GE0.35T磁共振脑功能成像在急性缺血性脑血管病的临床应用思路构建

目的探讨GE0.35T磁共振脑功能成像在急性缺血性脑血管病的临床应用。方法对我院2009年5月~2010年5月收治的180例急性缺血性脑血管病患者进行MRI、DWI和PWI扫描。结果在180例患者中,有20例属于短暂性脑缺血发作,有160例属于急性的脑梗死。在这160例的急性脑梗死患者中,有120例患者是在6h内发作的,还有40例患者则是在6~12h发病的。在6h以内发病的120例患者中的,PWI扫描结果大于DWI扫描结果的有54例,PWI扫描结果和DWI扫描结果相等的有0例。在6~12h之间发病的40例患者中,有24例PWI扫描结果大于DWI扫描结果,还有8例PWI扫描结果和DWI扫描结果相等。结论 GE0.35T磁共振脑功能成像是一种能明显提高急性缺血性脑血管病变显示率的简便方法,值得进行临床推广。     

首发抑郁症伴自杀意念患者中缝核功能连接的改变

目的 观察首发抑郁症伴自杀意念（SI）患者中缝核功能连接（FC）改变。方法 前瞻性纳入98例首发抑郁症患者,根据伴SI与否将其分为伴SI组（n=56）与不伴SI组（n=42）;另以47名健康志愿者为对照组。以静息态功能MRI观察背侧中缝核（DRN）、中缝中央核（MRN）与全脑间的FC;比较3组及两两组间FC,分析伴SI组差异脑区FC与临床资料的相关性。结果 相比对照组,伴与不伴SI组DRN与左侧小脑及左侧壳核的FC均降低（P均<0.05）,MRN与右侧颞下回的FC均升高而与左侧额下回、右侧枕上回、左侧顶下小叶及左侧壳核的FC均降低（P均<0.05）;其中,伴SI组DRN与左侧壳核的FC高于不伴SI组（P<0.05）;相比不伴SI组及对照组,伴SI组MRN与右侧中央后回的FC升高（P均<0.05）。伴SI组MRN与左侧壳核的FC与24项汉密尔顿抑郁量表（HAMD-24）体质量得分呈正相关（r_s=0.297,P=0.026）。结论 首发抑郁症伴SI患者中缝核与皮层和皮层下区的FC存在异常改变,且其MRN与左侧壳核的FC与HAMD-24体质量得分呈正相关。     

多模态MRI技术评估脑老化及脑老化与脑疾病的关系研究进展

人类脑随年龄增长而退化,即脑老化;其过程与认知能力下降趋势一致,即神经退行性疾病发病风险随年龄增长而逐渐增加。加强对脑老化的认识并筛选相关生物标志物,对于早期诊断神经退行性疾病、预测年龄相关认知能力下降至关重要。本文对多模态MRI技术用于评估脑老化及脑老化与脑疾病关系的研究进展进行综述。     

术前功能磁共振在脑功能区肿瘤切除中的应用

目的探讨术前功能磁共振（fMRI）在功能区肿瘤切除中的临床应用价值。方法10例肿瘤邻近脑运动功能区患者，平均51．3岁，7例肢体无力，2例抽搐，1例口角偏斜，术前Karnofsky评分平均82分。常规行头颅核磁增强扫描，证实肿瘤位于功能区，再行fMRI检查。依据fMRI中活化区与肿瘤的位置关系决定全切或者次全切除肿瘤，术中避免活化区的损伤。术后观察肢体肌力恢复情况、进行术后Karnofsky评分并复查核磁了解术后肿瘤切除情况，与术前进行对比。结果10例fMRI活化区显示清晰，8例活化区被肿瘤挤压移位，拉伸变形。肿瘤边缘与活化区的最近距离0～26mm，平均13．6mm。本组肿瘤全切7例，次全切除3例。术后肌力好转7例，2例抽搐患者术后未再出现抽搐；1例口角歪斜患者术后面神经功能分级减轻。术后1个月Karnofsky评分平均93分。术后1周复查MRI显示：肿瘤消失7例，余3例肿瘤缩小95％～99％。结论fMRI对邻近脑运动功能区肿瘤患者的术前评价有重要临床意义，对手术切除脑功能区周围肿瘤并保留运动功能有重要的指导作用。     

应用脑功能磁共振成像及弥散张量成像技术辅助切除脑运动区皮层深部区域的胶质瘤

对于累及脑中央前回深部及其邻近部位的胶质瘤，手术切除的严重并发症是永久性的运动功能丧失。如何在保护脑功能的前提下尽可能彻底地切除肿瘤，一直是人们努力的方向。     

ASL脑灌注成像的应用

ASL(arterial spin labeling)即动脉自旋标记技术，是一种以可自由弥散的水为内在示踪剂的MR灌注成像方法，它利用反转脉冲标记上游动脉血中的水质子，将下游成像层所获标记图像与没有标记的对照组减影而获得器官的血流量。十多年来，ASL已经在人类和动物身上的多种病理、生理情况下证明了其价值。本文综述其近年来的主要应用情况。     

