剪切波弹性成像检测脑梗死患者颈动脉粥样斑块的易损性

目的应用剪切波弹性成像技术检测颈动脉粥样斑块的弹性模量,评估脑梗死患者斑块的易损性。方法选取我院急性脑梗死患者60例(脑梗死组)和91例非脑梗死患者(对照组),应用剪切波弹性成像测量两组颈动脉斑块的杨氏模量值[平均值(Emean)、最小值(Emin)、最大值(Emax)及标准差(Sd)],并对其进行比较分析。结果脑梗死组颈动脉斑块Emean、Emin分别为(18.17±15.29)k Pa、(10.36±8.73)k Pa,均低于对照组[(27.11±17.10)k Pa、(15.86±15.60)k Pa],差异均有统计学意义(均P<0.05)。结论剪切波弹性成像技术可通过检测颈动脉斑块的杨氏模量平均值和最小值评估斑块的易损性,或可作为预测脑梗死发生的风险参数。     

剪切波超声成像定量参数评价颈动脉斑块易损性

目的：探讨超声剪切波弹性成像（SWE）技术定量参数评估颈动脉粥样硬化斑块组成和易损性的能力。方法对126例颈动脉粥样斑块患者进行常规超声和剪切波弹性成像,常规将其分为均质斑块组和不均质斑块组,应用SWE 弹性模量参数来定量评价不同类型斑块的杨氏模量值及其分布特征,比较不同类型颈动脉斑块及斑块内部低无回声区的超声弹性特征。结果126例患者中,颈动脉常规超声共检出193个斑块,其中均质斑块136个,不均质斑块57个。剪切波超声弹性图像显示均质斑块为较均匀分布的蓝绿色,不均质斑块弹性图像颜色混杂呈红蓝相间。不均质斑块组整体斑块的平均、最小及最大杨氏模量值均明显低于均质斑块组（ P 均<0.05）,不均质斑块组整体斑块的杨氏模量 SD 值高于均质斑块组（ P <0.05）。均质斑块组和不均质斑块组的的斑块内低无回声区的平均、最小、最大弹性模量值均低于整体斑块（ P 均<0.05）。结论应用超声剪切波弹性成像技术能观察到斑块脂质核心的弹性特征,有助于识别颈动脉易损斑块。     

实时剪切波超声弹性成像技术评估帕金森病患者骨骼肌弹性模量的研究

目的研究帕金森病患者肱二头肌、肱桡肌、股直肌及小腿三头肌长轴杨氏模量值特征,探讨实时剪切波超声弹性成像技术评估帕金森病患者肌肉状态的应用价值。方法选取46例帕金森病患者(病变组)和健康志愿者31例(对照组),应用实时定量剪切波超声弹性成像技术获取病变组双侧、对照组右侧的肱二头肌、肱桡肌、股直肌及小腿三头肌松弛状态下长轴杨氏模量值,并进行对比分析。结果放松状态下病变组患者症状明显侧、症状较轻侧及对照组肱二头肌长轴杨氏模量值分别为(59.94±20.91)k Pa、(47.77±24.00)k Pa及(24.44±5.09)k Pa;肱桡肌长轴杨氏模量值分别为(32.18±17.19)k Pa、(28.41±13.19)k Pa及(21.71±7.45)k Pa;股直肌长轴杨氏模量值分别为(15.74±12.16)k Pa、(16.13±11.61)k Pa及(10.25±7.89)k Pa;小腿三头肌长轴杨氏模量值分别为(20.77±10.18)k Pa,(20.63±11.83)k Pa及(9.32±4.75)k Pa。病变组患者双侧肱二头肌、肱桡肌、股直肌及小腿三头肌长轴杨氏模量均高于对照组(均P0.05);症状明显侧肱二头肌长轴杨氏模量高于症状较轻侧(P0.05),病变组患者双侧肱桡肌、股直肌及小腿三头肌长轴杨氏模量比较差异无统计学意义。结论实时定量剪切波弹性成像技术可检测帕金森病患者较大骨骼肌杨氏模量值差异,为评估帕金森病患者肌肉状态提供了一种新的检测方法。     

实时超声弹性成像评价颈动脉粥样硬化斑块

目的 探讨实时超声弹性成像评价颈动脉粥样硬化斑块的价值.方法 33例患者中,常规超声发现斑块45处,并将其分为软斑块、纤维斑块、混合性斑块及钙化斑块;观察不同斑块的弹性图像特点并计算颈总动脉内血液组织与斑块的应变对比度(即硬度比值).结果 ①二维超声发现软斑块17处,纤维性斑块0处,混合性斑块15处.钙化斑块13处.②超声弹性图像中,软斑块主要表现为绿色,混合性斑块表现为蓝绿相间,而钙化斑块则完全为蓝色所覆盖.③钙化斑块组及混合性斑块组应变对比度明显高于软斑块组,差异有统计学意义(P<0.001,P<0.05);钙化斑块组应变对比度明显高于混合性斑块组,差异有统计学意义(P<0.001).结论 超声弹性成像技术可以用于评价颈动脉斑块.不同组织声学特性的斑块弹性图像表现及应变对比度不同.     

