应变率成像技术评估圆锥动脉干畸形术后右心室功能

目的:应用应变率成像技术评估圆锥动脉干畸形(CTD)患者术后右心室功能变化。方法:27例CTD术后及27例正常儿童为研究对象,常规行超声心动图检查,分别采集右室游离壁应变率图像,测量各节段的收缩期峰值应变率(SRS)、应变(S)、舒张早期峰值应变率(SRE)、舒张晚期峰值应变率(SRA),研究CTD术后右心收缩功能的变化及变化规律。结果:CTD术后患儿与正常儿童相比,各心肌节段SRS、S、SRE、SRA值均显著下降,差异有统计学意义(P0.01)。病例组与正常组节段分布规律不同,各指标值在基底段、中间段和心尖段各节段之间无统计学差异(P0.05)。结论:CTD术后患儿依然存在右心室局部心功能的下降,应变率成像能简单、快速、准确、客观地反映右心室功能变化。     

应变和应变率成像评价左冠状动脉起源于肺动脉患者左心室局部心肌功能的研究

目的:探讨应变率成像技术评价左冠状动脉起源异常患儿局部心肌功能的临床应用价值.方法:应用应变率成像技术比较16例左冠状动脉起源于肺动脉(Anomlalous origin of the left coronary artery from the pulmonary artery,LCAPA)患儿与39例正常儿童左心室不同心肌节段的应变率值以及应变值.结果:对照组平均收缩期峰值应变率(-2.12±0.75)s-1,收缩期应变(-25.24±4.07)%,舒张早期应变率(2.32±0.69)s-1,舒张晚期应变率(1.65±0.61)s-1;病例组平均收缩期峰值应变率(-1.42±0.49)s-1,收缩期应变(-17.56±5.71)%,舒张早期应变率(1.48±0.49)s-1,舒张晚期应变率(0.85±0.42)s-1.病例组收缩期及舒张期应变率及应变均小于对照组,差异有显著意义(P<0.01).病例组室间隔基底段的应变率值及应变值与其它节段相比较差异有显著意义.病例组基底段收缩期峰值应变率(-2.22±.41)s-1,收缩期应变(-25.24±4.07)%,舒张早期应变率(2.32±0.69)s-1,舒张晚期应变率(1.65±0.61)s-1.结论:应变率成像技术可以评价左冠状动脉起源于肺动脉患者局部心肌功能.     

超声心动图评价低温条件下兔左室局部心功能的变化

目的探讨低温对兔心脏收缩及舒张功能的影响。方法将24只新西兰大白兔随机分为常温组和低温组,每组12只。分别置于室温(22~25℃)以及低温(-15~-18℃)条件下。应用常规超声比较两组射血分数(EF)、心率(HR)、舒张末期容积(EDV)、收缩末期容积(ESV)、每搏输出量(SV)、短轴缩短率(FS)。应用组织多普勒超声技术(TDI)检测兔心尖四腔心切面二尖瓣环的收缩期和舒张早期峰值运动速度和应变率。结果常规超声心动图显示,低温组HR明显低于常温组(P<0.01),但两组EDV、ESV、SV、EF及FS比较差异无统计学意义(P>0.05)。低温组室间隔侧二尖瓣环舒张早期运动速度(Em)及二尖瓣环两侧舒张早期的峰值应变率(SRe)均明显低于正常组(P<0.05)。低温组二尖瓣环收缩期运动速度(Sm)及收缩期峰值应变率(SRs)也低于正常组,但差异无统计学意义(P>0.05)。结论低温条件可引起兔心功能的减低,并以舒张功能减低为主。超声心动图可以早期发现低温对兔局部心功能的影响。     

