卒中后抑郁患者的局部一致性降低:静息态功能磁共振成像研究

目的 探讨卒中后抑郁(post-stroke depression,PSD)患者静息态脑功能磁共振成像(functional magnetic resonance imaging,fMRI)特征.方法 分别对13例PSD患者以及无PSD卒中患者进行静息态fMRI扫描,采用局部一致性(regional homogeneity,ReHo)作为指标,分析PSD患者脑功能.结果 与对照组相比,PSD组患者左侧额中回、右侧额上回、右侧额中回、右侧扣带前回、右侧扣带后回、左侧岛叶、左侧尾状核和左侧海马的ReHo值显著降低.结论 PSD患者存在静息态神经环路功能异常,提示在临床治疗过程中需要重视卒中患者的情绪状态.     

静息态功能磁共振在皮质下缺血性血管性认知损害中的应用

皮质下缺血性血管病(subcortical ischemic vascular disease, SIVD)被认为是引起血管性认知损害(vascular cognitive impairment, VCI)的最重要和常见的原因。若能早期发现皮质下缺血性血管性认知损害(subcortical ischemic vascular cognitive impairment, SIVCI)或皮质下血管性认知损害(subcortical vascular cognitive impairment, sVCI)患者,会使血管性痴呆(vascular dementia, VaD)在发生之前得到识别甚至逆转其进程成为可能。最近的研究显示,静息态功能磁共振(resting-state fMRI, rsfMRI)有可能为 SIVCI 的诊断提供客观依据。文章对 rsfMRI 在 SIVCI 诊断中的应用进行了综述。     

主观认知下降患者静息态磁共振局部一致性与功能连接研究

目的:通过联合应用局部一致性(ReHo)和功能连接(FC)对主观认知下降(SCD)患者进行研究,探讨静息态下SCD的机制。方法:对25例SCD及30例性别、受教育年限、民族等相匹配的健康对照组进行静息态功能磁共振(RS-fMRI)扫描,应用DPARSFA2.3和SPM8软件分析筛选SCD组ReHo值异常脑区,以后扣带回...     

轻度认知损害患者的静息态功能磁共振成像

识别轻度认知损害(mild cognitive impairment,MCI)的意义在于能尽早进行干预并推迟甚至阻止其进展为痴呆.不过,由于受到诊断方法和标准的限制,MCI患者的诊断较为困难.近年来,静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)作为一种新兴的功能影像学技术得到迅速发展,被广泛应用于MCI的研究,有可能为MCI的诊断提供客观的生物学标记物.文章就rs-fMRI在MCI中的研究进展进行了综述.     

Altered intrinsic regional brain activity in female asthmatics with or without depressive symptoms: A resting-state functional magnetic resonance imaging study

Background: Previous studies have suggested that asthma patients are more susceptible to anxiety or depression and have more specifically elevated depressive symptomology. These psychological factors are associated with anatomical brain changes. However, little is known about alterations in spontaneous brain activity in asthma patients with depressive symptoms. Here we hypothesized that asthma patients exhibit an altered regional spontaneous brain activity, which may contribute to their increased susceptibility to depression and poor perception of asthma symptoms. The purpose of this study was to examine spontaneous brain activity in female asthma patients using resting-state functional magnetic resonance imaging (rs-fMRI). Methods: Eleven asthmatics without depressive symptoms (ASs), 14 asthmatics with depressive symptoms (ADs), and 15 age- and education-matched healthy controls (HCs) completed rs-fMRI. The regional homogeneity (ReHo) value was calculated based on rs-fMRI to assess local signal synchrony strength and compared among the groups. Correlation analyses were conducted between both ReHo values and clinical parameters. Result: Compared with HCs, ASs showed a significantly increased ReHo in the right insula; whereas ADs showed a significantly decreased ReHo in the right insula, which positively correlated with nocturnal symptom score in the Asthma Control Test (r = 0.562, P = 0.036). No significant correlation was observed between the total ACT scores and right insula activities (r = 0.263, P = 0.364). Conclusion: Decreased ReHo in the right insula may play an important role in depressive symptoms and abnormal asthma symptom perception.     

Selective effects of methylphenidate in attention deficit hyperactivity disorder: A functional magnetic resonance study

Functional MRI revealed differences between children with Attention Deficit Hyperactivity Disorder (ADHD) and healthy controls in their frontal–striatal function and its modulation by methylphenidate during response inhibition. Children performed two go/no-go tasks with and without drug. ADHD children had impaired inhibitory control on both tasks. Off-drug frontal–striatal activation during response inhibition differed between ADHD and healthy children: ADHD children had greater frontal activation on one task and reduced striatal activation on the other task. Drug effects differed between ADHD and healthy children: The drug improved response inhibition in both groups on one task and only in ADHD children on the other task. The drug modulated brain activation during response inhibition on only one task: It increased frontal activation to an equal extent in both groups. In contrast, it increased striatal activation in ADHD children but reduced it in healthy children. These results suggest that ADHD is characterized by atypical frontal–striatal function and that methylphenidate affects striatal activation differently in ADHD than in healthy children.     

