冠心病的心肌超声造影

目的 探索心肌超声造影（MCE）在可疑冠心病及冠心病中的应用.方法 43例患者进行了超声心动图检查,并在静息状态下行心肌声学造影.造影图像采用ACQ软件对微泡再充盈曲线进行定性及定量分析.结果 43例患者中有60个节段显示灌注异常,冠脉造影正常者中有4个节段灌注减弱,定性分析和定量分析基本一致.结论 心肌超声造影有望成为可疑冠心病及冠心病的常规检查方法.     

心肌造影检测冠状动脉微循环内皮损伤的初步应用研究

目的：探讨心肌超声造影（Myocardial contrast echocardiography, MCE）在检测冠心病早期冠脉微循环内皮损伤中的应用价值。资料与方法：选择冠状动脉造影（Coronary angiography, CAG）检查结果正常的患者20例为冠心病高危人群组（第2组）,另选年龄匹配的健康志愿者20例作对照组（第1组）行“声诺维”心肌造影。造影后进行4次闪烁成像,分析两组闪烁显像后心肌血流再灌注充盈曲线,获得再充盈峰值强度（PI）、达峰值强度时间（TP）以及心肌内微泡持续显影时间（T）并作定量分析。结果：第2组4次flash后的峰值强度均低于对照组（P<0.05）,达峰值强度时间（TP）以及心肌内微泡持续显影时间均明显大于对照组（P<0.05）。结论：MCE通过定量评价心肌微循环灌注可达到检测冠状动脉微循环内皮功能损伤的目的。     

心肌声学造影评价硝酸甘油对犬心肌缺血再灌注损伤的延迟保护作用

目的　探讨心肌声学造影 (myocardial contrastechocardiography,MCE)技术评价硝酸甘油对犬心肌缺血再灌注损伤的延迟保护作用的价值。方法　 12只健康成年杂种犬随机分成缺血再灌注组和硝酸甘油组 ,缺血再灌注组不给予任何药物 ,保持基础状态 ,单纯给与左冠状动脉前降支结扎 180 min,再灌注 12 0 min,在持续缺血和再灌注阶段行心肌声学造影 ,硝酸甘油组 ,用微量静脉泵以 2μg/(kg· min)速度静滴硝酸甘油 1h,2 4 h后结扎左冠状动脉前降支 ,其余步骤同缺血再灌注组。于左室乳头肌水平测定正常灌注区与缺血低灌注区心肌视频密度时间 -强度曲线参数 ,及缺血和再灌注阶段左室壁造影剂显影缺损区 (分别代表心肌危险区面积和坏死区面积 ) ,并与伊文思蓝及红四氮唑 (triphenyl tetrazolium chloride,TTC)心肌组织染色结果对照。结果　心肌造影时间 -强度曲线中 ,两组缺血低灌注区峰值强度 ,时间 -强度曲线下面积 ,比正常灌注区明显减低 ,峰值减半时间比正常灌注区延长 ,差异有显著性 ,缺血再灌注组、缺血低灌注区与正常灌注区心肌视频密度时间 -强度曲线参数比值较硝酸甘油组降低更明显 ,差异有显著性 ,MCE所测定的心肌坏死区面积与危险区面积之比与伊文思蓝及 TTC心肌组织染色结果成正相关。硝酸甘油可使心肌     

对心肌预缺血保护作用的实验研究心肌声学造影超声心动图三维重建

目的 探讨心肌声学造影超声心动图三维重建（3D－MCE）对心肌预缺血（IP）的估测。方法 套扎健康犬左前降支或左旋支,建立开胸犬IP模型。IP组犬4只及再灌注（IR）组犬5支分别于基础状态、缺血4h、缺血后再灌注1h,应用经胸三维超声探头,经左房注射自制的声振5％白蛋白对其进行3D－MCE检查,并三维重建。动物处死后将左室短轴分为5－6个断面,用TTC病理染色确定危险心肌与梗死面积。结果 ①3D－MCE显示心肌总质量及造影剂充盈缺损心肌质量与病理实测值高度相关（r分别为0．93,0．92）。②3D－MCE及TTC染色结果均显示IP组心肌受损范围小于IR组。③IP组再灌注1h后灌注缺损心肌质量与再灌注即刻差异无显著性意义,P＞0．05。IR组再灌注1h后灌注缺损心肌质量较再灌注即刻增加,P＜0．05。结论 3D－MCE在定量诊断心肌梗死和心肌缺血范围时,可重复动态观察IP对活体心肌的保护作用。     

白细胞靶向超声造影显像无创评价犬心肌缺血再灌注损伤

目的 用白细胞靶向超声造影剂无创评价犬心肌缺血再灌注（ischemia-reperfusion，I-R）损伤的范围及严重程度。 方法 将自制“表活显”（self-made surfactant fluorocarbon-filled microbubbles，SFCMB）与磷脂酰丝氨酸（phosphatidylserine，PS）结合，制备成白细胞靶向超声造影剂（SFCMB-PS），在实时心脏超声造影（myocardial contrast echocardiography，MCE）条件下，用SFCMB-PS对9只犬心肌I-R模型进行延迟心肌显像。实验结束后，在心肌I-R损伤处取组织块立即进行髓过氧化物酶（myeloperoxidase，MPO）活性测定。 结果 延迟心肌显像可见缺血心肌部位有明显充盈缺损，而再灌注后心肌的造影剂回声明显增强。定量分析结果表明I-R损伤心肌部位声像图的灰阶强度与MPO活性有明显的相关关系（r=0．776，P〈0．05）。 结论 用白细胞靶向超声造影剂评价心肌I-R损伤有明显的临床价值。     