波强度对川崎病患儿心功能变化的评价

目的:应用波强度(wave intensity,WI)评价川崎病(kawasaki disease,KD)患儿左室整体收缩和舒张功能变化。方法:本院确诊KD急性期患儿68例,随访至患儿进入恢复期作为病例组,另选无心血管并发症儿童40例作为对照组,对受检者左侧颈总动脉行WI检测,获得WI参数:校正后第一峰值(1ndW1),校正前第一峰值(Wd1),校正后第二峰值(2ndW2),校正前第二峰值(Wd2);颈总动脉僵硬度参数。Simpson法测量受检者左室整体射血分数(EF)和二尖瓣口血流频谱,获得E/A值,两期受检者及两组受检者参数进行对比。结果:与对照组及恢复期患儿比较,急性期患儿左侧颈总动脉僵硬度参数、EF值、E/A值无统计学差异(P>0.05);,急性期1stW1及Wd1与对照组及恢复期患儿比较无统计学差异(P>0.05),而2ndW2及Wd2较对照组及恢复期患儿明显减低,差异有统计学意义(P<0.05),恢复期患儿与对照组各参数比较未见明显差异(P>0.05)。结论:急性期川崎病患儿左室舒张功能会受损,WI技术可以经由颈总动脉无创早期评价KD患儿左心功能变化,并且比颈动脉僵硬度及常规心功能测量等参数更敏感。     

应变率显像对糖尿病患者左室舒张功能的评价

目的:探讨应变率显像(SRI)技术评价糖尿病患者左室舒张功能的临床价值。方法:获取33例糖尿病患者和26例正常人心尖左心长轴、二腔和四腔切面应变率曲线及组织多普勒曲线,分别测量左室各节段心肌舒张期峰值应变率和二尖瓣环舒张期峰值速度,计算左室平均峰值应变率(mSRe,mSRa)及比值(mSRe/mSRa)和二尖瓣环平均峰值速度((mVe,mVa)及比值(mVe/mVa)。常规测量二尖瓣口E、A、E/A值。结果:与正常组相比,糖尿病组舒张期mVe、mSRe、mSRe/mSRa、mVe/mVa均有明显降低(P<0.01),mSRe/mSRa与mVe/mVa呈高度正相关(r=0.793,P<0.01)。舒张早期DM组除后间隔基底段和侧壁基底段外其余节段SRe比正常对照组明显降低。结论:SRI检测出糖尿病患者早期存在左心室舒张功能异常,有助于舒张功能受损程度的判断,为以后定量评价糖尿病患者左室整体和局部舒张功能提供了无创性的新方法。     

室间隔缺损封堵术后左心功能的超声评价

目的应用超声心动图评价Amplatzer封堵器治疗室间隔缺损(VSD)患者于封堵术前后左心功能的变化。方法观察28例VSD患者封堵术前、术后1个月和术后6个月左室舒张末期内径(EDD)、舒张末期容积(EDV)、收缩末期容积()ESV、每搏输出量()SV、射血分数()和短轴缩短率()大小及变化。结果封堵术后1个月较术前差异具有显著性意义,EDDEFFS(P<0.05),EDV(P<0.001)ESV(P<0.05)SV(P<0.001)EF,FS无明显变化;封堵术后6个月,6项指标均恢复正常,较,,,术前差异具有显著性意义(P<0.001)。结论超声引导下VSD封堵术能够有效的改善VSD患者的左心功能。     

彩色多普勒超声心动图诊断主动脉缩窄

目的:探讨多普勒超声心动图对主动脉缩窄的诊断价值。方法:回顾性分析10例主动脉缩窄患者多普勒超声心动图检查结果与手术所见。结果:10例患者术前超声心动图检查诊断正确8例,漏诊2例(其中升主动脉管性缩窄1例,主动脉嵴部缩窄1例)。结论:彩色多普勒超声心动图能准确显示主动脉缩窄部位;动脉导管未闭(PDA)患者应常规探查主动脉弓及降主动脉。     

