超声应变率显像在心功能检测中的应用

超声应变率显像是基于组织多普勒显像的一种新技术,它能够评价心肌的收缩、舒张功能,这不仅体现在该技术能够评估心脏整体功能,而且它更主要应用于评估心室局部功能,因此它在室壁心肌缺血的早期检出、心脏负荷试验中具有重要意义。另外,超声应变率显像还能够定量估测心肌病的心脏收缩、舒张功能,这有助于对限制型心肌病和缩窄性心包炎的鉴别。本文还简单地阐述了超声应变率显像的技术特点、判定标准以及该技术尚存在的缺陷。     

组织多普勒技术评价扩张型心肌病左室心功能的临床价值

目的探讨组织多普勒技术(TDI)检测扩张型心肌病(DCM)左室心功能的临床价值。方法选择DCM病人和正常健康者各40例,用TDI于胸骨旁长轴检测室间隔及左室后壁中间段短轴方向心肌运动速度(MV),并计算心肌运动速度阶差(MVG);经心尖窗检测左室前壁、后壁、下壁、侧壁和前壁、后壁室间隔中间段长轴方向MV。结果DCM组病人出现4种MV频谱形态异常,长轴、短轴方向MV均明显低于正常对照组(P<0.05或P<0.01);DCM组MVG也明显低于正常对照组(P<0.05或P<0.01)。结论TDI可定量评价DCM病人左室心肌功能,丰富了DCM的超声诊断手段。     

彩色多普勒能量图对慢性肾功能不全患者肾血流动力学研究

应用彩色多普勒能量图(CDEI)研究慢性肾功能不全肾血流分布、频谱特征及血流参数检测,旨在对临床医生分析病情、疗效及预后提供参考及疾病鉴别.方法 检测30例正常组和60例肾功能不全的肾脏,根据肾内血管显像水平,将CDEI分为四型.结果 慢性肾功能不全主肾动脉及分支血流信号分布有逐渐减弱甚至消失.肾动脉血流参数表明,从主肾动脉及分支血流速度逐渐明显降低,阻力指数较大,搏动指数增大.结论 本组结果表明,慢性肾功能不全患者,肾动脉分支血流分布,频谱特征及血流信号的分布,频谱形态的变化特征及血流参数的异常,可初步判断肾血流及肾功能状态,迅速了解病情、监测治疗、评估预后,为临床医生提供更加完善的依据.     

Myocardial Perfusion SPECT Imaging in Patients after Percutaneous Coronary Intervention

Coronary artery disease (CAD) is the most prevalent form of cardiovascular disease affecting about 13 million Americans, while more than one million percutaneous transluminal intervention (PCI) procedures are performed annually in the USA. The relative high occurrence of restenosis, despite stent implementation, seems to be the primary limitation of PCI. Over the last decades, single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), has proven an invaluable tool for the diagnosis of CAD and patients' risk stratification, providing useful information regarding the decision about revascularization and is well suited to assess patients after intervention. Information gained from post-intervention MPI is crucial to differentiate patients with angina from those with exo-cardiac chest pain syndromes, to assess peri-intervention myocardial damage, to predict-detect restenosis after PCI, to detect CAD progression in non-revascularized vessels, to evaluate the effects of intervention if required for occupational reasons and to evaluate patients' long-term prognosis. On the other hand, chest pain and exercise electrocardiography are largely unhelpful in identifying patients at risk after PCI.Although there are enough published data demonstrating the value of myocardial perfusion SPECT imaging in patients after PCI, there is still debate on whether or not these tests should be performed routinely.     

Imaging of Language-Related Brain Regions in Detoxified Alcoholics

Background:  Neuroimaging studies showed clear evidence of alcoholism-related damage to the frontal lobes and cerebellum. Although these regions have been involved in language processing, language skills are relatively spared in alcoholics. Here, we aimed at identifying neural substrates associated with the preserved mechanisms of language processing in alcoholics. We hypothesized that alcoholics would show a different pattern of neural activity compared with the controls.
Methods:  Alcoholic and nonalcoholic subjects performed an auditory language task while receiving a functional magnetic resonance imaging (fMRI) scan in a 1.5 T magnet. This task has been previously shown to solicit the comprehension processing in healthy controls, with reliable fMRI response in the left frontal and temporal/parietal lobes.
Results:  Behavioral results showed comparable performance (error rates, response time) between the alcoholics and the matched controls. However, analysis of the functional data revealed that the alcoholics exhibited greater fMRI response in the left middle frontal gyrus (pars triangularis), the right superior frontal gyrus, and the cerebellar vermis relative to the controls.
Conclusions:  These findings suggest that frontocerebellar neural activity, supporting the comprehension processing of the auditory language task, may require compensatory mechanisms in alcoholics in order to maintain the same level of performance as the controls.     

