阿尔茨海默病多模态MRI研究进展

阿尔茨海默病(AD)是一种以进行性认知障碍和行为异常为主要表现的神经退行性疾病。早期神经放射学多采用结构MRI研究AD局部脑区的改变,随着多模态MRI的发展,研究者们从功能连接、代谢水平、白质纤维成像、血流动力学等方面对AD进一步评价,从而为AD的临床诊断、分期、治疗和预后提供了放射学依据。就多模态MRI技术在AD中的研究进展予以综述。     

帕金森病多模态MRI研究进展

帕金森病(PD)是一种发生率仅次于阿尔茨海默病的神经退行性疾病,其病理改变为黑质内多巴胺能神经元的缺失,引起纹状体内多巴胺含量的减少,进而引起一系列临床症状。早期神经影像检查多采用结构MRI研究局部脑区的改变,随着多模态MRI的发展,从血流动力学、脑白质纤维束成像、代谢水平以及功能连接等不同角度可以对PD行进一步研究及评价,从而为PD的临床诊断、治疗及预后提供更多的影像依据。就多模态MRI技术在PD中的研究进展予以综述。     

前列腺癌基因治疗及多模态成像研究进展

前列腺癌是欧美国家老年男性常见的恶性肿瘤之一,病死率高,严重危害老年男性健康。对于前列腺癌治疗,在疾病的早期阶段,前列腺根治术是首选方法。当疾病进展到激素敏感型晚期阶段时,应用内分泌治疗（手术或药物去势治疗）能获取良好的治疗效果,可短时间内延长患者的生命。然而,当前列腺癌进展到激素非依赖型晚期阶段,传统治疗方法疗效不佳。因而,对于前列腺癌而言,早期发现和早期诊断对于疾病的预后是极其重要的。常规医学影像学技术主要用于显示前列腺癌所致的前列腺解剖学改变,无法从细胞和分子水平上显示病变。分子影像学是在分子生物学的基础上发展起来的,它融合了分子生物学技术和常规医学影像学技术,通过分子生物学方法和途径,探究疾病发展过程中细胞和分子水平的异常。多模态成像是将多种分子影像学技术融合而成。近年来,前列腺癌的基因治疗和相关的多模态成像研究取得一定的进展,但是真正能够应用于临床试验阶段的基因治疗策略却少之又少,主要原因在于不能提高基因载体的高效性和特异性。本篇综述从提高基因载体高效性和特异性两方面介绍前列腺癌基因治疗进展,并简要概述前列腺癌多模态成像研究进展。     

多模态磁共振功能成像评估脑胶质瘤IDH1基因状态的研究进展

【摘要】脑胶质瘤是中枢神经系统最常见的肿瘤,近年来随着对脑胶质瘤异柠檬酸脱氢酶( IDH)基因状态的不断研究,IDH1基因突变状态对脑胶质瘤的诊断、治疗及预后判断有着非常重要的意义,通过多模态磁共振成像技术可以从解剖水平、功能水平以及分子水平来评估肿瘤的IDH1突变状态,从而指导临床精确设计治疗方案和为预后评估提供更加准确的影像学信息,进一步提高脑胶质瘤的临床综合诊疗水平。     

克罗恩病多模态磁共振成像

克罗恩病是一种消化道的慢性炎症,多发生于肠道,以往对该病的诊断和随访多依赖于内镜和实验室检查.随着影像技术的发展,诸多的磁共振成像技术被用于克罗恩病的临床研究,这些成像技术丰富了对克罗恩病的研究手段,能够从微结构和微循环的角度讨论克罗恩病,拓宽了研究视野.本文在概括前人研究的基础上,就不同磁共振成像技术的原理、实际应用、问题不足做一综述,并对未来的发展方向提出展望.     

