三维斑点追踪技术评价类风湿关节炎患者左心室收缩功能

目的 应用三维斑点追踪技术（3D-STI）评价类风湿关节炎（RA）患者左心室收缩功能。方法 对40例RA患者（RA组）、40名健康体检者（对照组）行常规超声心动图检查,测量参数左心室舒张末期内径（LVDd）、左心室收缩末期内径 （LVDs）、室间隔舒张末期厚度（IVSd）、左心室后壁舒张末期厚度（LVPWd）、二尖瓣口舒张期E峰、A峰、E/A值、左心室舒张末期容积（EDV）、左心室收缩末期容积（ESV）、左心室射血分数（LVEF）;同时采集3D-STI图像,并应用4D Auto LVQ软件分析计算出左心室收缩期整体纵向应变（LVGLS）、左心室收缩期整体径向应变（LVGRS）、左心室收缩期整体圆周应变（LVGCS）、左心室收缩期整体面积应变（LVGAS）,比较RA组与对照组常规超声心动图及3D-STI参数的差异。结果 RA组与对照组LVDd、LVDs、 IVSd、LVPWd、E峰、A峰、E/A值、EDV、ESV、LVEF的差异均无统计学意义（P均>0.05）。两组间LVGLS、LVGRS、LVGCS、LVGAS差异均有统计学意义（P均<0.05）。结论 3D-STI技术可较常规超声心动图更早地检测出RA患者左心室收缩功能的改变。     

三维斑点追踪技术定量评价动脉导管未闭合并肺动脉高压患者左心室整体应变

目的 探讨三维斑点追踪技术（3D-STI）定量评价动脉导管未闭（PDA）患者左心室整体收缩功能的价值。方法 随机选取常规超声心动图确诊为PDA的患者51例（病例组）,其中单纯PDA35例（单纯PDA亚组）,合并肺动脉高压（PAH）16例（合并PAH亚组）;另选取性别、年龄相匹配的健康体检者35名（对照组）。所有研究对象分别接受常规超声心动图检查及3D-STI检查,获取左心室舒张末期内径（LVDD）、左心室收缩末期内径（LVDS）、左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）、左心室射血分数（LVEF）、左心室整体纵向应变（GPLS）、整体圆周应变（GPCS）、整体径向应变（GPRS）以及整体面积应变（GPAS）等指标,并行统计分析。结果 单纯PDA亚组的PAD、LVDD、LVDS、LVEDV、LVESV、GPLS、GPCS、GPRS和GPAS均高于对照组（P均 < 0.05）。合并PAH亚组的PAD、LVDD、LVDS、LVEDV均高于对照组,GPAS低于对照组（P均 < 0.05）。3组LVEF差异无统计学意义（P > 0.05）。单纯PDA亚组的PAP、PD、PAD明显低于合并PAH亚组,而GPLS、GPCS、GPRS和GPAS高于合并PAH亚组（P均<0.05）。结论 3D-STI检查可有效评价PDA患者LVEF正常时左心室整体应变变化,且单纯PDA患者左心室整体应变明显增强,合并有PAH时整体应变下降。     

纵向分层应变技术评估蒽环类药物化疗后乳腺癌患者左心收缩功能

目的 应用二维分层应变技术评估蒽环类药物化疗后乳腺癌患者早期左心室收缩功能的变化。方法 收集接受蒽环类药物化疗的乳腺癌患者32例及未接受化疗的乳腺癌术后患者20例。化疗患者于化疗3个月、5个月后接受常规超声心动图采集图像,应用EchoPAC软件测量左心室长轴各切面收缩期心内膜下、中层和心外膜下心肌的整体纵向应变（GLS）及各节段（基底段、中间段、心尖段）的纵向应变。结果 与对照组比较,随着化疗周期的增加,蒽环类药物化疗后乳腺癌患者心内膜下、中层和心外膜下心肌GLS均减低（P均<0.05）,而左心室射血分数（LVEF）无显著差异（P>0.05）;与对照组比较,除各层心肌心尖段外,化疗后患者各层心肌基底段、中间段纵向应变减低（P均<0.05）。结论 纵向分层应变技术可准确评估乳腺癌蒽环类药物化疗后左心各层心肌整体及局部收缩功能,为判断心肌损伤程度提供了新的方法。     