组织多普勒成像估测主动脉瓣狭窄患者左心室长轴收缩功能

目的:观测主动脉瓣狭窄患者左心室长轴收缩功能的变化,并探讨其临床意义.方法:选择主动脉瓣狭窄患者40例,根据主动脉瓣口有效面积大小,将主动脉瓣狭窄患者分为轻度狭窄组13例、中度狭窄组14例和重度狭窄组13例,正常对照组16例(健康志愿者).应用组织多普勒成像技术测定二尖瓣环的左心室长轴收缩期峰值运动速度(SM)和收缩期二尖瓣环位移(DS).结果:正常对照组及主动脉瓣狭窄各组SM、DS呈现逐渐减低的显著性变化(分别F=56.7,P＜0.0001;F=92.9,P＜0.0001).SM和DS在狭窄各组与正常对照组之间以及狭窄各组之间均存在显著性差异(P均＜0.01).结论:主动脉瓣狭窄患者的左心室长轴收缩功能受损出现在左心室短轴收缩功能减低之前,并且随着主动脉瓣狭窄程度的增加而恶化.     

脑钠素与心功能

脑钠素 (BNP)是继心钠素 (ANP)后利钠肽系统的又一成员 ,由于它首先是由日本学者 Sudoh等于1988年从猪脑分离出来的因而得名 [1] ,而实际上它主要来源于心室。 BNP具有重要的病理生理学意义 ,它可以促进排钠、排尿 ,具较强的舒张血管作用 ,可对抗肾素 -血管紧张素 -醛固酮系统的缩血管作用 ,同 ANP一样是人体抵御容量负荷过重及高血压的一个主要工具。心功能障碍能够极大地激活利钠肽系统 ,心室负荷增加导致 BNP释放。1　 BNP的生成、代谢与测定1.1　 BNP的结构、合成与分泌 :BNP具有种属特异性 ,大鼠的 BNP由 4 5个氨基酸组成 …     

脑源性神经营养因子与脑功能

脑源性神经营养因子是首先在猪脑中发现的一种具有神经营养作用的蛋白质。脑源性神经营养因子及其受体在神经系统广泛表达。根据近几年对脑源性神经营养因子和脑功能的研究,本文就脑源性神经营养因子在学习与记忆、突触可塑性、神经保护和神经精神系统疾病等方面所发挥的作用作一综述。     

星形细胞在脑损伤中的双向作用

脑损伤后星形细胞会大量增生 ,这些反应性星形细胞可减轻兴奋性氨基酸毒性的损伤 ,缓冲K+ H+ 离子 ,减轻传递抑制 ,对抗氧化损伤和乳酸堆积 ,从而发挥有益的作用。同时 ,这些反应性星形细胞可能参与了脑损伤后的炎症级联反应 ,引起继发性损伤 ,大量增生的星形胶质成为轴突再生和突触重建的障碍 ,从而影响脑损伤后的功能恢复。     

SPECT脑血流灌注显像在脑动静脉畸形中的应用

文章回顾了单光子发射计算机体层摄影术 (SPECT)脑血流灌注显像技术的发展及其影像特征 ,并对应用SPECT研究脑动静脉畸形 (AVM)与盗血、术后出血的关系、AVM与癫的关系以及癫灶的定位、功能区AVM的定位、术后复查和随访方法等作了介绍。     

Role of Functional Brain Imaging in Understanding Rheumatic Pain

Rheumatic pain and, in particular, rheumatoid arthritis, osteoarthritis and fibromyalgia, are common and debilitating chronic pain syndromes. Recently, human functional neuroimaging, for example EEG, fMRI, and PET has begun to reveal some of the crucial central nervous system mechanisms underlying these diseases. The purpose of this review is to summarise current knowledge on the brain mechanisms of rheumatic pain revealed by functional neuroimaging techniques. The evidence suggests that two mechanisms may be largely responsible for the clinical pain associated with these rheumatic diseases: abnormalities in the medial pain system and/or central nervous system sensitisation and inhibition. If we can understand how functioning of the central nociceptive system becomes altered, even in the absence of peripheral nociceptive input, by using functional neuroimaging techniques, in the future we may be able to develop improved, more effective treatments for patients with chronic rheumatic pain.     