弥漫性原发中枢神经系统淋巴瘤的临床及多模态影像表现

【摘要】目的：探讨弥漫性原发中枢神经系统淋巴瘤（PCNSL）的临床及多模态影像表现,旨在提高影像诊断水平。方法：回顾性分析经病理证实的11例弥漫性PCNSL患者的临床及多模态影像学资料。结果：11例中男7例、女4例,年龄34~67岁,平均（53.5±8.7）岁;临床症状无特异性,病程2周~6个月。6例行血清及脑脊液寡克隆区带检查,3例行自身免疫抗体、中枢脱髓鞘四项检测,均为阴性结果。11例的主要影像表现为非对称性弥漫性脑白质病变,以深部脑白质或皮质脊髓束分布为主。10例行CT平扫,病灶呈稍低密度影5例,低~稍高密度影5例。11例均行MR平扫和增强扫描,病灶在T1WI上呈等~稍低信号,在T2WI上呈稍高信号,FLAIR图像上呈高信号;增强后呈散在斑点状或斑片状强化。5例短期复查,其中4例显示病变大小及强化范围均较前进展,其中2例出现结节或团块状明显强化。9例行DWI检查,7例表现为部分病灶扩散轻度受限,2例表现为病灶扩散明显受限。5例行1H-MRS检查,示病灶区的Cho峰增高、NAA峰减低,3例出现Lac峰、2例可见高耸的Lip峰。5例行SWI检查,病变内磁敏感信号（ILSS）分级均为0级。2例行DTI检查,显示病变区域白质纤维束破坏、中断,FA值明显减低。4例行PET-CT检查,病灶呈稍高代谢3例,高代谢1例。结论：非对称性弥漫性脑白质病变、以深部脑白质或皮质脊髓束分布为主、增强后主要呈斑点状或斑片状强化、短期复查显示病变进展较快时应考虑弥漫性PCNSL的可能,临床资料结合多模态成像可提高对弥漫性PCNSL的诊断准确性。     

多模态影像评估左室逆重构的研究进展

【摘要】左心室逆重构反映了心室重构患者治疗效果及预后情况,对干预患者病程进展具有重要意义。影像技术仍是评价心脏结构及功能的首选方法,不同影像技术在评估左心室逆重构中各具优缺点。多模态影像克服了单一成像技术的局限性,整合不同模态成像信息,能够更加全面地评估心脏形态及功能的改变,为及时评估和精准预测左心室逆重构的发生提供更好的方法。现就多模态影像在评估左心室逆重构中的作用展开综述,旨在为临床诊疗提供系统全面的影像循证依据。     

首发精神分裂症患者脑局部一致性静息态MRI研究

【摘要】目的：采用脑静息态功能磁共振成像（fMRI）局部一致性（ReHo）方法探讨首发精神分裂症患者脑区自发性活动特征,评价内在脑功能状态与外在表现的关联。方法：对符合美国精神障碍诊断与统计手册第四版（DSM-IV）诊断标准的60例首发精神分裂症患者（病例组）和32例健康受试者（对照组）在静息状态下采集fMRI数据,并计算ReHo值,比较两组间ReHo差异,并分析这种变化与阳性阴性症状量表（PANSS）临床症状评分的相关性。结果：与对照组相比,首发精神分裂症患者右背外侧前额叶、左内侧前额叶、双侧壳核ReHo 值增高;双侧枕中回、舌回、梭状回ReHo值减低,差异有统计学意义（Alphaism校正后P<0.05且体素范围k>10）。左内侧前额叶更高的ReHo值与PANSS妄想评分呈正相关（P<0.05）。结论：首发精神分裂症患者静息态时可能存在广泛的自发神经元活动异常,左内侧前额叶更高的激活与妄想相关。     

多模态功能成像及影像组学预测直肠癌放化疗疗效研究进展

既往常规影像技术及直肠指检、内窥镜等检查主要基于肿瘤形态学信息对直肠癌新辅助放化疗进行疗效预测,效果欠佳。而弥散加权成像(diffusion-weighted, DWI)、动态对比增强(dynamic contrast-enhanced, DCE)和正电子发射型计算机断层显像(positron emission com...     

深入开展头颈部多模态磁共振成像应用研究

多模态磁共振成像不仅能显示结构和病变的形态学特点,而且可全面反映血流灌注、血液动力学、代谢情况和水分子改变等功能代谢信息,在全身疾病的诊断、疗效评价预测和发生机制研究中发挥着越来越重要的作用,尤其在脑梗死、神经退行性病变和肿瘤等方面的应用更广、研究更深、发挥的作用更大.近几年,随着包括影像学和临床及基因等相关信息在内的大数据库的建设及应用,以多模态影像学为基础的影像组学研究已经取得了一些初步成果,有望进一步提高疾病的诊断和疗效评估水平.     

基于体素的形态测量学方法对慢性类风湿关节炎患者脑灰质的MR研究

目的 应用基于体素的形态测量学(VBM)方法分析慢性类风湿关节炎(RA)患者相对于健康志愿者脑灰质改变的特点及规律.方法 收集35例慢性RA患者和30例年龄、性别、受教育程度相匹配的健康对照者,使用GE Signa HDxt 1.5T超导MR扫描仪对所有受试者行高分辨率3D-T1全脑结构扫描,利用SPM 12软件的VBM 12方法对扫描图像进行预处理,对慢性RA患者和正常志愿者脑灰质体积采用双样本t检验,探讨慢性RA患者脑灰质改变的特点及其与临床指标的相关性.结果 与对照组相比,VBM结果显示慢性RA患者右侧豆状核,左侧额叶及左侧小脑后叶脑灰质减少,差异脑区脑灰质与临床指标之间无线性相关性.本研究未发现慢性RA组脑灰质比正常对照组增大的区域.结论 慢性RA患者脑灰质减小,提示RA可导致脑结构异常,VBM为评价RA脑形态学异常提供了客观的影像学依据.     