应用速度向量成像技术对川崎病儿童左心收缩功能的评价

目的探讨应用速度向量成像技术对川崎病儿童左心长轴方向收缩功能的价值。方法对24例急性期川崎病患儿(冠脉扩张8例)、27例恢复期川崎病患儿(冠脉扩张9例)与20例正常儿童进行超声心动图检查。于胸骨旁左室长轴切面测量各腔室径线;通过M型超声获得左室射血分数(EF);采集心尖四腔三个完整心动周期的动态图像,存入光盘中。应用VVI技术脱机分析室壁基底部、中间部、心尖段的收缩期峰值速度(Vmax)、应变(Smax)、应变率(SR-max)。结果急性期组收缩期峰值速度(Vmax)、收缩期峰值应变率(SRmax)低于正常组,在所有基底部和部分中间及心尖节段有统计学差异(P<0.05);恢复期组与正常组比较部分节段差异有统计学意义;恢复期组儿童同一室壁收缩期峰值应变率(SRmax)失去一致性。结论急性期和恢复期川崎病儿童均有不同程度的左室长轴方向收缩功能受损。     

应变率成像对急性前壁心肌梗死患者左心功能的评价

目的:观察急性前壁心肌梗死患者心肌应变率(SR)的变化特点,探讨应变率成像(SRI)技术定量评价急性心肌梗死(AMI)患者的左室局部心肌功的临床应用价值。方法:应用SRI对20例AMI患者和30例正常人左室各室壁节段纵向收缩期、舒张早期及房缩期的峰值应变率进行测定,并以冠脉造影结果为标准进行对比分析。结果:SRS:AMI组基底部、中部水平所有室壁较正常对照组显著性减低,心尖水平除下壁外其他室壁较对照组显著性减低;SRE:AMI组不同水平左室所有室壁较对照组显著性减低;SRA:基底部前间隔、后壁、前壁、下壁较对照组显著性减低,中部后间隔、后壁、前壁较对照组显著性减低,心尖水平后间隔、前壁、下壁AMI组较对照组显著性减低(P<0.01和0.05)。结论:SRI技术是临床无创、定量评价急性心肌梗死局部心肌功能的有效方法。     

双源CT血管成像在主动脉缩窄中的应用

目的:探讨双源CT血管成像(DSCTA)在主动脉缩窄诊断中的应用。材料和方法:对临床怀疑主动脉缩窄患者15例进行双源CT主动脉增强扫描,将获得的数据进行容积再现(VR)、多平面重建(MPR)、最大密度投影(MIP)、曲面重建(CPR),分析主动脉走行及心内外结构特征。结果:15例患者均诊断为主动脉缩窄,DSCTA图像显示了主动脉缩窄的部位、程度及侧支血管情况。15例中单纯性主动脉缩窄6例,复杂性主动脉缩窄9例,其中伴动脉导管未闭8例,室间隔缺损5例,房间隔缺损4例,肺动脉高压3例,主动脉弓发育不良2例,主动脉瓣合并二尖瓣畸形、主动脉左弓右降、左室流出道与主动脉瓣间局限性膨大各1例。结果与手术及数字减影血管造影(DSA)检查结果相一致。结论:双源CT血管成像方便、快捷、无创,是诊断主动脉缩窄重要方法。     

组织多普勒应变与二维应变检测左心室壁应变可靠性对比分析

目的:评价以组织多普勒技术为基础的应变(DT-ST)及以斑点追踪技术为基础的二维应变(2D-ST)测量左室壁应变的可靠性。方法:随机抽取40例作左室壁DT-ST及2D-ST分析,并选取同期40例正常人作为对照组。左室壁应变测量由2名观察者独立完成,每名观察者对每例患者用组织多普勒应变及二维应变析各测量2次。同一名观察者测量2次间及2名观察者间测量差异用重复检测方差分析比较,一致性用组里相关系数(ICC)描述,2名观察者间测量可靠性用Cronbach’s alpha系数描述。结果:①除观察者甲冠心病组的室间隔心尖段DT-ST 2次测量结果、观察者间对照组的左室侧壁中间段、心尖段DT-ST及观察者间冠心病组左室侧壁基底段及心尖段DT-ST测量结果差异有统计学意义外(P值均<0.05),余观察者内及观察者间各节段重复测量结果之间均无显著差异;②观察者内可靠性:对照组2D-STICC与DT-STICC相近,或略大于DT-STICC;而冠心病组除观察者乙室间隔中间段ICC外,余各节段2D-ST ICC均大于DT-STICC;③观察者间可靠性:冠心病组及对照组左室壁各节段2D-ST的Cronbach’s alpha系数均大于DT-ST Cron-bach’s alpha系数。结论:组织多普勒应变及二维应变检测室壁应变均具有较高可靠性,但二维应变法具有更高的观察者间可靠性。     