Evaluation of Right Ventricular Function by Using Tissue Doppler Imaging in Patients after Repair of Tetralogy of Fallot

Background: The aim of this study was to assess the relation between plasma B-type natriuretic peptide (BNP) levels and right ventricular function evaluated by tissue Doppler imaging (TDI) in patients after repair of tetralogy of Fallot (ToF). Methods: Twenty-five patients with a mean age of 14.1 ± 4.4 years who underwent repair of ToF at a mean age of 4.9 ± 5.1 years enrolled in this study. The control group consisted of 29 healthy children at a mean age of 13.1 ± 2.8 years. The right ventricle and pulmonary regurgitation (PR) were assessed by two-dimensional echocardiography and color Doppler. Blood samples for BNP levels were taken and TDI was performed at rest. Results: Plasma BNP levels were significantly higher in patients than in controls (28.3 ± 24.1 vs. 7.4 ± 2.3 pg/mL, P = 0.0001). The myocardial performance index (MPI) (1.08 ± 0.35 vs. 0.58 ± 0.11, P = 0.0001) was higher and isovolumic acceleration (IVA) (3.1 ± 0.7 vs. 5.4 ± 1.0 m/s², P = 0.0001) was lower in patients. The correlations were also significant between the degree of PR and MPI (r = 0.7, P = 0.0001) and also IVA (r =−0.7, P = 0.0001). The correlations were also significant between the BNP level and MPI (r = 0.6, P = 0.0001), IVA (r =−0.4, P = 0.002) and the degree of PR (r = 0.6, P = 0.0001) . Conclusion: As a result, plasma BNP level increases in patients with ToF and both MPI and IVA from the right ventricular basal segments might be used to assess the right ventricular function .     

改良的迭代图像重建法在单光子发射计算机断层心肌灌注显像的临床应用研究

目的:以滤波反投影重建法(FBP)为标准,评价改良的迭代图像重建方法(Astonish,AS),在单光子发射计算机断层(SPECT)心肌灌注显像的临床应用研究。方法:100例疑诊或确诊冠心病患者行SPECT心肌显像。根据注射显像剂的用量,分为全剂量组(n=54)和半剂量组(n=46)。全剂量组:两日法门控运动+静息心肌灌注显像,运动和静息显像均先行半时间采集,随后全时间采集,半时间用AS重建,全时间用FBP重建;半剂量组:一日法门控运动+静息心肌灌注显像,运动时注射99m锝—甲氧基异丁基异腈[99mTc-MIBI(5.2±0.6)mCi,标准一日法剂量的一半],先行全时间采集,随后双倍时间采集,全时间用AS重建,双倍时间用FBP重建;如果运动显像异常,于当日行静息显像(与全剂量组静息显像完全相同)。用4分法对图像质量进行半定量评分(1:差,2:一般,3:好,4:非常好)。图像诊断结果采用5分类法(正常,心肌梗死,心肌缺血,心肌缺血+心肌梗死,模棱两可)。结果:两组中图像质量评分AS图像均高于FBP图像(P<0.001)。诊断结果按照5分类法,AS图像与FBP图像之间有高度的诊断一致性(Kappa=0.922,P<0.001)。结论:经AS重建的半时间采集或半剂量注射的心肌灌注图像,其质量优于全时间和全剂量标准的FBP重建的图像,但不影响对诊断结果的判断。     

Functional Imaging of the Brain in Patients with Liver Cirrhosis

Brain imaging techniques have provided substantial insight into the pathophysiology of hepatic encephalopathy (HE). Magnetic resonance imaging gave hint to the fact that there is an increased deposition of manganese especially in the basal ganglia. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) showed that the preference of the basal ganglia might be due to differences in regional cerebral blood flow and an additional redistribution of blood flow from the cortex to subcortical regions in cirrhotics. PET studies using ammonia as tracer showed that the cerebral metabolism of ammonia and the permeability of the blood brain barrier for ammonia is increased in cirrhotic patients compared to healthy controls. The regional ammonia supply is in accordance with the regional blood flow. In accordance with these findings fluorodesoxyglucose-PET-studies of the brain in cirrhotics showed characteristic alterations of glucose utilisation in the patients with a relative decrease of the glucose utilisation of the cingulate gyrus, the frontomedial, frontolateral, and parieto-occipital cortex, while the glucose utilisation of the basal ganglia, the hippocampus, and the cerebellum was relatively increased. These findings fit well with the clinical characteristics of early stages of HE such as deficits in attention, visuo-spatial orientation, visuo-constructive abilities, motor speed, and accuracy.