VBM-DARTEL法观察带状疱疹后遗神经痛患者脑灰质体积的形态学改变

目的 观察带状疱疹后遗神经痛(PHN)患者全脑灰质形态学改变,探讨其形态学改变与PHN患者视觉模拟评分(VAS)及病程之间的相关性.方法 对17例PHN患者及17例正常对照的3D T1WI结构图像进行预处理,采用VBM-DARTEL法比较2组分割后的脑灰质体积,并分析脑灰质体积改变与PH患者VAS及病程之间的相关性.结果 相对于正常对照组,PHN患者脑灰质体积减小的脑区包括:双侧眶额区(眶回及直回)、左侧额下回、左侧岛叶、左侧尾状核、右侧扣带回、左侧颞上回、左侧楔叶、双侧小脑前后叶;PHN患者脑灰质体积增加的脑区包括:双侧额上回、左侧额中回、小脑蚓部、脑桥;PHN组两侧半球脑灰质体积改变不对称(左侧>右侧);PHN患者脑灰质体积异常脑区与VAS及病程之间均无相关性.结论 VBM-DARTEL法揭示PHN患者存在广泛脑灰质体积异常,这些改变可能在疼痛的形成及慢性状态维持中发挥重要作用.     

库欣病患者脑功能改变及任务态功能磁共振成像研究

目的 采用情绪评估量表和任务态功能磁共振成像(Task fMRI)技术,分析库欣病(CD)患者脑功能改变及其与精神症状的关系.方法 收集2015年11月-2016年11月在解放军总医院内分泌科住院诊断为库欣病的8例患者,并选取21名年龄、性别和受教育程度相匹配的健康人作为对照组,对其进行Zung抑郁自评量表(SDS)、Zung焦虑自评量表(SAS)、正性负性情绪量表(PANAS)和库欣生活质量量表(Cushing QOL)的评估,并行Task fMRI检查.结果 与对照组相比,CD组患者均存在抑郁、焦虑状态,正性情绪评分低,而负性情绪评分较高.Task fMRI结果 显示,观看正性图片时CD组左侧小脑和右侧中央后回激活程度较对照组减弱,左侧小脑激活程度与16:00点促肾上腺皮质激素(ACTH)水平呈正相关,右侧中央后回激活程度与尿游离皮质醇(UFC)水平呈正相关;观看负性图片时左侧小脑、双侧海马旁回和左侧额下回激活程度较对照组明显减弱,左侧小脑激活程度与0:00点皮质醇水平和焦虑量表评分呈负相关,与UFC水平呈正相关;观看中性图片时左侧小脑和左侧海马旁回激活程度较对照组减弱.结论 CD患者脑功能受损,会出现抑郁、焦虑等精神障碍,通过Task fMRI技术可发现左侧额下回、右侧中央后回、双侧海马旁回和左侧小脑激活程度减弱与之相关.     

Age-related regional brain T2-relaxation changes in healthy adults

Purpose:

To determine normal T2‐relaxation values from different brain areas in healthy adults, assess age‐related T2‐relaxation changes in those sites, and evaluate potential gender‐related T2‐relaxation value differences.

Materials and Methods:

We performed proton‐density and T2‐weighted imaging in 60 healthy adults (male: 38, age range = 31–64 years, mean age ± SD = 46.1 ± 9.3 years; female: 22, age range = 37–66 years, mean age ± SD = 49.5 ± 8.3 years), using a 3.0 Tesla MRI scanner. T2‐relaxation values were calculated voxel‐by‐voxel from proton‐density and T2‐weighted images, and whole‐brain T2‐relaxation maps were constructed and normalized to a common space. A set of regions‐of‐interest were outlined within the basal ganglia, limbic, frontal, parietal, temporal, occipital, thalamic, hypothalamic, cerebellar, and pontine regions using mean background images derived from normalized and averaged T2‐weighted images of all individuals, and regional T2‐relaxation values were determined from these regions‐of‐interest and normalized T2‐relaxation maps. Pearson's correlations were calculated between T2‐relaxation values and age, and male–female differences evaluated with independent‐samples t‐tests.