实时超声弹性成像评价颈动脉粥样硬化斑块

目的 探讨实时超声弹性成像评价颈动脉粥样硬化斑块的价值.方法 33例患者中,常规超声发现斑块45处,并将其分为软斑块、纤维斑块、混合性斑块及钙化斑块;观察不同斑块的弹性图像特点并计算颈总动脉内血液组织与斑块的应变对比度(即硬度比值).结果 ①二维超声发现软斑块17处,纤维性斑块0处,混合性斑块15处.钙化斑块13处.②超声弹性图像中,软斑块主要表现为绿色,混合性斑块表现为蓝绿相间,而钙化斑块则完全为蓝色所覆盖.③钙化斑块组及混合性斑块组应变对比度明显高于软斑块组,差异有统计学意义(P<0.001,P<0.05);钙化斑块组应变对比度明显高于混合性斑块组,差异有统计学意义(P<0.001).结论 超声弹性成像技术可以用于评价颈动脉斑块.不同组织声学特性的斑块弹性图像表现及应变对比度不同.     

超声造影和剪切波弹性成像评估颈动脉斑块及其与急性冠状动脉综合征的关系

目的应用超声造影联合剪切波弹性成像技术评估颈动脉斑块,探讨颈动脉斑块性质与非ST抬高型急性冠状动脉综合征(ACS)的关系。方法选取我院冠状动脉粥样硬化性心脏病(以下简称冠心病)患者88例,分为非ST抬高型ACS 45例(ACS组)和稳定性冠心病43例(SCHD组)。均行颈动脉常规超声检查是否存在颈动脉斑块,剪切波弹性成像及超声造影评估颈动脉斑块的弹性及造影强度,比较两组上述参数的差异。采用Logistic回归分析ACS发生的独立危险因素。结果常规超声显示ACS组中低回声斑块检出率和混合回声斑块检出率均高于SCHD组,差异均有统计学意义(均P0.05)。超声造影显示ACS组斑块最大增强强度和最大增强密度均较SCHD组增高,达峰时间较SCHD组缩短,差异均有统计学意义(均P0.05)。剪切波弹性成像显示ACS组斑块平均杨氏模量值明显低于SCHD组,差异有统计学意义(P0.05)。Logistic回归分析显示,颈动脉斑块最大增强密度是ACS发生的独立危险因素(OR=2.853,95%可信区间0.161～7.091,P=0.027)。结论超声造影和剪切波弹性成像技术均能定量分析颈动脉斑块的稳定性与易损性,为预测冠状动脉病变的发生提供参考依据。     

实时剪切波弹性成像在非酒精性脂肪肝分度诊断中的应用价值

目的探讨实时剪切波弹性成像(SWE)在非酒精性脂肪肝分度诊断中的应用价值。方法将158例非酒精性脂肪肝患者(脂肪肝组)分为轻度(n=52)、中度(n=51)、重度(n=55)3个亚组,另选健康成人50例为正常对照组。所有受检者均行常规超声扫查,再应用SWE测量肝杨氏模量值,比较各组杨氏模量值的差异。Spearman相关分析肝杨氏模量值与肝脏脂肪变程度的关系。结果正常对照组与脂肪肝组肝脏杨氏模量值分别为(4.79±0.77)k Pa和(4.51±0.57)k Pa,两组比较差异有统计学意义(t=2.562,P0.05)。轻、中、重度脂肪肝组杨氏模量值分别为(4.73±0.68)k Pa、(4.49±0.58)k Pa及(4.42±0.61)k Pa,正常对照组及脂肪肝各亚组间肝杨氏模量值比较差异有统计学意义(F=3.965,P0.05),轻、重度脂肪肝组间比较差异有统计学意义(t=0.338,P0.05),轻度脂肪肝组与正常对照组及中度脂肪肝组比较差异均无统计学意义。肝杨氏模量值与肝脏脂肪变程度呈弱负相关(r=-0.185,P0.05)。结论 SWE在评价脂肪肝分度上具有一定临床价值,可推广应用。     