轻度认知障碍患者多模态磁共振特征

目的 探讨轻度认知损害者(MCI)和阿尔茨海默病(AD)患者多模态磁共振成像特征与认知功能的关系.方法 共纳入9例遗忘型MCI,15例轻度AD及11例正常对照,以简明精神状况检查(MMSE)和认知功能筛查测验(CASI)评估总体认知功能,对高分辨率结构像进行基于体素形态学分析(VBM),测量扩散张量成像(DTI)图像、各脑区白质各向异性比值(FA)和平均表观弥散系数(ADC),分析脑结构萎缩及白质DTI指标与认知评分的相关性.结果 MMSE和CASI评分与颞、额、顶、扣带回、海马旁回等结构灰质体积改变呈正相关(P<0.001),MMSE和CASI总分与颞、顶叶以及海马旁回的FA值呈正相关,与ADC值呈负相关(P<0.05).结论 MCI和AD患者认知功能与颞、顶、海马旁回等脑区萎缩及白质微观结构损伤密切相关,多模态影像技术可作为认知损害脑机制研究的重要技术手段.     

磁共振弥散张量成像与静息态功能磁共振成像联合应用对艾滋病患者轻度认知功能下降的初步研究

目的 应用磁共振弥散张量成像(DTI)与静息态功能磁共振成像(rs-fMRI)及两种图像融合技术探讨AIDS患者轻度认知功能下降白质损害与皮层功能区损害的分布及相互关系.方法 对26例经蒙特利尔认知评估量表(MoCA量表)评估的AIDS轻度认知功能下降患者(AIDS 组)和30名健康志愿者(健康对照组),行全脑DTI和rs-fMRI检查,获得全脑各向异性分数值(FA值)降低脑区分布图和以后扣带回为种子点静息态默认模式网络脑功能连接图,并采用图像融合技术将两组图像进行融合.结果 AIDS组脑白质FA值降低脑区为左楔前叶(t=4.0499,P＜0.005)和右侧的楔前叶(t=5.1553,P＜0.005)、额上回(t=5.1517、5.1484,均P＜0.005)、额中回(t=4.1444,P＜0.005)、中央前回(t=3.7395,P＜0.005)、枕叶(t=7.2236,P＜0.005)、顶下小叶(t=4.1450,P＜0.005);静息态与后扣带回功能连接相关脑区为左侧的扣带回(t=32.78,P＜0.005)、楔前叶(t=4.51,P＜0.005)、额上回(t=14.33、4.53,均P＜0.005)、颞中回(t=10.01、5.72,P＜0.005)、颞下回(t=5.99,P＜0.005)、海马旁回(t=7.63,P＜0.005)和右侧的后扣带回(t=34.81,P＜0.005)、楔前叶(t=32.09,P＜0.005)、额上回(t=14.12,P＜0.005)、额中回(t=17.71,P＜0.005)、颞上回(t=14.59,P＜0.005)和颞中回(t=11.83,P＜0.005);与后扣带回功能连接减弱相关脑区为左侧的楔前叶(t=5.39,P＜0.01)、前扣带回(t=3.66,P＜0.01)、小脑扁桃体(t=7.51,P＜0.01)和右侧的顶上小叶(t=4.44,P＜0.01)、海马旁回(t=3.69,P＜0.01)和小脑扁桃体(t=6.15,P＜0.01).图像融合分析显示,AIDS组左侧楔前叶脑白质FA值降低脑区其皮层功能活动显著减弱;左楔前叶、右侧的楔前叶、额上回、额中回FA值减低脑区其皮层功能活动受影响不大.结论 多个脑区脑白质神经纤维失连接和相关联皮层功能活动下降及代偿共同参与了AIDS轻度认知功能下降的发病过程.     