正常人左室心肌应变和应变率定量分析

目的:探讨正常人左室心肌组织应变和应变率的参考值范围和变化规律。方法:应用组织多普勒成像技术对正常人左室各段心肌组织进行应变和应变率定量分析。结果:左室心肌收缩期应变率峰值和应变值在心尖段,中间段和基底段之间无显著性差异。收缩期应变率峰值在室间隔和前壁大于侧壁和后壁,但差异无显著性。应变值在侧壁、后壁和前壁的相应节段心肌之间无显著的差异,但室间隔心肌应变值高于其他各个室壁。结论:应变值在室间隔最高,在其他各个室壁之间应变率和应变值无显著性差异。应变和应变率显像能够定量评价局部心肌的形变能力,为临床评价局部心肌功能提供了有效的方法。     

Additional value of qualitative strain ultrasound elastography and strain ratio in predicting thyroid malignancy

Objective

To detect if strain ultrasound elastography and strain ratio have additional value to the conventional grey scale ultrasound in predicting thyroid malignancy.

MR imaging of myotendinous strain.

Myotendinous strain predominantly exhibits pathognomonic MR features. Whenever a patient's musculoskeletal symptoms lack temporal correlation with exercise, MR imaging may be valuable in distinguishing strain injury from other disorders of the myotendinous unit. Compared with myotendinous strain, myositis ossificans has variable and nonspecific MR appearances that may simulate neoplasm and require biopsy for diagnosis.     

应变率成像评价单纯性肥胖儿童左室局部心肌的收缩功能

目的:探讨应变及应变率成像在评价单纯性肥胖儿童心肌收缩功能方面的临床价值.方法:肥胖组儿童30人,年龄10±4岁,按年龄及性别匹配的健康儿童30人为对照组,分别进行二维及组织多普勒超声检查,应用应变率技术对局部心肌进行定量分析.结果:肥胖儿童左房内径增大(P<0.05),左室下壁、侧壁及室间隔心肌收缩期峰值应变、应变率明显低于正常儿童(P<0.05).结论:应变率成像技术可敏感的检测出单纯性肥胖儿童左心室心肌收缩功能及特性的改变.     

Elastography ultrasound for breast lesions: fat-to-lesion strain ratio vs gland-to-lesion strain ratio

Objective

To compare the diagnostic performance of the fat-to-lesion strain ratio (FLR) and gland-to-lesion strain ratio (GLR) in the diagnosis of breast lesions.

Methods

This was an institutional ethics committee approved prospective study. One hundred and ninety-three breast lesions in 193 women (mean age, 46.03?±?13.60 years, range 18–82 years) were examined with conventional and elastographic US. Both the FLR and GLR of the lesions were calculated. The elasticity scores of the lesions were also evaluated using the five-point elasticity scoring system. For diagnostic performance, the sensitivity, specificity and receiver operating characteristic (ROC) analysis were obtained.

Results

Seventy lesions were malignant and 123 were benign. Both the FLR and GLR of the lesions were significantly higher in malignant cases than in benign ones (P?P?=?0.009, P?=?0.029, respectively). However, there was no significant difference in the Az value between the FLR and the elasticity score (P?=?0.443).

Conclusion

The FLR yielded better diagnostic performance than GLR in breast lesions; the fatty tissue was better than glandular tissue as the reference normal tissue for calculating strain ratio in breast elastography.