Results:

T2‐relaxation values typically increased with age in multiple brain sites; only a few regions showed declines, including the putamen and ventral pons. Sex‐related differences in T2‐relaxation values appeared in basal ganglia, frontal, temporal, occipital, and cerebellar regions; males showed higher values over females in these sites.

Conclusion:

Establishment of normative adult T2‐relaxation values over different brain areas, with age and sex as co‐factors, offers baseline values against which disease‐related tissue changes can be assessed. J. Magn. Reson. Imaging 2012;300‐308. © 2011 Wiley Periodicals, Inc.     

Region and tissue differences of metabolites in normally aged brain using multislice 1H magnetic resonance spectroscopic imaging.

Quantitative measurements of regional and tissue specific concentrations of brain metabolites were measured in elderly subjects using multislice proton magnetic resonance spectroscopic imaging ((1)H MRSI). Selective k-space extrapolation and an inversion-recovery sequence were used to minimize lipid contamination and linear regression was used to account for partial volume problems. The technique was applied to measure the concentrations of N-acetyl aspartate (NAA), and creatine (Cr)- and choline (Cho)-containing compounds in cortical gray and white matter, and white matter lesions of the frontal and the parietal lobe in 40 normal elderly subjects (22 females and 18 males, 56-89 years old, mean age 74 +/- 8). NAA was about 15% lower in cortical gray matter and 23% lower in white matter lesions when compared to normal white matter. Cr was 11% higher in cortical gray matter than in white matter, and also about 15% higher in the parietal cortex than in the frontal cortex. Cho was 28% lower in cortical gray matter than in white matter. Furthermore, NAA and Cr changes correlated with age. In conclusion, regional and tissue differences of brain metabolites must be considered in addition to age-related changes when interpreting (1)H MRSI data.     

MRI of late microstructural and metabolic alterations in radiation‐induced brain injuries

Purpose

To evaluate the late effects of radiation‐induced damages in the rat brain by means of in vivo multiparametric MRI.

Materials and Methods

The right hemibrains of seven Sprague‐Dawley rats were irradiated with a highly collimated 6 MV photon beam at a single dose of approximately 28 Gy. Diffusion tensor imaging (DTI), proton MR spectroscopy (¹H‐MRS), T2‐weighted imaging, and T1‐weighted imaging were performed to the same animals 12 months after radiation treatment.

Results

Compared with the contralateral side, a significantly higher percentage decrease in fractional anisotropy was observed in the ipsilateral fimbria of hippocampus (29%) than the external capsule (8%) in DTI, indicating the selective vulnerability of fimbria to radiation treatment. Furthermore, in ¹H‐MRS, significantly higher choline, glutamate, lactate, and taurine peaks by 24%, 25%, 87%, and 58%, respectively, were observed relative to creatine in the ipsilateral brain. Postmortem histology confirmed these white matter degradations as well as glial fibrillary acidic protein and glutamine synthetase immunoreactivity increase in the ipsilateral brain.

Conclusion

The microstructural and metabolic changes in late radiation‐induced brain injuries were documented in vivo. These multiparametric MRI measurements may help understand the white matter changes and neurotoxicity upon radiation treatment in a single setting. J. Magn. Reson. Imaging 2009;29:1013–1020. © 2009 Wiley‐Liss, Inc.     

fMRI在癫大脑网络中的研究进展

癫是神经元异常放电所致的慢性发作性神经功能障碍性疾病,因其发作的反复性、复杂性和多样性,大脑的结构和功能均受到严重损害。近年来,随着功能成像技术的不断发展,功能MR成像(f MRI)在癫中的应用越来越广泛,尤其是静息态f MRI(rs-f MRI)和同步联合脑电图f MRI(EEG-f MRI)的应用揭示了癫复杂网络、结构网络及功能网络改变的特点,为理解癫发病机制提供了重要的帮助。     

