after explosive brain injury.     

磁共振DWI对脑脓肿与坏死囊变性胶质瘤的鉴别诊断价值

目的评价磁共振弥散加权成像(DWI)及表观弥散系数(ADC)值在脑脓肿与坏死囊变性胶质瘤鉴别诊断中的作用。方法8例脑脓肿和15例坏死囊变性胶质瘤,均行常规磁共振T1WI、T2WI和DWI检查。观察病变区信号强度,并分别测量脑脓肿、胶质瘤坏死囊变区、周围水肿、对侧正常脑白质及脑脊液的ADC值。结果DWI上所有脑脓肿均呈高信号,而胶质瘤坏死、囊变部分均呈低信号。脑脓肿与胶质瘤坏死囊变区ADC值之间,脑脓肿周围水肿与胶质瘤周围水肿的ADC值之间均有统计学差异。结论DWI与ADC值测量能有效反映脑脓肿与坏死、囊变性胶质瘤的不同液态性质,对其鉴别诊断有重要作用。     

胶质瘤磁共振波谱研究进展

医学磁共振应用技术包括磁共振成像(MRI)和功能磁共振(functional MRI，fMRI)，后者包括磁共振波谱(magnetic resonance spectroscopy，MRS)、弥散加权成像(diffusion weighted imaging，DWI)、灌注加权成像(perfusion weighted imaging，PWI)和皮层激发功能定位成像等。胶质瘤是一类起源于神经上皮组织的肿瘤，在颅内各类型肿瘤中发病率为第一位。目前还没有一种临床和组织学标记物能评价其病理分     

应用 DWI 和 DTI 勾画高级别胶质瘤术后放疗靶区的初步研究

目的：初步探讨MRI弥散加权成像（DWI）和弥散张量成像（DTI）在高级别胶质瘤（HGG）术后放疗靶区勾画中的应用价值。方法对复旦大学附属华山医院上海伽玛医院收治的 HGG术后残留患者做前瞻性研究。所有患者放疗前行DWI和DTI检查,在ADC图和FA图上分别测量残留肿瘤、肿瘤外1 cm区域内（定义为近瘤周区）、1～2 cm区域内（定义为中瘤周区）、2～3 cm区域内（定义为远瘤周区）及3～4 cm区域内（定义为瘤周区外）和对侧正常脑组织的ADC平均值、ADC最小值、FA平均值和FA最小值。结果2013年9月至2014年8月,共有55例HGG患者入组,ADC平均值和最小值呈现从残留肿瘤、近瘤周区到中瘤周区逐渐升高的趋势,并从中瘤周区、远瘤周区到瘤周区外逐渐降低;其中,残留肿瘤与近瘤周区,以及中瘤周区与远瘤周区、远瘤周区与瘤周区外比较,差异均有统计学意义（均P＜0．05）; FA平均值和最小值呈现从残留肿瘤、近瘤周区、中瘤周区、远瘤周区到瘤周区外逐渐升高的趋势,但各区差别无统计学意义（均P＞0．05）。结论本研究初步显示DWI技术可能有助于术后HGG及肿瘤周边组织性质的确定,指导HGG术后放疗靶区的勾画;FA值对于靶区勾画的价值有待进一步研究。     

MRS联合DTI评估帕金森病认知障碍的初步研究

目的探讨1~H-磁共振波谱(1~H-MRS)及弥散张量成像(DTI)技术对早期诊断帕金森病(PD)患者认知障碍(PD-CI)患者脑部损害,探讨其在PD-CI的早期诊断及临床病情评估中的价值。方法采用Mo CA量表对14例PD患者及健康对照进行认知功能评定;应用1~H-MRS采集各感兴趣区(ROI)N-乙酰天门冬氨酸(NAA)、胆碱(Cho)及肌酸(Cr)浓度,计算NAA/Cr、Cho/Cr比值。然后对1~H-MRS所选ROI相同区域进行DTI扫描,测定各向异性分数(FA),并进一步分析三者之间及其与Mo CA评分之间的关系。结果 PD组Mo CA量表得分较对照组明显降低(P0.05),认知障碍明显。PD组额叶、颞叶、纹状体NAA/Cr值与对照组相比明显下降(P0.05),而两组黑质NAA/Cr值、各部位Cho/Cr值对比无明显差异。PD组额叶、黑质FA值与对照组相比明显降低(P0.05),而两组颞叶、纹状体FA值对比无明显差异。PD患者额叶、颞叶平均NAA/Cr值与Mo CA量表得分呈正相关(P0.05);额叶平均FA值与Mo CA量表得分呈正相关(P0.05)。PD患者额叶平均NAA/Cr值与FA值呈正相关(P0.05)。结论 1~H-MRS联合DTI扫描能更好地检测出PD认知障碍的患者可能存在的隐匿性损伤;分别从结构和代谢两方面为PD-CI的早期诊断提供客观指标;额叶NAA/Cr、FA值的下降与认知功能下降相关。     

