肝移植术前门静脉系统栓子超声造影参数成像的临床应用

目的 探讨CEUS参数成像在诊断及鉴别诊断肝移植术前门脉系统栓子中的临床应用价值。方法 回顾性分析接受CEUS检查并经临床或病理证实的41例肝移植术前门脉系统栓子患者,观察造影剂灌注模式,并利用sonoliver CAP定量分析,以门静脉栓子与周围肝实质的增强水平差值为参数进行动态血管模型(DVP)参数成像构建。结果 门静脉瘤栓动脉期呈快速增强,门脉期及延迟期明显消退。门静脉瘤栓的上升时间、达峰时间、平均渡越时间分别快于周围肝实质,差异均有统计学意义(P均＜0.01);门静脉瘤栓的峰值强度高于周围肝实质,差异有统计学意义(P=0.001)。门静脉血栓三期均无造影剂灌注,各参数值均为0。结论 CEUS参数成像能直观反映门脉系统栓子与周围肝实质间灌注差异,鉴别栓子性质。     

二维及彩色多普勒超声诊断新生儿缺氧缺血性脑病

目的 评价二维超声及彩色多普勒超声诊断新生儿缺氧缺血性脑病(HIE)的价值。方法 对85名日龄3~15天的新生儿行颅脑二维及彩色多普勒超声检查,检出39例新生儿HIE,分为轻度、中度及重度HIE;另选正常对照组10名,对比分析HIE患儿的超声特点及大脑中动脉(MCA)的血流参数。结果 轻度HIE超声表现为脑实质回声增强,回声低于脉络丛;中度HIE表现为脑实质回声强度接近脉络丛回声,脑室正常或轻度扩张;重度HIE表现为脑实质弥漫性回声增强,超过脉络丛回声强度,脑实质结构模糊、不清晰。随访示22例HIE患儿7~10天后脑实质回声接近正常;14例HIE患儿10天后脑实质回声仍增强、粗糙,提示可能存在脑白质损伤;3例放弃治疗而失访。与正常对照组比较,不同程度HIE患儿双侧MCA舒张期血流速度差异均有统计学意义(P<0.05)。HIE的严重程度与左侧MCA的舒张期血流速度、阻力指数,右侧MCA的舒张期血流速度、收缩期血流速度、搏动指数及阻力指数相关。不同程度HIE之间MCA的血流参数差异无统计学意义(P>0.05)。结论 颅脑超声检查可较清晰显示新生儿HIE颅内结构及侧脑室变化;结合MCA血流动力学参数,可对新生儿HIE的病情及预后进行评估。     

超声造影评价颈动脉斑块类型与斑块内新生血管关系

目的 采用灰阶谐波CEUS评价斑块内新生血管与常规超声显示斑块类型之间的关系。方法 收集98例颈动脉粥样硬化患者共113个斑块,根据回声特征及形态学分为均质、非均质及溃疡型斑块,均质斑块又分为低回声、等回声及强回声斑块。分析斑块回声特征与造影增强模式特点。结果 CEUS显示低回声斑块新生血管检出率明显高于等回声(χ²=10.64,P=0.001)、强回声(χ²=18.62,P<0.001)及溃疡型斑块(χ²=7.38,P=0.007);但低回声与非均质斑块新生血管检出率的差异无统计学意义(χ²=2.20,P=0.138)。增强的64个斑块中,46个(46/64,71.88%)斑块表现为由管壁外膜向斑块内增强,其中44个弥漫性增强,2个为束状增强;18个(18/64,28.13%)斑块表现为由管腔向斑块内蔓延的稀疏增强。各类型斑块间CEUS增强模式的差异无统计学意义(P>0.05)。结论 CEUS可提供更多有关于斑块内新生血管的信息,有助于进一步判断斑块稳定性。     