抑郁症患者杏仁核、海马形态功能变化的MR研究

目的 综合形态学测量及功能MR检查对抑郁症患者杏仁核、海马形态及功能进行研究,探讨其变化规律及其机制.方法 60例抑郁症患者[按病情及汉密尔顿抑郁量表(HAMD)分为轻(17分≥HAMD＞8分)、中(24分≥HAMD>17分)及重度组(HAMD>24分),每组20例]及20名健康志愿者行MR形态及fMRI扫描,根据形态图像勾画海马和杏仁核,计算其体积,并进行标准化处理.使用统计参数图(SPM)5软件对功能图像进行后处理,得到受试者脑激活图.体积测量数据采用方差分析及多个试验组与1个对照组均数差别比较的Dunnett-t检验进行分析,并分别对患者组海马、杏仁核体积及信号强度与疾病程度(HAMD评分)进行Pearson相关性分析.结果 抑郁症轻、中及重度组海马体积均小于对照组(左侧2296±202,右侧2283±199),以重度组最为显著(左侧1978±176,Dunnett-t=-10.0,P<0.01;右侧1981±171,Dunnett-t=-9.2,P<0.01),中度组次之(左侧2127±180,Dunnett-t=-3.0,P<0.05;右侧2135±183,Dunnett-t=-3.0,P<0.05),轻度组改变轻微(左侧2207±189,Dunnett-t=-1.4,P>0.05;右侧2210±191,Dunnett-t=-1.6,P>0.05).抑郁症组杏仁核体积依病情由轻到重呈由大至小的趋势,对照组左侧为1762±185,右侧为1749±182.轻度组显著增大(左侧1992±200,Dunnett-t=4.8,P<0.01;右侧1989±191,Dunnett-t=5.0,P<0.01),中度组轻度增大(左侧1889±192,Dunnett-t=2.8,P<0.05;右侧1896±195,Dunnett-t=2.8,P<0.05),重度组显著缩小(左侧1539±178,Dunnett-t=-6.8,P<0.01;右侧1543±180,Dunnett-t=-7.0,P<0.01).功能MR显示抑郁症患者杏仁核、海马对负性图片刺激有着更为显著的脑活动信号,并具有一定的规律,轻度组杏仁核最为显著,中度组信号有所减低,重度组信号最弱,但仍高于对照组.抑郁组海马杏仁核体积、信号强度与疾病程度(HAMD评分)均呈明显的相关性(r值范围为-0.80～-0.90,P值均＜0.05).结论 抑郁症患者海马体积缩小,且这种改变可能与杏仁核有关,杏仁核依病情不同而体积不同;抑郁患者杏仁核、海马对负性图片有着更为显著的脑活动信号.

Abstract：

Objective To explore the morphometric and functional alterations of amygdale and hippocampus in patients with depression by anatomical and functional MRI, and try to reveal the pattern and pathogenesis of the changes in depression. Methods Sixty patients (divided equally into mild, moderate and major groups according to patient′s scores of HAMD) and 20 healthy control groups were scanned using T1WI and fMRI. The outlines of hippocampus and amygdale were drawn manually by observer and the volumes were calculated and normalized subsequently. Functional MRI was processed using SPM5 and individual activation map was got subsequently. Dunnett-t test and Pearson correlation analysis were separately used to analyze the morphometric and functional changes and the correlations between cerebral changes and clinical severity. Results The hippocampal volumes of control groups were 2296±202 left for left side and 2283±199 for right side. The hippocampal volumes of depressive patients were smaller than those of control groups, especially for the major group (left 1978±176,Dunnett-t=-10.0,P<0.01,right 1981±171,Dunnett-t=-9.2,P<0.01). The moderate group showed moderate reduced volume(left 2127±180,Dunnett-t=-3.0,P<0.05,right 2135±183,Dunnett-t=-3.0,P<0.05), while the mild ones showed slightly decreased volume (left 2207±189,Dunnett-t=-1.4,P>0.05,right 2210±191,Dunnett-t=-1.6,P>0.05). The amygdale′s volumes of control groups was 1762±185,the right was 1749±182, while those in patient group reduced along with the patient′s condition, i.e., the mild groups (left 1992±200,Dunnett-t=4.8,P<0.01,right 1989±191, Dunnett-t=5.0,P<0.001), the moderate groups (left 1889±192, Dunnett-t=2.8,P<0.05,right 1896±195,Dunnett-t=2.8,P<0.05), and the major groups (left 1539±178,Dunnett-t=-6.8,P<0.01,right 1543±180,Dunnett-t=-7.0,P<0.01).For fMRI study, patient group demonstrated more activation of the amygdale and hippocampus under the stimulations of negative images than controls. Furthermore, the strengthens of activation decreased along with the patient′s condition, i.e., the major ones showed the weakest activation among the patients, though it was higher than that of control group. In patient group, both the volumes and activations of hippocampus and amygdale showed significant negative correlations with HAMD scores(r=-0.80--0.90,P＜0.05). Conclusion The hippocampal volumes of depressive patients reduced, which may be due to the change of the amygdale, and the amygdale′s volumes were changed along with the patient′s condition. There were more activation in the amygdale and hippocampus of depressive patients under the stimulations of negative images.