DWI和MRA在超急性期脑梗死中的临床应用

目的探讨磁共振弥散加权成像(DWI)和血管成像(MRA)在超急性期脑梗死中的临床应用价值。方法回顾性分析48例超急性期脑梗死患者的临床和磁共振资料,全部患者均行CT、常规MRI、DWI和MRA检查。结果 48例超急性期脑梗死的CT、常规T2WI、FLAIR及DWI阳性率分别为0、16.7%、37.5%和100%,MRA显示靶血管正常4例,动脉硬化36例,狭窄16例,闭塞8例。结论 DWI联合MRA能够准确显示责任病灶及靶血管受累情况,为超急性期脑梗死早期溶栓治疗提供切实可行的影像学依据。     

MR扩散加权成像对脑胶质瘤病理分级的临床研究

目的 探讨MR扩散加权成像对脑胶质瘤病理分级的临床应用价值.方法 选择经病理证实的30例脑胶质瘤患者入组研究,患者行MR扩散加权成像,测量肿瘤实质的表观扩散系数(ADC)、相对表观扩散系数(rADC)值,并进行统计学分析.结果 30例脑胶质瘤中低级别胶质瘤14例(Ⅰ级1例,为毛细胞型星形细胞瘤;Ⅱ级13例,其中星形细胞瘤11例.1例为术后复发,另室管膜瘤、少突胶质细胞瘤各一例),高级别胶质瘤16例(Ⅲ级11例,均为间变性星形细胞瘤,1例为术后复发;Ⅳ级5例,其中胶质母细胞瘤4例,室管膜瘤1例).低级别胶质瘤的ADC、rADC均值分别为(1.36±0.16)×10-3 mm2/s、1.76±0.23,高级别胶质瘤的ADC、rADC均值分别为(1.08±0.10)×10-3mm2/s、1.36±0.16,高级别与低级别胶质瘤的ADC、rADC均值比较差异有统计学意义(P<0.05).以低级别胶质瘤肿瘤实质ADC、rADC值的下限1.20×10.3mm2/s、1.53作为判断阈值,本组中诊断正确率分别为86.7%、83.3%.结论 ADC、rADC值对脑胶质瘤病理分级的诊断有较高的准确性.     

弥散张量成像技术对胶质瘤侵袭性的评价

弥散张量成像技术(DTI)是一种白质纤维束成像的无创新技术,不仅可在大体解剖结构上显示白质纤维与胶质瘤的关系,而且可在显微结构水平反映胶质瘤细胞对白质纤维的侵袭破坏程度。本文就DTI在评价胶质瘤侵袭性中的应用进行综述。     

磁共振波谱分析在脑胶质瘤侵袭边界确定中的应用进展

脑胶质瘤是最常见的颅内肿瘤、局部侵袭是脑胶质瘤的一个显著特征．典型的肿瘤有一个中央坏死灶，周围致密肿瘤细胞区．外绕被肿瘤细胞侵袭的脑组织。手术仍是目前临床上最主要和最基本的治疗方法，在保存正常脑组织的前提下尽可能的切除肿瘤一直是脑胶质瘤手术治疗中应遵循的基本原则。     

Combined application of MRS and DWI can effectively predict cell proliferation and assess the grade of glioma: A prospective study

In order to assess combined application of MRS and DWI for prediction cell proliferation and grade diagnosis of glioma, We prospectively collected the Cho/Cr, Cho/NAA, Cr/NAA of MRS and tumor parenchyma ADC (ADC_T), contralateral mirror brain tissue ADC (ADC_H), rADC (rADC = ADC_T/ADC_H). According to postoperative pathology, the patients were divided into two groups: LGG group and HGG group, compared differences of age, gender, Ki67, MRS, DWI between two groups. Next, we analyzed the correlation between MRS, DWI and Ki67. On this basis, the sensitivity and specificity of MRS, DWI and MRS combined with DWI (MRS + DWI) in diagnosis of glioma grade were evaluated. The differences of Ki67, Cho/Cr, Cho/NAA, Cr/NAA, ADC_T, rADC between LGG group and HGG group were statistically significant (p = 0.000, 0.000, 0.000, 0.008, 0.000, and 0.000 respectively). From ROC curve, area under the curve (AUC), sensitivity and specificity of Cho/Cr, Cho/NAA, Cr/NAA, ADC_T, rADC, PRE (MRS + DWI) were (0.901, 86.7%, 85.7%), (0.876, 80.0%, 82.1%), (0.704, 63.3%, 71.4%), (0.862, 82.1%, 83.3%), (0.820, 75.0%, 76.7%), (0.920, 86.7%, 89.3%), respectively. Fisher's linear discriminant functions results suggest: Y₁ = -20.447 + 3.46•X₁ + 17.141•X₂ (LGG), Y₂ = -19.415 + 4.828•X₁ + 14.543•X₂ (HGG). Our study suggested that MRS and DWI can effectively predict cell proliferation preoperative. MRS combined with DWI can further improve sensitivity and specificity in assessing the grade of glioma.     