The value of cine nuclear magnetic resonance imaging for assessing regional ventricular function

Previous nuclear magnetic resonance (NMR) imaging studies to assess left ventricular function have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, an imaging approach using cine NMR and planes aligned with the true cardiac axes of the left ventricle was developed in views comparable with left ventricular cineangiography. Cine NMR imaging was used to assess regional wall motion and was validated by comparison with biplane left ventricular cineangiography. Fifty-nine patients underwent cineangiographic and NMR studies within 72 h. A poor quality NMR study precluded analysis in 4. leaving a study group of 55 patients (mean age 58 +/- 12: 17 women). Cine NMR movie loops were acquired in two long-axis planes: 1) right anterior oblique plane, parallel to the septum, and 2) four chamber orthogonal plane, perpendicular to the septum (this view is comparable to the angiographic left anterior oblique view). To assess regional wall motion, the left ventricle in both cine NMR and cineangiographic images was divided into five segments and graded on a five point grading scale from 3 for normal through 0 for akinesia and -1 for dyskinesia. Regional wall thickening was used qualitatively to aid in the analysis of wall motion. For the 275 segments compared in the right anterior oblique view, agreement was within one grade in 263 (95.6%) of 275 segments, whereas absolute agreement was observed in 171 (62%) of 275 segments. In the left anterior oblique view, of 200 segments evaluated, agreement within one grade was achieved in 184 segments (92%) and agreement was complete in 132 (66%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Brain magnetic resonance imaging abnormalities in patients with heart failure

BACKGROUND: Although heart failure (HF) is a common cardiovascular disorder, to date little research has been conducted into possible associations between HF and structural abnormalities of the brain. AIMS: To determine the frequency and pattern of magnetic resonance imaging (MRI) abnormalities in outpatients with chronic HF, and to identify any demographic and clinical correlates. METHODS: Brain MRI scans were compared between a sample of 58 HF patients, 48 controls diagnosed with cardiovascular disease uncomplicated by HF (cardiac controls) and 42 healthy controls. Deep, periventricular and total white matter hyperintensities (WMH), lacunar and cortical infarcts, global and medial temporal lobe atrophy (MTA) were investigated. RESULTS: Compared to cardiac and healthy controls, HF patients had significantly more WMH, lacunar infarcts and MTA, whereas cardiac controls only had more MTA, compared to healthy controls. Age and left ventricular ejection fraction (LVEF) were independently associated with total WMH. Age and systolic hypotension were associated with MTA in HF patients and cardiac controls. CONCLUSION: Our results suggest that cardiac dysfunction contributes independently to the development of cerebral MRI abnormalities in patients with HF. Age and low LVEF are the principal predictors of cerebral WMH in patients with HF and in cardiac controls.     

应用静息态功能磁共振技术研究针刺太溪穴对老年人脑网络的影响

目的采用无创的静息态功能磁共振技术,探讨真针刺和浅刺太溪穴对老年人脑网络的影响。方法选取老年人12名,在不同时间段分别真针刺和浅刺患者右侧太溪穴,针刺后用视觉模拟评分来评估受试者的针感强度。在针刺的前后分别采集功能性磁共振影像资料,分析脑网络连接变化。结果真针刺组较浅刺组酸、麻、胀、温热的感觉强度更大。真针刺组与浅刺组相比,海马与尾状核之间连接强度最大,其次为眼眶部前额叶皮质与海马之间的连接,以及大脑岛叶与壳核,颞中回与眼眶部前额叶皮质的网络连接较强。结论真针刺较浅刺组具有更强的针感,并且使大脑的网络连接的相互作用增强。     

Subclinical brain magnetic resonance imaging abnormalities predict physical functional decline in high-functioning older adults

OBJECTIVES: To determine whether severity of subclinical brain magnetic resonance imaging (MRI) abnormalities predicts incident self-reported physical impairment or rate of decline in motor performance. DESIGN: Longitudinal analysis, average follow-up time: 4.0 years. SETTING: Cardiovascular Health Study (CHS). PARTICIPANTS: CHS participants with modified Mini-Mental State Examination (3MS) score of 80 or greater, no self-reported disability, no history of stroke, and at least one assessment of mobility (n=2,450, mean age=74.4). MEASUREMENTS: Brain MRI abnormalities (ventricular enlargement, white matter hyperintensities, subcortical and basal ganglia small brain infarcts), self-reported physical impairment (difficulty walking half a mile or with one or more activities of daily living), and motor performance (gait speed, timed chair stand). RESULTS: After adjusting for demographics, cardiovascular risk factors, and diseases, risk of incident self-reported physical impairment was 35% greater for those with severe ventricular enlargement than for those with minimal ventricular enlargement, 22% greater for those with moderate white matter hyperintensities than for those with minimal white matter hyperintensities, and 26% greater for participants with at least one brain infarct than for those with no infarcts. Those with moderate to severe brain abnormalities experienced faster gait speed decline (0.02 m/s per year) than those with no MRI abnormalities (0.01 m/s per year). Further adjustment for incident stroke, incident dementia, and 3MS score did not substantially attenuate hazard ratios for incident self-reported physical impairment or coefficients for decline in gait speed. CONCLUSION: Subclinical structural brain abnormalities in high-functioning older adults can increase the risk of developing physical disabilities and declining in motor performance.     