超声造影定量评价动脉粥样硬化斑块新生血管及其与组织病理学的相关性

目的 应用CEUS技术定量评价动脉粥样硬化斑块增强强度及其与病理染色所示的新生血管密度的相关性。方法 选取新西兰白兔25只,高脂饲养4周后,以球囊扩张腹主动脉,再高脂饲养16周,建立动脉粥样硬化模型;行常规超声及CEUS检查,观察不同类型斑块的增强情况,应用时间-强度曲线定量分析动脉粥样硬化斑块的增强强度,以CD31染色观察斑块内新生血管的密度。应用非配对t检验比较软斑与硬斑造影强度及新生血管密度的差异;Pearson相关分析动脉粥样硬化斑块CEUS增强强度与斑块新生血管密度的相关性。结果 二维超声诊断为软斑的斑块在CEUS中的增强强度明显高于硬斑(P<0.05);软斑的新生血管密度明显高于硬斑(P<0.05);斑块内新生血管密度与斑块造影增强强度存在明显相关性(r=0.75,P<0.001),与斑块增强强度/管腔增强强度亦存在明显相关性(r=0.68,P<0.001)。结论 CEUS可定量评价兔动脉粥样硬化斑块的增强情况;斑块增强强度与斑块内新生血管密度具有良好的相关性。     

超声造影对肝良性占位病变的鉴别诊断价值

目的 通过对肝脏良性占位病变在超声造影中的增强方式,增强时间,以及时间-强度曲线分析,探讨超声造影对肝良性占位病变中的血流灌注特点以及在肝肿瘤鉴别诊断中的应用价值.方法 对65例经手术或超声引导穿刺活检病理确诊的肝良性占位(血管瘤34例,局灶性增生结节6例,肝硬化增生结节12例,肝腺瘤5例,肝脓肿8例),术前进行超声造影与术后病理结果进行回顾性比较分析.结果 肝血管瘤表现为周边结节状增强及絮团状逐渐向心性增强方式,局灶性结节增生早期动脉相表现为"轮辐状"增强;肝硬化增生结节造影表现与周围肝组织基本一致;肝腺瘤显示为动脉相整体快速增强,延迟相显示为高增强;肝脓肿造影后病灶内呈网格状增强,出现大小不等的无回声区呈融合状,与周围肝组织分界清晰.增强时间及强度,肝血管瘤呈慢进慢出低强度,肝局灶性结节增生呈快进慢出高强度,肝硬化增生结节与周围肝组织同步显影等强度,肝腺瘤呈快进慢出低强度,肝脓肿呈快进快出低强度.结论 实时超声造影可显示大多数肝良性占位病变的不同灌注特点,通过时间-强度曲线分析可定量检测病灶在造影过程中随时间不同增强强度的变化,有助于对肝良性占位病变的鉴别诊断.     

超声造影鉴别诊断乳腺良恶性肿瘤

目的 探讨超声造影(CEUS)鉴别诊断乳腺良恶性肿瘤的应用价值。方法 纳入277例乳腺肿瘤患者,均行常规超声(BUS)及CEUS检查,并与病理结果进行对照,对BUS及CEUS各观察指标进行Logistic回归分析,比较BUS与CEUS鉴别诊断乳腺良恶性肿瘤的效能。结果 277例患者中,良性病变184例(良性组),恶性病变93例(恶性组)。Logistic回归分析显示,BUS诊断恶性肿瘤的危险指标为中等血供、非平行生长、血供丰富及边界模糊,相对危险度分别为5.17、4.84、3.39、3.04;CEUS为离心性增强、向心性增强、肿瘤形状不规则、造影剂分布不均、增强后范围增大,相对危险度分别为13.36、4.58、4.07、3.28、2.36。BUS诊断乳腺肿瘤的准确率为81.59%(226/277),CEUS为88.09%(244/277),二者差异有统计学意义(χ²=1.012, P<0.001)。结论 采用CEUS鉴别诊断乳腺良恶性肿瘤的准确率较高,其在乳腺局灶性病变的定性诊断中具有一定的应用价值。     

经皮超声造影诊断乳腺癌前哨淋巴结转移

目的 探讨经皮CEUS诊断乳腺癌前哨淋巴结（SLN）转移的价值。方法 对79例乳腺癌患者行二维及彩色多普勒超声检查,并行前哨淋巴结经皮CEUS,采用目测法分析造影模式,利用时间-强度曲线获得相关参数,并将CEUS结果与病理进行对比分析。结果 79例中,32例存在前哨淋巴结转移（转移组）,47例无转移（无转移组）。转移组前哨淋巴结增强模式以不均匀增强为主,无转移组以均匀增强为主（P<0.001）;转移组与无转移组灌注强度差、达峰强度及达峰平均强度的差异均有统计学意义（P均<0.05）,而造影剂到达时间、达峰时间及上升斜率差异均无统计学意义（P均>0.05）。结论 经皮CEUS对预测乳腺癌SLN转移有一定临床应用价值。     