荧光素钠在高级别胶质瘤手术价值的研 究简

目的评价荧光素钠指导高级别脑胶质瘤手术切除的准确性。方法回顾性分析50例高级别脑胶质瘤病例资料,术前行增强MRI检查,术中在荧光素钠染色下指导手术切除肿瘤,术后行增强MRI、MRS检查,测量并比较胶质瘤术后术腔壁（a区）、肿瘤侧正常脑组织（b区）及对侧相应区域正常脑组织（c区）的Cho／Cr值及差异。结果a区分别与b区、c区比较,差异有统计学意义（P〈0．05）．b区与c区比较,差异无统计学意义（P〉0．05）。结论在高级别胶质瘤手术中,严格按照荧光素钠的染色范围切除肿瘤,不能全切除肿瘤,需在不影响功能的前提下扩大切除。     

IVIM-MRI对人脑胶质瘤的病理分级及IDH1基因突变的评估价值

目的 探讨体素不相干运动扩散加权（IVIM）-MRI对人脑胶质瘤的病理分级及异柠檬酸盐脱氢酶1（IDH1）突变的评估价值。方法 回顾性分析2016年1月至2019年12月术后病理确诊的100例脑胶质瘤的临床资料。术前应用3.0 T MRI扫描仪检查,获取IVIM-MRI参数,包括灌注比例系数（F）、真实扩散系数（D）、伪扩散系数（D*）与表观扩散系数（ADC）。结果 与高级别胶质瘤相比,低级别胶质瘤ADC值与D值明显增高（P<0.05）,而F值与D*值均显著降低（P<0.05）。无论是低级别胶质瘤,还是高级别胶质瘤,IDH1基因突变型病人ADC值显著高于IDH1基因突野生型（P<0.05）。高级别胶质瘤病人中,IDH1基因突变型病人F值、D*值均显著低于IDH1基因野生型（P<0.05）。ROC曲线分析显示,对于鉴别胶质瘤级别,ADC值的最佳临界值为1.091,灵敏度为86.92%,特异度为89.45%;D值的最佳临界值为0.934,灵敏度为78.26%,特异度为94.71%;D*值的最佳临界值为6.161,灵敏度为73.95%,特异度为73.66%;F值的最佳临界值为0.190,灵敏度为56.55%,特异度为100.00%。对于区分IDH1基因型,低级别胶质瘤病人中,ADC值区分IDH1基因突变的最佳临界值为1.181,灵敏度为92.87%,特异度为80.01%;高级别胶质瘤病人中,F值的效能最高,灵敏度为100.00%,特异度为92.87%。结论 IVIM-MRI定量分析可用于胶质瘤术前诊断与分级,并对预测胶质瘤IDH1基因状态具有潜在意义。     

神经节苷脂对缺血再灌注大鼠的脑保护作用

目的 探讨神经节苷脂对缺血再灌注大鼠脑组织的保护作用.方法 建立大鼠大脑中动脉栓塞再灌注模型, 采用磁共振弥散加权成像(DWI)与磁共振波谱(MRS)技术,分别对假手术组、缺血再灌注组、神经节苷脂组大鼠的脑梗死体积、氮-乙酰天门冬氨酸(NAA)及乳酸(Lac)等代谢产物进行比较.结果 神经节苷脂组在缺血再灌注1 h、3 h、6 h时梗死区体积分别为(30.32±8.18)mm3、(35.17±12.45)mm3、(31.4±8.56)mm3,缺血再灌注组分别为(204.6±37.77)mm3、(218.9±67.33)mm3、(213.4±99. 95)mm3,两组各时间点比较差异有统计学意义(均P<0.01).神经节苷脂组在缺血再灌注1 h、3 h、6 h Lac/磷酸肌酸和肌酸(PCr Cr)比值分别为0.09±0.11、0.15±0.18、0.13±0.22,缺血再灌注组分别为1.09±0.34、0.99±0.37、1.16±0.27,两组各时间点比较差异有统计学意义(均P<0.01);神经节苷脂组在缺血再灌注1 h、3 h、6 h NAA /(PCr Cr)比值分别为1.04±0.38、 0.81±0.21、0.77±0.25,缺血再灌注组分别为0.55±0.23、0.57±0.12、0.58±0.13,各时间点两组比较差异有统计学意义(均P<0.01).结论 神经节苷脂通过抑制Lac的生成来间接减少Lac所导致的神经元细胞毒性脑水肿,从而显示其具有显著的脑保护作用.     