速度向量成像分层应变技术评价血液透析对尿毒症患者左心室心肌即时纵向应变的影响

目的 观察速度向量成像（VVI）分层应变技术评价尿毒症血液透析患者左心室心肌即时纵向应变功能变化的价值。方法 对35例接受高通量血液透析的尿毒症患者分别于透析前和透析后2 h行二维超声心动图检查。常规测量并采集图像后,应用VVI软件分析二维动态图像,获得左心室17个节段3层心肌收缩期纵向峰值应变（LPS）。结果 透析后左心房收缩期前后径、左心室舒张末期和收缩末期内径、左心室舒张末期和收缩末期容积、每搏输出量均较透析前减小（P均<0.05）,左心室射血分数差异无统计学意义（P=0.183）。与透析前比较,透析后2 h左心室整体全层、内层,基底段全层、内层、中层、外层,中间段全层、内层心肌收缩期LPS均较透析前减低（P均<0.05）;左心室整体外层、中层,中间段外层、中层,心尖段全层、内层、中层、外层心肌LPS差异均无统计学意义（P均>0.05）。结论 VVI分层应变技术可敏感、准确地评价血液透析对尿毒症患者即时左心室心肌整体及局部收缩功能的影响。     

三维斑点追踪成像技术定量评价亚临床甲状腺功能亢进患者左心室收缩功能

目的 探讨三维斑点追踪成像（3D-STI）技术定量评价亚临床甲状腺功能亢进（SH）患者左心室收缩功能的价值。方法 对33例未经治疗SH患者（SH组）及性别、年龄相匹配的35名健康志愿者（对照组）进行实验室检查、常规超声及3D-STI检查,获取实验室指标促甲状腺激素（TSH）、三碘甲状腺原氨酸（T₃）、甲状腺素（T₄）、游离甲状腺素（FT₄）,左心室常规指标左心房内径（LAD）、室间隔厚度（IVST）、左心室舒张末期内径（LVEDD）、左心室收缩末期内径（LVEDS）、左心室射血分数（LVEF）及左心室整体和17节段纵向、径向和面积峰值应变,比较2组差异。结果 SH组与对照组间TSH、T₄和FT₄差异均有统计学意义（P均<0.05）,LAD、IVST、LVEDD、LVEDS、LVEF差异均无统计学意义（P均>0.05）。SH组与对照组间左心室中间段下侧壁、心尖段下壁的面积峰值应变,心尖段下壁及心尖帽的径向峰值应变差异均无统计学意义（P均>0.05）,SH组心脏整体及其余各节段各峰值应变均较对照组降低（P均<0.05）。SH患者左心室整体面积峰值应变与TSH呈正相关（r=0.82,P<0.01）,与FT₄呈负相关（r=-0.67,P<0.01）。结论 3D-STI技术可早期定量评价SH患者左心室整体及局部收缩功能;SH患者左心室各节段应变值呈弥漫性下降。     