Cerebral abnormalities in patients with cirrhosis detected by proton magnetic resonance spectroscopy and magnetic resonance imaging

Hepatic encephalopathy is a common problem in cirrhosis. The pathogenesis of this complication of advanced liver disease still remains unclear. Magnetic resonance spectroscopy was used to assess prospectively cerebral metabolism in 51 patients with histologically proven cirrhosis (Child-Pugh classes A, B, and C, 18, 18, and 15, respectively) and 36 healthy volunteers. According to the results of psychometric tests, overt hepatic encephalopathy, subclinical encephalopathy, and no encephalopathy were found in 14, 21, and 16 patients, respectively. Myoinositol/creatine ratios in gray (.36 +/- .17) and white (.35 +/- .22) matter voxel were reduced significantly (P < .0001) in cirrhotic patients compared with healthy volunteers (gray matter, .51 +/- .11; white matter, .64 +/- .16). In addition, patients showed a significant reduction (P = .024) in white matter choline/creatine ratio (.77 +/- .27) compared with controls (.92 +/- .25), and glutamine/glutamate level was elevated in cirrhotic patients compared with controls (gray matter, P < .0001; white matter, P = .036). Changes in cerebral myoinositol and glutamine/glutamate levels correlated significantly with the severity of hepatic encephalopathy (P < .0001). However, these metabolic alterations were also detected in patients without hepatic encephalopathy (normal psychometric test results). N-acetyl aspartate/creatine ratios did not differ between patients and controls. Magnetic resonance imaging detected bright basal ganglia in 37 patients, which correlated significantly with portal-systemic shunting and elevation of glutamine/glutamate, but not with the degree of hepatic encephalopathy. In conclusion, magnetic resonance imaging and spectroscopy showed that alterations of cerebral metabolism are common in patients with cirrhosis, even without evidence of clinical or subclinical hepatic encephalopathy.(Hepatology 1997 Jan;25(1):48-54)     

The characteristic of fractional amplitude of low frequency fluctuation in depression patients with suicidal ideation:a resting-state functional magnetic resonance imaging study

正Objective To explore the characteristic of fractional amplitude of low frequency fluctuation(fA LFF)and the relationship with the severity of depression,suicidal ideation and suicide risk in depression patients with suicidal ideation with resting-state functional magnetic resonance imaging(rs-fM R).;Methods Resting state functional     

血氧水平依赖功能磁共振成像在血管性认知损害诊断中的应用

血管性认知损害（vascularcognitiveimpairment,VCI）诊断的意义在于能早期干预并推迟甚至阻止其进展。不过,由于受到诊断方法和标准的限制,轻度VCI患者往往不能得到及时而准确的诊断。最近的研究显示,血氧水平依赖功能磁共振成像（blood oxygen level dependent functional magnetic resonance imaging, BOLD-fMRI）有可能为VCI的诊断提供客观指标。文章就BOLD-fMRI在VC I诊断中的应用进行了综述。     

Comparison of magnetic resonance real-time imaging of left ventricular function with conventional magnetic resonance imaging and echocardiography

This study analyzes the accuracy of a new real-time magnetic resonance imaging (MRI) technique (acquisition duration, 62 ms/image) and echocardiography for the determination of left ventricular (LV) end-diastolic volume, end-systolic volume, ejection fraction, and muscle mass when compared with turbo gradient echo imaging as the reference standard. Thirty-four patients were examined with digital echocardiography, standard, and real-time MRI. A close correlation was found between the results of real-time imaging and the reference standard for end-diastolic volume, end-systolic volume, and ejection fraction (r >0.95), with a lower correlation for LV muscle mass (r = 0.81). Correlations between echocardiography and the reference standard were lower for all parameters. Real-time MRI enables the acquisition of high-quality cine loops of the entire heart in minimal time without electrocardiographic triggering or breath holding. Thus, patient setup and scan time can be reduced considerably. Results are similar to the reference standard and superior to echocardiography for determining LV volumes and ejection fraction. This technique is a valid alternative to current approaches and can form the basis of every cardiac MRI examination.     

