剪切波弹性成像技术在评估常见病因肝硬化及其结节中的临床应用

目的探讨剪切波弹性成像(SWE)技术在评估常见病因肝硬化及肝硬化结节中的应用价值。方法确诊为肝硬化代偿期的患者129例,按病因将其分为乙肝后、酒精性和自免性肝硬化组,比较各组及三组两两之间杨氏模量值的差异;根据高频超声判断肝脏有无结节将其分为非结节性和结节性肝硬化组,比较两组间杨氏模量值的差异及病因构成比是否不同。结果乙肝后、自免性和酒精性肝硬化组杨氏模量值依次升高,组间差异有统计学意义(F=54.77,P0.01),酒精性肝硬化组肝脏杨氏模量值与乙肝后及自免性肝硬化组比较差异均有统计学意义(q=14.79、7.55,P均0.01),但乙肝后与自免性肝硬化组比较差异无统计学意义(q=2.54,P0.05)。非结节性与结节性肝硬化组的杨氏模量值差异有统计学意义(t=3.33,P0.05);且两组病因类型构成比不同,并有统计学意义(2χ=25.49,P0.005)。结论 SWE技术对评估和鉴别不同原因引起的肝硬化有一定价值,结节性肝硬化组弹性值低于非结节性肝硬化组。     

正常成人腮腺及颌下腺实时剪切波弹性成像的研究

目的:探讨实时剪切波弹性成像(Shear wave elastography,SWE)检测腮腺及颌下腺硬度的可行性,建立正常成人杨氏模量的参考值范围.方法:对820名健康成人进行腮腺及颌下腺实时剪切波弹性成像检查,比较左右两侧及不同性别、年龄组之间杨氏模量值的差异.结果:左右两侧腮腺及颌下腺杨氏模量值差异均无统计学意义(P＞0.05).不同性别间腮腺杨氏模量值差异有统计学意义(P＜0.05);不同性别间颌下腺杨氏模量值差异无统计学意义(P＞0.05).不同年龄组的腮腺及颌下腺杨氏模量值差异均无统计学意义(P＞0.05).结论:实时剪切波弹性成像可用于评估腮腺及颌下腺的硬度,为疾病的鉴别诊断提供有价值的信息.     

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。     

不同体位及部位对实时剪切波弹性成像技术对正常肾脏的影响

目的探讨不同体位及部位对实时剪切波弹性成像技术(SWE)检测正常肾脏的影响。方法选取健康志愿者70例,比较受检者俯卧位下极双肾杨氏模量值及右肾不同体位、部位、性别、年龄组、体质量指数、取样框大小及左侧卧位肝脏遮挡与否杨氏模量值的影响。结果俯卧位下极双肾肾脏杨氏模量值比较差异无统计学意义(P0.05);不同体位、部位肾脏杨氏模量值比较差异有统计学意义(P0.01),左侧卧位中部肾脏杨氏模量值高于其他三组,差异有统计学意义(P0.01)。不同性别、年龄组、体质量指数、Q-box直径及左侧卧位肝脏遮挡与否各组比较差异无统计学差异(P0.05)。结论实时剪切波弹性成像技术检测肾脏弹性受体位、部位影响,左侧卧位中部肾脏弹性测值较高。     

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。     

剪切波弹性成像技术测量肝脏弹性的影响因素分析

目的分析剪切波弹性成像（SWE）技术测量肝脏弹性的影响因素。方法选取2013年9至12月中国医科大学附属第一医院常规肝脏超声检查正常的健康志愿者共130名。采用SWE技术测量不同性别、年龄段、体位、呼吸时相、测量直径时受检者肝脏杨氏模量值,并采用t检验进行比较。肝脏杨氏模量值与年龄的关系分析采用Pearson相关分析。结果同一体位、同一呼吸时相、不同测量直径,同一体位、同一测量直径、不同呼吸时相受检者肝脏杨氏模量值差异均无统计学意义;同一呼吸时相、同一测量直径、不同体位受检者肝脏杨氏模量值差异有统计学意义（t值分别为18.88、18.97、18.82、18.94,P均〈0.05）。呼气末测量直径为10 mm时,无论平卧位还是左侧卧位,同一体位男性受检者肝脏杨氏模量值均略高于女性受检者肝脏杨氏模量值,但差异均无统计学意义。呼气末测量直径为10 mm时,无论平卧位还是左侧卧位,同一体位青年组（20-39岁）、中年组（40-60岁）、老年组（〉60岁）受检者肝脏杨氏模量值均依次增高,但仅青年组与老年组受检者肝脏杨氏模量值差异有统计学意义（t=-3.359、-3.397,P均〈0.05）。Pearson相关分析结果显示,呼气末测量直径为10 mm时,受检者平卧位、左侧卧位肝脏杨氏模量值均与年龄呈正相关（r=0.458、0.370,P均〈0.05）。结论运用SWE技术测量肝脏弹性时,受检者呼吸时相、性别及测量直径对肝脏弹性测量无显著影响,但受检者的体位及年龄影响肝脏弹性测量。     