二维应变参数评价扩张型心肌病患者左心室收缩同步性及其与心功能的关系

目的 探讨二维斑点追踪成像（2D-STI）应变参数评价扩张型心肌病（DCM）患者左心室收缩同步性的价值及其与心功能的关系。方法 收集DCM患者（DCM组）及对照组各25例,采用2D-STI技术获取左心室各节段纵向应变达峰时间、圆周应变达峰时间（Tls、Tcs）,分别计算左心室18节段纵向应变达峰时间标准差（Tls-SD）及最大差值（Tls-dif）,左心室心尖四腔心、三腔心、二腔心切面6节段纵向应变达峰时间标准差（Tls-SD-4、Tls-SD-3、Tls-SD-2）及最大差值（Tls-dif-4、Tls-dif-3、Tls-dif-2）,左心室18节段圆周应变达峰时间标准差（Tcs-SD）及最大差值（Tcs-dif）,左心室短轴二尖瓣、乳头肌、心尖水平6节段圆周应变达峰时间标准差（Tcs-SD-M、Tcs-SD-P、Tcs-SD-A）及最大差值（Tcs-dif-M、Tcs-dif-P、Tcs-dif-A）。结果 与对照组比较,DCM组整体及节段应变参数均显著增大（P均<0.05）;DCM组中,除Tcs-dif-P、Tcs-dif外,余应变参数均与左心室射血分数呈负相关（P均<0.05）;除Tcs-dif-M、Tcs-dif-P及Tcs-dif外,余应变参数均与舒张早期二尖瓣口峰值血流速度（E）/二尖瓣环运动速度（e）呈正相关（P均<0.05）。结论 DCM患者左心室整体及局部收缩期应变均存在不同步,收缩不同步可加剧心功能的恶化;2D-STI参数可以客观评价DCM患者左心室收缩不同步及其与心功能的关系。     

三维斑点追踪技术评价阻塞型睡眠呼吸暂停低通气综合征伴高血压患者左心室整体收缩功能

目的 应用三维斑点追踪（3D-STI）技术评价阻塞型睡眠呼吸暂停低通气综合征（OSAHS）伴高血压（HT）患者左心室整体收缩功能。方法 OSAHS 40例,分为单纯OSAHS组20例和OSAHS+HT组20例;另选择20名健康正常人作为正常对照组。行常规超声心动图检查,采集左心室心尖四腔三维全容积图像,存储图像并应用3D-STI分析软件在线分析,计算左心室整体纵向收缩峰值应变（GLS）、左心室整体径向收缩峰值应变（GRS）、左心室整体圆周收缩峰值应变（GCS）及左心室整体面积收缩峰值应变（GAS）。结果 与正常对照组相比,OSAHS组 左心室GLS、GRS、GAS减低（P均<0.05）,OSAHS+HT组左心室GLS、GRS、GCS、GAS均减低（P均<0.05）。与OSAHS组比较,OSAHS+HT组 左心室GLS、GCS、GAS均减低（P均<0.05）。结论 OSAHS合并HT患者存在左心室收缩功能受损。3D-STI能早期、准确有效地评估其左心室整体收缩功能改变。OSAHS患者心脏结构及功能变化独立于HT而单独存在,二者同时存在时改变加重。     

斑点追踪技术评估冠状动脉心脏病患者冠状动脉狭窄程度

目的 观察斑点追踪成像（STI）技术评价冠状动脉心脏病患者冠状动脉狭窄严重程度的价值。方法 对74例拟诊冠状动脉心脏病患者[冠状动脉狭窄组（n=59）和冠状动脉无狭窄组（n=15）]行常规超声和STI技术检查。根据冠状动脉Gensini评分将冠状动脉狭窄组分为轻、中、重度狭窄3个亚组。测量左心室整体平均纵向应变（GLS-Avg）、基底段平均纵向应变（GLS-Bas）、中间段平均纵向应变（GLS-Mid）及心尖段平均纵向应变（GLS-AP）,比较两组间及3个亚组间的差异。结果 冠状动脉狭窄组GLS-Avg、GLS-Bas、GLS-Mid及GLS-AP均低于冠状动脉无狭窄组（P均<0.001）。冠状动脉狭窄组中,随着冠状动脉狭窄程度增加,GLS-Avg、GLS-Bas、GLS-Mid、GLS-AP降低,轻、中、重度狭窄亚组间两两比较差异均有统计学意义（P均<0.05）。冠状动脉狭窄组GLS-Avg、GLS-Bas、GLS-Mid及GLS-AP与Gensini评分均呈正相关（r=0.861、0.847、0.819、0.778,P均<0.05）。结论 采用STI技术获得的左心室整体纵向应变值可在一定程度上反映冠状动脉心脏病患者冠状动脉狭窄程度。     