超声造影定量小鼠肾血流灌注的研究

目的评估超声造影定量小鼠肾脏血流灌注的可靠性。方法雌性小鼠7只,经颈静脉匀速泵入微泡造影剂,全程记录造影图像,脱机定量造影剂再充填曲线参数,软件自动计算声学造影平台强度、再充填曲线上升斜率以及两者乘积。比较小鼠两次造影结果的一致性,并评估造影强度对造影定量曲线拟合优度的影响。结果所有小鼠均取得良好的肾脏显影效果。全部造影定量分析曲线的拟合优度极佳,其决定系数高达0．945±0．050（P〈0．05）。在一定范围内,超声造影平台强度与超声造影定量曲线的拟合优度之间呈正相关（r=0．760,P=0．002）。同一只小鼠两次超声造影的肾脏血管密度、血流速度及肾血流量比较差异均无统计学意义（P〉0．05）。结论应用超声造影定量小鼠肾脏血流有良好的重复性,提高超声造影平台强度,对于改善定量分析结果有一定的帮助。     

心肌声学造影无创评价犬急性冠状动脉闭塞缺血心肌及侧支循环的状态

目的：探讨经静脉心肌志学造影在动态评价犬急性冠状动脉闭塞时缺血、坏死心肌，及侧支循环逐步建立开放中的价值。方法：7只健康杂种犬，分别于基础状态，左冠前降支（LAD）结扎即刻、结扎后3h行经静脉心肌声学造影（MCE）。定量分析冠脉闭塞后心肌低灌注区视频密度峰值（VI），测量充盈缺损区面积，监测血流动力学变化。结果：1只犬于LAD结扎2min时因发生室颤死亡，统计分析时剔除，其余6只犬经静脉MCE未见血流动力学影响。LAD结扎3h的造影充盈缺损面积小于结扎即刻（P＜0．001）；LAD结扎3h的心肌低灌注区视频密度峰值较结扎即刻明显增加（P＜0．001）；心肌病理染色确定的坏死心肌部位在MCE的充盈缺损范围内。结论：MCE是反映心肌血流灌注的安全、有效方法，可准确评价冠脉急性闭塞时心肌血流灌注的变化及侧支循环状态。     

心肌声学造影评价急性心肌梗死患者心肌微循环的研究

目的 探讨心肌声学造影（MCE）评价急性心肌梗死（AMI）患者心肌微循环灌注的临床应用价值。方法 选择24例AMI患者,在冠状动脉造影前2d内,应用声诺维（SonoVue）经静脉注射,行间歇触发、二次谐波MCE检查,取左室短轴乳头肌水平切面,应用声学密度分析软件,定量各节段心肌声学密度的峰值强度（PI）、曲线下面积（AUC）;根据冠脉造影的结果,按冠脉直径狭窄程度（狭窄＜50％、50％≤狭窄＜70％、70％≤狭窄＜90％、狭窄≥90％）将其所供应的心肌节段的分为4组,分别进行组间声学密度参数的比较,并与冠脉的狭窄程度进行相关分析。结果 24例患者均顺利完成MCE检查。4组间的微循环灌注参数均存在显著差异（P＜0.05）,随冠脉狭窄程度的加重,其心肌微循环灌注参数（PI、AUC）指标降低越明显（P均＜0．01）,但其与冠脉狭窄程度均无明显相关性（P＞0．05）。结论 心肌声学造影可评价心肌微循环灌注,但其微循环灌注并非与冠脉狭窄程度完全一致。     

实时心肌超声造影评价急性心肌缺血的实验研究

目的 评价实时心肌超声造影(MCE)识别大鼠急性心肌梗死心梗范围的准确性,及定量分析缺血心肌血流灌注的特性.方法 雄性Wistar大鼠20只,结扎冠脉左前降支,制备急性心肌梗死(AMI)模型.分别采集基础状态及梗死状态下的RT-MCE 图像.分别在缺血区和灌注正常的心肌取感兴趣区,得出造影成像的强度-时间曲线,读出峰值视频强度PI、A、β、A·β值.结果 MCE显示梗死区灌注充盈缺损,灌注缺损区面积(30.67±6.42)%与病理染色证实的心梗面积相关性好(r=0.87).心梗区PI较正常灌注区低 (5.45±3.07) dB vs (23.03±5.27) dB (P<0.05).灌注缺损区的A、β、A·β值等均与正常心肌MCE灌注参数值间存在显著差异(P<0.05).结论 MCE能无创地准确估测梗死面积.梗死区MCE血流灌注指标显著降低.     

应用心肌声学造影评价动脉粥样硬化心肌微血管内皮功能的实验研究

目的应用心肌声学造影（myocardial contrast echocardiography，MCE）探讨兔动脉粥样硬化（atherosclerosis，AS）心肌微血管内皮功能的变化。方法20只兔高胆固醇喂养至12周，分别于喂养0、4、8、12周经静脉注射自制氟碳微泡造影剂行MCE，获得经主动脉根部注射乙酰胆碱（acetylcholine，ACC）和硝酸甘油（nitroglycerin，NG）后、前时间一强度曲线参数中峰值强度比值（peakintensity ratio，PIR）和曲线下面积比值（areaunder curve ratio，AUCR），表示微血管内皮依赖性舒张功能（endothelium dependent dilatation，EDD）和内皮非依赖性舒张功能（non—endothelium dependent dilatation，NEDD）。结果注射ACC后0周PI及AUC不同程度增高。4周增高程度明显下降（P〈0．01），而8周及12周均较注射前减低（P〈0．01）。注射NG后各时间段P1及AUC均增高。结论应用MCE技术，可以定量分析AS心肌微血管EDD和NEDD的改变，AS心肌微血管EDD随AS的进程而逐渐减低，而NEDD变化不大。     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.