剪切波弹性成像技术评估颈动脉斑块硬度

目的探讨超声剪切波弹性成像(SWE)新技术定量评价颈动脉粥样硬化斑块硬度的价值。方法 116例颈动脉粥样斑块患者中,常规超声发现颈动脉粥样硬化斑块174处,将其分为软斑块、混合性斑块及钙化斑块;观察不同类型斑块的剪切波弹性图像特点并计算斑块的杨氏模量值。结果二维超声发现软斑块59处,混合性斑块72处,钙化斑块43处。剪切波超声弹性图像中,软斑块显示为蓝色,钙化斑块显示为红色,混合性斑块图像红蓝相间,颜色混杂。钙化斑块组的平均、最小、最大弹性模量值分别为(84.42±9.67)k Pa、(74.03±8.36)k Pa和(102.51±11.32)k Pa,混合性斑块组分别为(48.27±8.61)k Pa、(34.79±9.82)k Pa和(67.04±8.91)k Pa,软斑块组分别为(28.73±6.54)k Pa、(12.13±5.71)k Pa和(34.39±9.25)k Pa,钙化斑块组的平均、最小和最大杨氏模量均高于混合性斑块组和软斑块组,差异均有统计学意义(P均0.01);混合性斑块组高于软斑块组,差异均有统计学意义(P0.05,P0.01,P0.05)。结论不同类型斑块的弹性图像表现及杨氏模量值不同,超声剪切波弹性成像技术可用于评价颈动脉斑块硬度。     

剪切波弹性成像评价鼻咽癌放疗对胸锁乳突肌的影响

目的探讨剪切波弹性成像(SWE)评价鼻咽癌(NPC)放疗对胸锁乳突肌(SCM)的影响,观察放疗前、放疗期间及放疗结束后常规超声表现及其弹性值变化。方法选取病理确诊的NPC患者40例,对所有患者于放疗前(S0)、放疗后4周(S1)、放疗后6周(S2)、放疗结束后3个月(S3)、放疗结束后6个月(S4)分别行超声检查,常规超声观察SCM的肌纤维纹理及内部回声,然后行SWE检查测量其杨氏模量值,比较五组间SCM杨氏模量值的差异。结果 S0、S1、S2、S3、S4五组相比,其肌纤维纹理及内部回声之间差异具有统计学意义(P0.05);S0、S1、S2、S3、S4五组比较杨氏模量值存在统计学意义(P0.05);各放疗阶段左、右侧SCM杨氏模量值之间差异无统计学意义(P0.05)。结论 SWE可用来评估放疗前后SCM纤维化程度的变化,为临床判断及随访病情变化提供依据。     

实时剪切波弹性成像定量评价IgAN的相关研究

目的探讨实时剪切波弹性成像(SWE)技术定量评价IgAN的病理基础及相关研究。方法对IgAN (IgAN)患者及同期健康志愿者(对照组)进行肾弹性成像,前者检查后立即进行肾活检病理学检查,根据Lee分级法将其分为5组,比较各组肾皮质杨氏模量值的差别及与病理改变的关系。结果 (1)LeeⅠ级组与Ⅱ级组(合并为轻度组)、Ⅳ级组及Ⅴ级组(合并为重度组)之间两两比较,差异没有统计学意义(P0.05);其余各组两两比较,差异均具有统计学意义(P0.05)。(2)应用SWE技术区分IgAN各组的ROC曲线下面积、诊断界值、灵敏度、特异度。结论 SWE技术可以作为一种定量评估IgAN的无创检查方法,有助于区分其程度,但对LeeⅠ级与Ⅱ级、Ⅳ级及Ⅴ级的区分仍困难。     

实时剪切波弹性成像测量女性耻骨直肠肌杨氏模量值

目的比较未育及已育初产妇耻骨直肠肌(PR)静息及最大收缩状态下的杨氏模量值差异。方法未育女性73例(未育组),已育初产妇45例(产后1~6年,已育组),利用剪切波弹性成像(SWE)分别在静息及最大收缩状态下测量PR前部、中部及后部的杨氏模量值,并计算差值,比较两组的差异。结果未育组及已育组双侧PR各部最大收缩状态下的杨氏模量值均较静息状态下增大(P均<0.01)。未育组静息及最大收缩状态下PR各部的杨氏模量值及各部收缩前后变化差值与已育组比较,差异均无统计学意义(P均>0.05)。结论 SWE可以定量评估耻骨直肠肌的弹性功能。未育及已育初产妇PR最大收缩状态下的杨氏模量值均较静息状态下大。在静息状态下、最大收缩状态下及收缩前后杨氏模量变化差值,已育初产妇与未育女性的杨氏模量值无差异,分娩对耻骨直肠肌弹性的影响不大。     

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.