Delayed contrast-enhanced magnetic resonance imaging for the prediction of regional functional improvement after acute myocardial infarction

OBJECTIVES: We evaluated whether delayed contrast-enhanced magnetic resonance imaging (DCE-MRI) using an extracellular contrast agent could predict improvement of dysfunctional but viable myocardium after acute reperfused myocardial infarction (MI). BACKGROUND: The transmural extent of hyperenhancement at DCE-MRI has been related to improvement of function in reperfused MI. However, evidence is still limited, and earlier reports have produced conflicting results regarding the significance of contrast patterns after infarction. METHODS: Thirty patients (mean age 59 +/- 11 years, 27 males) underwent cine MRI and DCE-MRI 7 +/- 3 days after a first reperfused acute MI and follow-up cine MRI at 13 +/- 3 weeks. Segmental wall thickening and segmental extent of hyperenhancement were scored in 1,689 segments. RESULTS: Of 500 dysfunctional segments, 273 (55%) improved at follow-up. There was no difference in likelihood of improvement or complete functional recovery between segments with 0% and 1% to 25% hyperenhancement. The likelihood of improvement of segments without hyperenhancement was 2.9, 14.3, and 20 times higher than that of segments with 26% to 50%, 51% to 75%, and >75% hyperenhancement, respectively (p < 0.001). The likelihood of complete functional recovery of segments without hyperenhancement was 3.8, 11.1, and 50 times higher than that of segments with 26% to 50%, 51% to 75%, and >75% hyperenhancement, respectively (p < 0.001). CONCLUSIONS: In patients with recent reperfused MI, functional improvement of stunned myocardium is predicted by DCE-MRI.     

Use of muscle functional magnetic resonance imaging with older individuals

Muscle functional magnetic resonance imaging (mfMRI) has been widely used to study muscle recruitment in exercise in young healthy subjects, but has not been validated or used with older subjects. This study validates and demonstrates the use of mfMRI in older subjects. Subjects consisted of apparently healthy sedentary younger (n = 7) and older (n = 6) women. Proton transverse relaxation (T2)-weighted MRI scans were obtained of the quadriceps femoris at rest and immediately following three bouts of knee extension exercise (50%, 75%, and 100% of untrained 5 x 10 repetition maximum [RM]). Older subjects performed knee extension training for 12 weeks and repeated the MRI scan protocol using the same absolute loads. Training induced a 13% increase in 1 RM and a 25% increase in 5 x 10 RM. Older subjects had higher resting T2 values compared with younger subjects; however, the T2 response to exercise (slope) was similar among groups (young = 0.063+/-0.003, older untrained = 0.055+/-0.011, older trained = 0.053+/-0.008; p > .05). In all cases, T2 increased linearly with load. Trained older subjects showed a lower T2 response when lifting the same absolute load compared with before training, which is consistent with results previously obtained from young subjects. In the older population, mfMRI is appropriate for use and offers benefits over other technologies.     

肝纤维化的MR功能成像研究

长期以来,临床多以肝活检组织病理学检查作为诊断肝纤维化的金标准,但其有一定的创伤性及盲目性。MR功能成像研究如MR灌注成像、MR弥散成像、MR波谱分析、磁化传递对比、磁共振弹性成像在肝纤维化、肝硬化的诊断、治疗及预后的评价方面发挥着重要的作用,它们各具优缺点,应进行合理的选用及相互对照验证。     

慢性肾脏病3~4期患者认知功能损害的脑静息态功能磁共振研究

目的 观察慢性肾脏病(CKD)患者认知功能水平与脑功能的改变。方法 选择2018年1月至2020年 1月在东直门医院被诊断为CKD 3~4期的10 例患者为观察组,同时纳入19例肾功能正常的受试者作为对照组。分别进行简明精神状态量表(MMSE)、听觉词语学习测验量表(AVLT)、数字广度(DST)、动物词语流畅性量表(AFT)、形状连线测试A和B(TMT A and B)和高山量表评价2组受试者的认知功能和对记忆的满意程度,并进行静息态功能磁共振扫描观察2组受试者脑功能的差异。临床数据采用SPSS 20.0统计软件处理。 结果 在认知功能方面,与对照组相比,观察组AVLT的即刻回忆、短延时回忆和长延时回忆得分均显著下降(P＜0.005),高山量表评分显著降低(P=0.024)。在脑功能方面,观察组左侧海马度中心度值(DC)较对照组显著增加(P＜0.01);左侧海马与额中回和中央前回的功能连接减弱(P＜0.01),并且这种功能连接减弱与听觉短延时回忆和长延时回忆呈显著负相关(P＜0.05)。结论 CKD患者较肾功能正常的受试者认知功能水平有所下降,尤其是情景记忆功能;在脑功能方面,CKD患者的海马DC值增加,海马与额中回和中央前回的功能连接减弱,且这种功能连接减弱与情景记忆功能呈显著负相关。