超声造影在肝移植术后血管源性并发症中的应用

目的探讨超声造影在检测肝移植术后血管源性并发症中的应用价值。方法对肝移植术后经彩色多普勒血流显像检查疑肝血管血流异常患者行超声造影检查，观察肝动脉、门静脉、下腔静脉及肝实质的血流灌注，对其中29例经数字减影血管造影（DSA）或CT血管造影（CTA）／MR血管造影（MRA）证实的病例进行分析。结果术后血管源性并发症患者28例，其中肝动脉狭窄22例，肝动脉血栓闭塞3例（肝动脉血栓闭塞合并肝梗死2例），门静脉狭窄2例，下腔静脉狭窄1例，另1例为肝门部血肿并肝动脉、门静脉受压狭窄。超声造影可明确诊断肝动脉血栓闭塞，显示肝动脉、门静脉及下腔静脉狭窄，与DSA或CTA／MRA结果符合率分别为100％（3／3）、90．9％（20／22）、100％（2／2）及100％（1／1）。结论超声造影对肝移植术后血管源性并发症的诊断具有较高的准确率，对指导临床诊断及治疗具有重要的临床应用价值。     

彩色多普勒及超声造影检测肝移植术后肝动脉并发症的应用

目的 评价彩色多普勒血流显像（CDFI）和超声造影在检测肝移植术后肝动脉并发症中的应用价值并对两者进行比较。 方法 CDFI检查肝移植术后患者158例共267人次，观察肝动脉有无血流显示、血流峰值、加速度时间、阻力指数、有无湍流及其峰值。对33例CDFI可疑异常者，用SonoVue及实时超声造影匹配成像技术行超声造影，观察肝动脉及肝实质的血流灌注。 结果 19例经DSA和／或CT血管造影（CTA）证实，其中肝动脉狭窄17例，血栓闭塞2例。17例狭窄均有血流参数异常，但CDFI不能判断狭窄部位及程度；2例血栓闭塞者动脉血流难以显示，不能肯定诊断。超声造影可明确诊断血栓闭塞，显示狭窄部位及其程度，与DSA和／或CTA结果符合率分别为100％（2／2）、94．1％（16／17）和88．2％（15／17）。 结论 CDFI与超声造影互为补充，有利于提高肝移植术后肝动脉并发症的诊断准确性。     

超声造影在诊断儿童移植肝动脉闭塞中的作用

目的探讨超声造影诊断儿童肝移植术后肝动脉闭塞（HAO）的效能并总结进一步常规超声随访中HAO相关并发症（肝内坏死灶和胆道并发症）的发生率。 方法回顾性选取2013年6月至2019年6月首都医科大学附属北京友谊医院肝移植中心633例肝移植患儿的资料,术后常规超声可疑HAO则行超声造影检查,采用四格表分析超声造影诊断HAO的准确性、敏感度、特异度,HAO的确诊标准包括手术证实、数字减影血管造影（DSA）/计算机断层扫描血管造影（CTA）和随访。另外,总结进一步常规超声随访中HAO相关并发症（肝内坏死灶及胆道并发症）的发生率。 结果共42例患儿术后常规超声可疑HAO行超声造影检查,经确诊标准共诊断HAO患儿33例,其中1例为晚发（发生在肝移植术后5个月）。超声造影诊断34例HAO,其中有1例在随后的DSA检查中提示为肝动脉吻合口部分血栓形成,除外动脉闭塞;超声造影诊断肝动脉正常6例,在随访中也均正常;超声造影诊断肝动脉狭窄2例,随后由CTA检查证实,予以剔除。超声造影诊断HAO的准确性为97.5%（39/40）,敏感度为100%（33/33）,特异度为85.7%（6/7）。常规超声观察HAO后侧支循环形成的时间为闭塞后11（10,14）d,结合超声及其他影像学检查（CT/MRI）,33例HAO患儿中,出现肝内缺血坏死灶15例（45.5%）、胆汁瘤5例（15.1%）、胆漏1例（3.0%）、坏死性胆管炎9例（27.3%）、单纯肝内三级胆管扩张2例（6.1%）。 结论超声造影诊断儿童肝移植术后HAO的准确性和敏感度很高,可以比较准确地评价肝动脉的情况,当超声造影发现肝动脉正常时,可以避免患者进行不必要的DSA检查,但当超声造影提示HAO时,需要行DSA验证以避免不必要的开腹探查。另外,超声造影在HAO相关并发症的随访中也具有重要作用。     