阻塞性睡眠呼吸暂停综合征患者早期左心室功能改变

目的 探讨阻塞性睡眠呼吸暂停综合征（OSAS）患者左心室形态改变前收缩和舒张功能改变。方法 将111例OSAS患者分为OSAS伴左心室肥厚（LVH）组（29例）及OSAS无LVH组（82例）,同时设正常对照组50名,行常规超声心动图及二维斑点追踪成像（2D-STI）检查,比较3组间常规超声心动图及2D-STI指标的差异,分析超声指标与临床指标的相关性。结果 OSAS伴LVH组与其他2组相比左心室质量指数（LVMI）、室间隔舒张末期厚度（IVST）、左心室后壁舒张末期厚度（PWT）、左心室舒张末期内径（LVIDd）、二尖瓣舒张早期峰值流速与二尖瓣环舒张早期运动速度比值（E/e''）及左心房容积指数（LAVI）增大（P均<0.05）,室间隔及左心室侧壁二尖瓣环舒张早期运动速度（e''）减小（P均<0.05）;其二尖瓣环收缩期运动速度（s''）小于正常对照组（P=0.013）。OSAS伴LVH组与其他2组相比左心室整体纵向收缩期应变（S）及舒张早期应变率（SR_E）减小（P均<0.05）,二尖瓣舒张早期峰值血流速度与舒张早期应变率比值（E/SR_E）增大（P均<0.05）,其左心室整体纵向收缩期应变率（SR_S）小于正常对照组（P=0.001）。与正常对照组比较,OSAS无LVH组S、SR_S及SR_E减小（P均<0.05）,E/SR_E增大（P<0.001）。S、E/SR_E均与睡眠呼吸暂停低通气指数独立相关（P均<0.05）,LVMI与平均血氧饱和度独立相关（标准化系数=-0.299,t=-3.273,P=0.001）。结论 OSAS可影响左心室结构及功能,在左心室形态发生明显改变前,LV收缩及舒张功能已受损。     

三维斑点追踪成像技术评价房间隔缺损患者封堵前后左心室整体应变

目的 探讨三维斑点追踪成像（3D-STI）技术定量评价房间隔缺损（ASD）患者封堵前后左心室整体应变。方法 选取介入封堵成功的继发孔型ASD患者35例,分别于术前、术后2天和1、3、6个月接受常规超声心动图检查及3D-STI检查。常规超声心动图检查获取左心室舒张末期内径（LVEDD）、左心室收缩末期内径（LVEDS）、左心室舒张末期容积（LVEDV）,左心室收缩末期容积（LVESV）、每搏量（SV）。采用3D-STI检查获取左心室整体纵向峰值应变（GPLS）、左心室整体圆周峰值应变（GPCS）、左心室整体径向峰值应变（GPRS）和左心室整体面积峰值应变（GPAS）。对术前与术后各时间点参数行统计学分析。结果 常规超声心动图检查示ASD患者术后各时间点LVEDD、LVEDS、LVEDV、LVESV、SV较术前增加（P均<0.05）,但术后2天、1、3、6个月间两两比较,差异无统计学意义（P>0.05）。3D-STI检查结果示ASD患者术后各时间点左心室GPLS、GPCS、GPRS、GPAS较术前增加（P均< 0.05）,且以术后2天增加最为明显,术后6个月GPLS、GPCS、GPAS较术后3个月增加（P均< 0.05）。结论 3D-STI技术可全面、准确地评价ASD患者封堵前后左心室心肌应变,较常规超声心动图可更客观、有效地评价术后左心室收缩功能变化。     

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.     

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.     

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.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.