短暂性脑缺血脑默认状态网络的功能磁共振研究

目的利用fMRI研究TIA患者脑默认状态网络的变化。方法分别采集16例TIA发作间期患者和16名止常对照组静息态fMRI扫描,以扣带回／楔前叶及腹侧扣带前回／内侧前额叶作为种子点,分析与种子点连通的脑区,研究两组间默认状态网络的变化。结果TIA组与正常组具有相似脑默认状态网络,TIA组与正常组比较,ROI功能连接减弱的脑区域包括：扣带前回、楔前叶、前额叶及海马等脑区,功能连接增强的区域主要存在小脑及丘脯。结论TIA患者脑默认状态网络存在异常,扣带回、楔前叶及海马等脑区连通性的减弱反应TIA患者脑DMN失衡,丘脑和小脑的连通性增姒,可能是脑TIA局部脑区功能减弱的补偿及保护性反应。     

丙泊酚人脑中枢作用部位的功能磁共振成像分析

目的应用功能磁共振成像技术（fMRI）研究丙泊酚对健康志愿者脑不同部位功能变化的影响,探索丙泊酚在脑内的可能作用部位。方法采用丙泊酚静脉麻醉的刺激程序：清醒-镇静-意识消失-苏醒的动态过程,丙泊酚麻醉按1．5mg／kg通过恒速泵静脉注射,注射时间均为90s。采用1．5T Philips Gyroscan磁共振系统,运用单次激发平面回波序列（EPI）扫描序列进行脑功能血氧水平依赖（BOI．D）法成像并应用Functool软件进行功能分析。结果丙泊酚麻醉可抑制下丘脑磁共振信号,r值为0．75,信号变化强度为（20．2±11．6）％;可降低额叶信号,r值为0．71,信号降低强度为（37．5±16．7）0A;颞叶信号也受到抑制,r值为0．72,信号变化强度为（33．8±10．4）％。三个部位信号的抑制呈爆发性,变化过程同步,信号降低强度额叶〉颞叶〉下丘脑,但三者间差异无统计学意义。丘脑部位信号也明显降低,r值为0．60,信号变化强度为（3．9±1．6）％,与额叶、颞叶、下丘脑相比,差异均有统计学意义（P〈0．05）。结论丙泊酚麻醉首先抑制下丘脑、额叶、颞叶区域,随后丘脑区域受到抑制,这些区域可能是丙泊酚麻醉作用的靶位。     

脊髓型多发性硬化患者默认网络及突显网络的功能连接

目的采用独立成分分析(ICA)方法分析脊髓型多发性硬化(SMS)患者脑静息态默认网络(DMN)及突显网络(SN)功能连接(FC)的异常。方法对我院22例SMS患者(SMS组)及22名健康对照者(正常对照组)行静息态fMRI,对所得数据进行ICA分析,并利用SPM8比较两组脑网络FC的差异,同时分析差异脑区的时间序列信号(FC分数)与临床扩展残疾状态量表(EDSS)评分及病程的相关性。结果与正常对照组相比,SMS组DMN的FC减弱的脑区包括双侧内侧额上回、边缘叶及双侧楔叶,FC增强的脑区包括双侧前扣带回、右侧距状皮层;SMS组SN的FC减弱的脑区为双侧内侧扣带回,FC增强的脑区延伸到双侧中央前回、左侧中央后回。两组FC分数与EDSS评分及病程均无相关性(P均0.05)。结论 SMS患者静息态DMN、SN均存在FC异常,可能与继发于脊髓病变的逆行性神经元变性或功能网络重构有关。     

意识与脑功能连接性:麻醉药物作用机制的研究进展

背景 功能连接性(整合),相对于解剖结构连接性,是指在耦联的神经系统中信号之间存在统计学上的依赖关系,近年来发现大脑不同区域之间的功能连接性与意识关系密切,而麻醉药物诱导意识丧失的机制很可能与功能连接性有关.目的 现从意识与大脑功能连接性角度对麻醉药物作用机制的研究进展作一综述.内容 静息态功能磁共振(resting state functional magnetic resonance imaging,rs-fMRI)在分析大脑功能连接性方面具有优势,多项研究应用rs-fMRI技术分析全身麻醉药物对脑区功能连接性的影响,提示麻醉药物的可能作用靶点为脑区功能连接性. 趋向 rs-fMRI技术的不断发展,为研究麻醉药物作用机制开辟了新的方向.     