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.     

术中磁共振影像神经导航治疗脑胶质瘤的临床初步应用(附61例分析)

目的总结术中磁共振影像(iMRI)神经导航手术治疗脑胶质瘤的初步经验。方法2006年3月～2006年12月,61例脑胶质瘤病人接受iMRI神经导航手术。结果手术总耗时2.5～8.5 h,平均(5.2±1.5)h。图像质量良好49例(80.3%),一般7例(11.5%),差5例(8.2%)。56例图像质量优良的病人中,iMRI扫描次数2～5次,平均(2.6±0.8)次;其中2次32例,3次16例,4次5例,5次3例;24例(42.9%)经iMRI发现肿瘤切除范围未达术前计划,仍需进一步切除。无iMRI相关不良事件发生。结论iMRI神经导航手术治疗脑胶质瘤安全、有效,可实时纠正术中脑移位误差,精确定位脑胶质瘤的影像学边界,定量评估手术切除范围,有效提高肿瘤切除率。     

Differentiation between low-grade and high-grade glioma using combined diffusion tensor imaging metrics

Objective

To ascertain whether diffusion tensor imaging (DTI) metrics including tensor shape measures such as planar and spherical isotropy coefficients (CP and CS) can be used to distinguish high-grade from low-grade gliomas.

Methods

Twenty-five patients with histologically proved brain gliomas (10 low-grade and 15 high-grade) were included in this study. Contrast-enhanced T1-weighted images, non-diffusion weighted b = 0 (b0) images, fractional anisotropy (FA), apparent diffusion coefficient (ADC), CS and CP maps were co-registered and each lesion was divided into two regions of interest (ROI): enhancing and immediate peritumoral edema (edema adjacent to tumor). Univariate and multivariate logistic regression analyses were applied to determine the best classification model.

Results

There was a statistically significant difference in the multivariate logistic regression analysis. The best logistic regression model for classification combined three parameters (CS, FA and CP) from the immediate peritumoral part (p = 0.02), resulting in 86% sensitivity, 80% specificity and area under the curve of 0.81.

Conclusion

Our study revealed that combined DTI metrics can function in effect as a non-invasive measure to distinguish between low-grade and high-grade gliomas.     

Linking late cognitive outcome with glioma surgery location using resection cavity maps

Patients with a diffuse glioma may experience cognitive decline or improvement upon resective surgery. To examine the impact of glioma location, cognitive alteration after glioma surgery was quantified and related to voxel‐based resection probability maps. A total of 59 consecutive patients (range 18–67 years of age) who had resective surgery between 2006 and 2011 for a supratentorial nonenhancing diffuse glioma (grade I–III, WHO 2007) were included in this observational cohort study. Standardized neuropsychological examination and MRI were obtained before and after surgery. Intraoperative stimulation mapping guided resections towards neurological functions (language, sensorimotor function, and visual fields). Maps of resected regions were constructed in standard space. These resection cavity maps were compared between patients with and without new cognitive deficits (z‐score difference >1.5 SD between baseline and one year after resection), using a voxel‐wise randomization test and calculation of false discovery rates. Brain regions significantly associated with cognitive decline were classified in standard cortical and subcortical anatomy. Cognitive improvement in any domain occurred in 10 (17%) patients, cognitive decline in any domain in 25 (42%), and decline in more than one domain in 10 (17%). The most frequently affected subdomains were attention in 10 (17%) patients and information processing speed in 9 (15%). Resection regions associated with decline in more than one domain were predominantly located in the right hemisphere. For attention decline, no specific region could be identified. For decline in information speed, several regions were found, including the frontal pole and the corpus callosum. Cognitive decline after resective surgery of diffuse glioma is prevalent, in particular, in patients with a tumor located in the right hemisphere without cognitive function mapping.     

散发性Creutzfeldt-Jakob病的临床和影像学特点

目的探讨散发性Creutzfeldt-Jakob病(sCJD)的临床和影像学特点。方法回顾性分析4例sCJD患者的临床资料。结果4例sCJD患者均表现为亚急性起病,进行性痴呆,伴有肌阵挛;头颅MRI显示对称性或非对称性大脑皮质彩带样和(或)基底节弥散加权成像(DWI)高信号。结论sCJD的临床特点为进展性痴呆伴肌阵挛,头颅MRI特别是DWI出现高信号为其病变特点。