三维超声造影评价肝动脉解剖分型的价值

目的探讨三维超声造影评价肝动脉解剖分型的应用价值。方法对10例上腹部肿瘤患者和20例拟捐献供肝的活体肝移植供体的肝脏行二维超声造影和三维超声造影检查。肝动脉解剖分型参照Michels分型标准,以CTA/MRA/DSA/手术为对照,比较二维超声造影与三维超声造影判断肝动脉解剖分型的符合率。结果二维超声造影与三维超声造影判断肝动脉解剖分型的总符合率分别为40.0%(12/30)和83.3%(25/30),两者之间的差异有统计学意义(P=0.000)。其中对于正常解剖类型,二维超声造影与三维超声造影判断符合率分别为40.9%(9/22)和90.9%(20/22),两者之间的差异有统计学意义(P=0.000);对具有解剖变异类型病例,二维超声造影与三维超声造影判断符合率分别为37.5%(3/8)和62.5%(5/8),两者之间的差异无统计学意义(P=0.196)。结论三维超声造影是评价肝动脉解剖结构及变异的新方法,可能成为CTA、MRA、DSA等的重要补充。     

超声造影诊断肝移植术后肝动脉狭窄

目的 探讨超声造影(CEUS)对肝移植术后肝动脉狭窄的诊断价值.方法 对50例原位肝移植术后临床及超声怀疑肝动脉狭窄的受体行CEUS检查,以数字减影血管造影(DSA)、计算机断层成像血管造影(CTA)或临床+超声随访为参考标准.两名阅读者在不知道参考标准结果的情况下对CEUS图像进行评估,评估内容包括肝动脉狭窄程度(轻度,狭窄＜50%;中度,狭窄50%～75%;重度,狭窄＞75%)、狭窄类型(单发、多发)以及狭窄部位,中度和重度狭窄定义为有临床意义的肝动脉狭窄.结果 CTA或DSA诊断肝动脉狭窄39例,另8例经CTA证实为轻度或无狭窄,3例经临床+超声随访证实肝动脉无明显狭窄.CEUS诊断有临床意义的肝动脉狭窄38例(重度狭窄11例,中度狭窄27例),CEUS纠正彩色多普勒超声上的假阳性病例9例(9/50,18.0%),CEUS诊断肝动脉狭窄的准确性、敏感性、特异性、阳性预测值和阴性预测值分别为90.0%、92.3%、81.8%、94.7%和75.0%.结论 CEUS是一种无创、准确诊断肝移植术后肝动脉狭窄的方法,CEUS能准确评估肝动脉的狭窄程度、狭窄类型和狭窄部位,为临床处理提供重要参考信息.     

实时超声造影在肝移植术后门静脉并发症诊断中的应用

目的探讨低机械指数实时超声造影在肝移植术后门静脉并发症诊断中的价值。 方法317例肝移植术后患者进行门静脉彩色多普勒血流显像（CDFI）检查，对其中20例门静脉显像异常的患者，采用造影剂SonoVue和脉冲反向谐波技术进行低机械指数实时超声造影。并与CT血管成像（CTA）结果进行比较。 结果肝移植术后门静脉血栓发生率为2．8％，门静脉狭窄为1．3％。CDFI诊断门静脉血栓与CTA的符合率为61．5％，超声造影为88．9％（P〈0．01）；CDFI诊断门静脉狭窄与CTA的符合率为57．1%，超声造影为100％（P〈0．01）。 结论低机械指数实时超声造影可提高肝移植术后门静脉并发症的诊断能力，其诊断价值与CT血管成像相当。     