Key Points

? FLR was higher than GLR in both malignant and benign breast lesions. ? Both FLR and GLR were higher in malignant than in benign breast lesions. ? FLR yielded better diagnostic performance than GLR in breast lesions.     

Heat strain evaluation of chemical protective garments

BACKGROUND: The purpose of this study was to compare thermoregulatory and subjective responses of 12 test subjects (10 male, 2 female) wearing 5 different Joint Service Lightweight Integrated Suit Technology (JSLIST) prototype and 3 different currently fielded control chemical/ biological (CB) protective overgarments. METHODS: The overgarments were compared while subjects attempted to complete 100 min of moderate exercise (400 W) in an environmental chamber (35 degrees C/50% rh). Rectal temperature (Tre), skin temperature, heart rate, sweating rate, and test time, as well as subjective symptoms of heat illness were measured. Data were analyzed for times earlier than 100 min because subjects were not usually able to complete the 100-min trials. RESULTS: At 50 min, of the 3 controls, the Army/Air Force Battledress Overgarment (BDO) imposed significantly greater heat strain (indicated by Tre 37.90 degrees C) than the Marine Saratoga (SAR) (Tre 37.68 degrees C) and Navy Chemical Protective Overgarment (CPO) (Tre 37.69 degrees C). The JSLIST prototype garments imposed heat strain (50 min Tre 37.73-37.86 degrees C) as well as subjective perception of heat strain, that ranged between the warmest and coolest controls. CONCLUSIONS: In the environmental and exercise test conditions of this study, we did not find the five JSLIST overgarments to be consistently different from one another. Subjects in the control garments were and felt generally warmer (BDO) or cooler (SAR, CPO) than in the JSLIST prototype garments.     

二维应变新技术及临床应用

应变/应交率成像是近年发展起来的一种无创性定量评价心肌功能的超声技术,具有不受心脏平移和周围心肌牵拉影响的优点。二维应变能计算出组织运动的速度、应变、应变率及旋转角度等参数,且无多普勒应变率成像技术角度依赖,可为观察心肌运动、诊断心肌缺血、定量评价局部心肌功能提供一种全新的方法。     

Physiological strain unique to field hockey

Unique requirements of field hockey include dribbling the ball and moving quickly in a semi-crouched posture. First, the net physiological strain due to dribbling was examined. Seven male hockey players completed a 5 min run on the treadmill at 8 km h-1 and 10 km h-1: subjects also ran at these speeds whilst dribbling a hockey ball. Dribbling increased energy expenditure by 15-16 kJ min-1 above that observed in normal running. Heart rates and perceived exertion were also increased. The posture in dribbling is likely to cause back ache among players: 53% of respondents (n = 81) reported experience of lower back pain. Finally, the shrinkage of spinal length during dribbling was examined. Subjects (n = 7) ran for 7 min on the treadmill whilst dribbling a ball. Shrinkage occurred at a rate of 0.4 mm min-1, which is greater than previously reported for other activities. The peculiar postural requirements of field hockey seem to cause physiological strain and spinal loading in excess of orthodox motion.     

Heat strain during explosive ordnance disposal

Bomb technicians perform their work while encapsulated in explosive ordnance disposal suits. Designed primarily for safety, these suits have an unintended consequence of impairing the body's natural mechanisms for heat dissipation. Consequently, bomb technicians are known to experience symptoms of heat illness while performing their work. This research provides the first field based analysis of heat strain in bomb technicians. Six participants undertook simulated operational tasks across 2 days of variable climate. All subjects demonstrated high levels of heat strain as evidenced by elevated heart rate, core body temperature, and physiological strain index. Participants also reported signs and symptoms associated with heat illness. These results were exacerbated by more intense physical activity despite being undertaken in a cooler environment. The universal experience of heat strain in this sample has significant implications for the health of bomb technicians and additional research examining methods to improve temperature regulation and performance is warranted.