肝局灶性病变超声造影与增强CT和MRI表现的比较

目的 比较肝局灶性病变CEUS与增强CT(CECT)、增强MRI(CEMRI)表现的异同,并分析差异原因。方法 回顾性分析我院70例肝局灶性病变患者的影像资料,共75个病灶,包括肝细胞癌39个,转移性肝癌6个,胆管细胞癌6个,局灶性结节性增生6个,肝硬化结节5个,肝血管瘤4个,坏死结节4个,其他5个。阅片医师对各时相增强水平、增强类型、有无新发病灶等进行评价。采用Kappa检验评估CEUS与CECT/CEMRI表现及医师阅片结果间的一致性,并分析不一致的影像表现。结果 CEUS与CECT/CEMRI在病灶是否存在确切无增强的坏死或瘢痕区域方面一致性最高(Kappa=0.68);在门静脉期病灶相对于周围肝实质的主要增强水平方面一致性最低(Kappa=0.48)。44.23%(23/52)的恶性病灶及21.74%(5/23)良性病灶的CEUS与CECT/CEMRI表现不完全一致。结论 CEUS与CECT/CEMRI各时相表现一致性较好,差异性表现多集中于恶性病变。病灶影像表现存在差异的原因可能与对比剂不同及病理组织特征等有关。     

超声造影评价大鼠肝纤维化分期与肾血流灌注的相关性

目的 分析CEUS技术评价大鼠肝纤维化分期与肾血流灌注的相关性。方法 健康雄性Wistor大鼠50只,随机选取44只,经硫代乙酰胺诱导为肝纤维化模型(肝纤维化组),6只作为对照组。于造模后第4、8、12周分别选取12只肝纤维化组大鼠及2只对照组大鼠行CEUS检查。比较各期(S0~S4)肝纤维化大鼠肾血流灌注情况及时间-强度曲线检测指标变化,并进行统计学分析。结果 与其他各期和对照组比较,S4期大鼠肾皮质血流时间-强度曲线峰值强度减低、达峰时间延长、曲线下面积减小(P均<0.05)。峰值强度、曲线下面积与肝纤维化分期呈负相关(P均<0.01);达峰时间与肝纤维化分期呈正相关(P<0.01)。结论 CEUS结合时间-强度曲线可定量分析不同程度肝纤维化大鼠肾血流灌注情况。肾皮质CEUS参数变化与大鼠肝纤维化分期密切相关。     

大鼠局灶性脑创伤早期的DTI和1H-MRS的特征

目的 探讨大鼠局灶性创伤性脑损伤（TBI）早期创伤灶周围区的DTI和¹H-MRS参数随时间的变化。方法 健康雄性SD大鼠24只,随机分为创伤组16只、对照组8只。创伤组制作大鼠液压冲击脑皮质损伤动物模型,于两组模型制作后1、3、5 h行DTI和¹H-MRS扫描,分别测量伤侧病灶周围区及健侧半球对应部位的DTI参数ADC值、FA值和¹H-MRS参数N-乙酰天门冬氨（NAA）/肌酸（Cr）、胆碱类化合物（Cho）/Cr和乳酸（Lac）/Cr,对照组测量双侧大脑半球相应部位各指标,并进行统计学分析。结果 创伤组伤后1、3、5h创伤侧病灶周围区与健侧对应部位比较,ADC值均降低、FA值均升高（P均<0.05）;NAA/Cr均降低、Lac/Cr均升高（P均<0.05）,Cho/Cr差异无统计学意义（P均>0.05）。创伤灶周围区伤后3h较1h的ADC值降低（P<0.001）、FA值升高（P=0.002）,伤后5 h较3 h的ADC值升高（P=0.005）、FA值降低（P=0.012）。对照组双侧大脑半球各时间点各指标差异均无统计学意义（P均>0.05）。结论 大鼠脑皮质局灶性损伤后1~5h创伤灶周围区存在微观结构及代谢变化,创伤灶周围区的继发性脑损伤于伤后1h已发生,而伤后3h可能有所加重。     

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.