超声造影对肝移植术后血管并发症的诊断价值

目的探讨超声造影技术在肝移植术后血管并发症诊断中的临床价值。方法 2005年5月2009年12月对肝移植术后彩色多普勒（CDFI）检查疑有血管并发症的患者44例,行超声造影检查,重点观察可疑血管的增强情况。后全部经数字减影血管造影（DSA）或CT血管成像（CTA）证实诊断。结果超声造影检查发现血管并发症34例,其余10例正常。超声造影与DSA/CTA的诊断结果相一致。其诊断准确率远远大于CDFI。结论超声造影技术操作方便,检查时间短,无放射性,可重复性强,安全性高,定位准确,诊断率高,在肝移植术后血管并发症的诊断中具有重要的临床价值。     

超声造影、术中超声在肝移植术后血管并发症中的应用

目的探讨超声造影、术中超声在肝移植术后血管并发症中的诊断价值。方法对CDFI检查疑有肝动脉、门静脉及下腔静脉狭窄或血栓形成的9例患者进行超声造影检查,对疑有门静脉血栓的3例患者进行术中超声检查;检查结果与数字减影血管造影(DSA)进行对照分析。结果超声造影提示门静脉血栓形成3例,并经术中超声检查证实肝动脉血栓形成3例,下腔静脉狭窄1例,均经DSA证实。另2例超声造影提示肝动脉未见明显异常的患者中,1例DSA诊断为肝动脉狭窄,1例肝动脉无明显异常;超声造影诊断符合(7/9)。结论超声造影可确诊门静脉、肝动脉血栓,但对准确诊断肝动脉狭窄仍有一定困难。     

超声造影诊断肝移植术后早期肝动脉血栓1例

早期肝动脉血栓形成是肝移植术后严重的血管并发症,是导致患者肝功能衰竭既而死亡的重要原因。肝动脉血管造影（以下简称DSA）是诊断肝动脉血栓的金标准,但条件限制其广泛开展。超声造影无创、便捷、无肝肾毒性,重复性佳等特点,其在诊断早期肝动脉血栓形成中有重要意义。本文报道一例肝移植术后早期肝动脉血栓形成患者,通过早期肝脏超声造影提示肝动脉血栓形成,进一步通过DSA明确诊断,继而动脉溶栓得到及时救治,为临床医生及时进行对症治疗争取了关键时间并改善患者预后。本文目的旨在探讨超声造影在诊断肝移植术后早期动脉血栓形成中的应用价值。     

超声造影评价肝移植术后肝动脉并发症伴侧支形成

目的分析总结肝移植术后肝动脉并发症伴侧支形成超声造影(CEUS)表现,探讨CEUS评价肝移植术后肝动脉并发症伴侧支形成的价值.方法2004年4月至2011年12月中山大学附属第三医院肝移植中心所有肝移植术后常规超声或临床表现疑似肝动脉并发症行CEUS检查、并行数字减影血管造影(DSA)检查和(或)CT+CT血管成像(CTA)证实有及无肝动脉侧支形成患者30例.回顾性分析比较肝动脉并发症伴侧支与无侧支患者肝动脉 CEUS表现.结果30例肝移植患者中,11例CT+CTA和(或)DSA检查证实肝动脉有侧支,19例DSA检查证实肝动脉无侧支.肝动脉有侧支患者肝动脉并发症诊断时间晚于肝动脉无侧支患者[304 d(144~1917 d) vs 47 d(5~232 d), U=20,P<0.01].11例肝动脉有侧支患者均有肝动脉并发症,且以肝动脉血栓多见(9/11,81.8%);而19例肝动脉无侧支患者肝动脉并发症以肝动脉狭窄多见(15/19,78.9%),有1例患者无肝动脉并发症;肝动脉有侧支和无侧支患者肝动脉并发症类型差异有统计学意义(Fisher 精确概率法,P =0.001).肝动脉有侧支患者临床表现多平稳,但常规超声检查发现多数病例胆管异常(10/11).肝动脉侧支CEUS表现有一定特征:(1)肝固有动脉多不能显示(10/11);(2)肝门部多条细小迂曲的侧支动脉聚集,呈网状(5/11)或片状增强(6/11),伴细条状增强(2/11).肝动脉无侧支患者除了3例肝动脉血栓外,肝固有动脉均可见显示,肝门部均未见除肝动脉以外的其他动脉.结论肝移植术后肝动脉并发症伴侧支形成CEUS表现具有一定特点,CEUS有可能成为诊断肝移植术后肝动脉并发症伴侧支形成的新方法.     

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.