剪切波弹性成像在慢性肾脏疾病诊断中的初步研究

目的探讨剪切波弹性成像技术在慢性肾脏疾病早期诊断中的应用价值。方法应用剪切波弹性成像技术测量并比较30例经左肾穿刺活检确诊为慢性肾脏疾病患者(病例组)和30例正常健康成人(正常对照组)的左肾皮质部、髓质部及肾窦部杨氏模量最大值(Emax)和平均值(Emean)。绘制受试者工作特征(ROC)曲线并计算曲线下面积以评价各部位杨氏模量值诊断慢性肾脏疾病的效能。结果正常对照组左肾皮质部Emax和Emean分别为(3.47±0.54)k Pa、(1.87±0.68)k Pa,髓质部Emax和Emean分别(2.45±1.09)k Pa、(1.08±0.68)k Pa,肾窦部Emax和Emean分别(9.01±3.74)k Pa、(7.49±2.77)k Pa,3个部位Emax和Emean值比较差异均有统计学意义(均P0.01)。病例组左肾皮质部Emax和Emean分别为(4.12±1.71)k Pa、(2.76±1.06)k Pa,髓质部Emax和Emean分别为(2.57±1.07)k Pa、(1.27±0.68)k Pa,肾窦部Emax和Emean分别为(8.76±2.45)k Pa、(6.78±2.57)k Pa,3个部位Emax、Emean比较差异均有统计学意义(均P0.05)。两组肾皮质部Emax、Emean比较差异均有统计学意义(均P0.05)。皮质部杨氏模量值诊断慢性肾脏疾病的ROC曲线下面积为0.758,当截断值为3.15 k Pa时,其诊断准确率和特异性分别为56.7%、63.3%。结论慢性肾脏疾病肾脏皮质部硬度变化与病变部位及程度密切相关,剪切波弹性成像可定量评价肾脏不同部位的杨氏模量值,为临床肾脏疾病诊断提供更丰富诊断信息。     

实时剪切波弹性成像检测正常成人冈上肌肌腱杨氏模量值的初步研究

目的探讨应用实时剪切波弹性成像技术测量正常成人冈上肌肌腱杨氏模量值范围,分析不同性别、不同体位、是否优势手对测值的影响。方法选取80例健康受试者,对同一受试者优势手及非优势手分别于肩关节Crass位及改良Crass位进行杨氏模量测值;对不同性别、不同体位及是否优势手之间杨氏模量值进行统计分析。结果正常成人优势手Crass位和改良Crass位、非优势手Crass位和改良Crass位杨氏模量值分别为(450.76±205.39)k Pa、(439.15±177.68)k Pa、(443.07±195.21)k Pa及464.65±268.23)k Pa,两两比较差异均无统计学意义;男、女性别间除了非优势手Crass位杨氏模量值差异无统计学意义外,优势手的不同体位及非优势手改良Crass位杨氏模量值比较差异均有统计学意义(均P0.05)。结论实时剪切波弹性成像可获得正常成人冈上肌肌腱的杨氏模量值,为后续的其他肌腱研究提供参考,并为冈上肌肌腱病变硬度值研究提供正常对照。     

剪切波弹性成像评价不同回声颈动脉斑块的弹性特征

目的探讨剪切波弹性成像(SWE)评估不同回声颈动脉斑块弹性特征的价值。方法对145例颈动脉斑块患者行颈动脉超声及SWE检查,采用两种斑块回声分类方法对斑块进行分类,比较不同回声特征颈动脉斑块的杨氏模量值。结果低回声、等回声、强回声及不均质回声最大杨氏模量值、平均杨氏模量值比较差异均有统计学意义(均P0.05),两两比较差异均有统计学意义(均P0.05);最小杨氏模量值在四种回声斑块中的差异均有统计学意义(均P0.05),两两比较除低回声与等回声之间差异无统计学意义外,其余差异均有统计学意义(均P0.05)。Ⅰ~Ⅳ型斑块最大杨氏模量值、平均杨氏模量值比较差异均有统计学意义(均P0.05),两两比较除Ⅲ型和Ⅳ型斑块之间差异无统计学意义外,其余差异均有统计学意义(均P0.05);四种回声斑块中最小杨氏模量值比较差异均有统计学意义(均P0.05),两两比较除Ⅰ型和Ⅱ型斑块之间差异无统计学意义外,其余差异均有统计学意义(均P0.05)。结论 SWE技术可以定量评估颈动脉斑块的弹性特征,能够反映不同回声斑块间的弹性差异。     

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.     

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.