功能MRI评估2型糖尿病早期肾损害研究进展

糖尿病肾病（DKD）是糖尿病微血管并发症,亦为导致终末期肾脏病的主要原因。早期诊断、及时干预可有效控制DKD病情进展并改善预后。近年来,功能MRI （fMRI）逐渐用于定量评估2型糖尿病（T2DM）患者早期肾损害。本文就fMRI评估T2DM早期肾损害研究进展进行综述。     

定量MRI用于强直性脊柱炎研究进展

强直性脊柱炎(AS)是免疫介导的慢性炎性关节炎,早期诊断及治疗可控制病情进展和改善预后。根据定量MRI技术各参数值可定量观察AS患者骶髂关节(SIJ)特定物质含量及结构变化,为早期诊断AS及评价治疗效果提供更准确的信息。本文对定量MRI用于AS的研究进展进行综述。     

MR引导下乳腺穿刺活检机器人研究进展

乳腺癌是目前发病率最高的恶性肿瘤之一。早期诊断及治疗乳腺癌对改善预后具有重要意义。随着机器人技术发展成熟,MR引导下乳腺穿刺活检机器人技术可能成为早期诊治乳腺癌的理想方式之一。本文对近年来MR引导下乳腺穿刺活检机器人研发及应用进展进行综述。     

Large-scale functional connectivity predicts cognitive impairment related to type 2 diabetes mellitus

BACKGROUNDLarge-scale functional connectivity (LSFC) patterns in the brain have unique intrinsic characteristics. Abnormal LSFC patterns have been found in patients with dementia, as well as in those with mild cognitive impairment (MCI), and these patterns predicted their cognitive performance. It has been reported that patients with type 2 diabetes mellitus (T2DM) may develop MCI that could progress to dementia. We investigated whether we could adopt LSFC patterns as discriminative features to predict the cognitive function of patients with T2DM, using connectome-based predictive modeling (CPM) and a support vector machine.AIMTo investigate the utility of LSFC for predicting cognitive impairment related to T2DM more accurately and reliably.METHODSResting-state functional magnetic resonance images were derived from 42 patients with T2DM and 24 healthy controls. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Patients with T2DM were divided into two groups, according to the presence (T2DM-C; n = 16) or absence (T2DM-NC; n = 26) of MCI. Brain regions were marked using Harvard Oxford (HOA-112), automated anatomical labeling (AAL-116), and 264-region functional (Power-264) atlases. LSFC biomarkers for predicting MoCA scores were identified using a new CPM technique. Subsequently, we used a support vector machine based on LSFC patterns for among-group differentiation. The area under the receiver operating characteristic curve determined the appearance of the classification.RESULTSCPM could predict the MoCA scores in patients with T2DM (Pearson’s correlation coefficient between predicted and actual MoCA scores, r = 0.32, P=0.0066 [HOA-112 atlas]; r = 0.32, P=0.0078 [AAL-116 atlas]; r = 0.42, P=0.0038 [Power-264 atlas]), indicating that LSFC patterns represent cognition-level measures in these patients. Positive (anti-correlated) LSFC networks based on the Power-264 atlas showed the best predictive performance; moreover, we observed new brain regions of interest associated with T2DM-related cognition. The area under the receiver operating characteristic curve values (T2DM-NC group vs. T2DM-C group) were 0.65-0.70, with LSFC matrices based on HOA-112 and Power-264 atlases having the highest value (0.70). Most discriminative and attractive LSFCs were related to the default mode network, limbic system, and basal ganglia.CONCLUSIONLSFC provides neuroimaging-based information that may be useful in detecting MCI early and accurately in patients with T2DM.     

Evaluation of changes in motor and visual functional activation over time following moderate-to-severe brain injury

Primary objective: Relatively little research has documented functional recovery following traumatic brain injury using neuroimaging techniques. This study aimed to examine the effects of moderate-to-severe brain injury on brain functioning over time.

Research design: Eight brain-injured participants completed motor and visual tasks during fMRI at two time points within the first year following injury. Changes in functional activation within ROIs and in dispersion of activation were evaluated across time points.

Main outcomes and results: Participants demonstrated significantly reduced activation intensity within the ROI over time for the motor task, but not the RPS task. Participants demonstrated a (non-significant) trend toward reduced functional dispersion over time. Most participants demonstrated greater activation within (vs outside) the ROI for both tasks. Variability among participants, in terms of activation intensity and dispersion, was evident.

Conclusions: The findings provide support for the occurrence of functional recovery over the first year post-injury, with fewer resources utilized during task completion over time. Additionally, results suggest that variability in functional activation and activation in brain regions typically activated among controls could be anticipated in a moderate-severe TBI group. Lastly, simple motor and visual tasks may be useful in efforts to demonstrate functional recovery over time.