MRI测量肝体积及其临床应用

目的:研究MRI对肝脏体积测量的准确度及其在临床中的应用价值.方法:对30例患者进行MRI肝脏扫描,其中一组8例行原位肝移植术,一组22例,均为肝肿瘤,接受肝右叶切除术.在T2压脂序列上测量全肝或肝右叶体积,将结果与手术后水浸法得出的肝体积结果进行比较.结果:MRI测量全肝及肝右叶平均体积分别为(862.3±199.7)mL、(644.5±122.6)mL,水浸法测得全肝及肝右叶体积分别为(841.3.±156.3)mL、(621.7±115.2)mL.两种方法所测结果经配对t检验无统计学差异(P＞0.05).测量误差平均-8.49%～8.93%.结论:MRI可较准确地测量肝脏体积,具有可靠的临床应用价值.     

猪劈离式原位肝移植动物模型建立及麻醉处理

背景:劈离式原位肝移植技术存在术后胆道并发症发生率高、左内侧叶缺血坏死等问题,为了进一步开展劈离式肝脏移植的研究,需要找到一种适宜的动物,建立稳定的移植及麻醉模型。目的:探讨猪劈离式原位肝移植模型建立及其术中麻醉处理特点。方法:40只健康3月龄猪,体质量25~30kg,在气管插管全麻下进行静脉-静脉转流,供肝沿Taira线劈离,对断面修整后,行原位肝脏移植。结果与结论:手术时间(220±31)min,无肝期(35±6)min。术后肝功能恢复顺利,手术成功率50%,10只动物存活时间均超过48h,无肝期、再灌注期血流动力学波动明显,并伴有代谢性酸中毒;再灌注期血钾升高明显,体温下降明显。结果可见:①猪同种异体原位劈离式肝脏移植模型(沿Taira线)具有操作简便,标准化程度及手术成功率高,重复性和稳定性好的优点,是大动物肝移植系列研究的较理想动物模型。②即使在良好的静脉转流下无肝期、再灌注期血流动力学、内环境变化仍明显,麻醉过程中纠正凝血机制及维持内环境的稳定对手术的成功至关重要。     

基于MRI的动物肝脏脉管分割与三维重建

目的探索基于磁共振成像的肝脏脉管(血管、胆管)三维重建的方法,以显示肝脏中血管、胆管走行立体图像,从而指导劈离式肝脏移植手术.方法综合利用二维图像的多种平滑和分割方法,得到肝实质和肝脉管二维图像序列,并在此基础上三维重建肝实质和肝脉管.结果由MR图像序列可三维重建清晰的肝实质和肝血管立体图像,并且可得到肝叶、段间血管及胆管的走行及相互关系.结论利用MRI和图像分割以及图像三维重建技术指导劈离式肝移植手术,具有重要的临床意义.     

三维超声体积自动测量技术计算兔肝脏体积准确性的实验研究

目的评价三维超声体积自动测量(VOCAL)技术计算兔子肝脏体积的准确性,并探讨不同旋转步长对准确性的影响。方法对30只新西兰健康大白兔肝脏进行三维图像采集,应用VOCAL技术选择30°、15°、9°、6°旋转步长分别计算兔子肝脏体积;随后处死兔,以离体肝脏体积作为对照,比较不同旋转步长计算兔子肝脏体积的准确性。结果 30°、15°、9°、6°4种不同旋转步长所测量肝脏体积分别为(60.31±12.96)cm3、(55.66±10.23)cm3、(55.51±9.76)cm3、(56.02±10.89)cm3,离体肝脏实际体积为(56.33±10.90)cm3;30°测量值与实际体积的差异有统计学意义(P<0.05),15°、9°、6°测值与实际体积的差异无统计学意义(P>0.05),30°、15°、9°、6°旋转步长测量值与实际值的相关系数分别为0.872、0.880、0.915、0.953。结论 15°、9°、6°可作为三维超声测量兔子肝脏体积的合适旋转步长,15°为兼顾准确和简便的最佳选择。     

多层螺旋CT测量肝脏体积在活体肝移植中的应用

目的：研究多层螺旋CT（MSCT）测量肝脏体积及对活体肝移植的应用价值。方法：MSCT扫描26例供体和受体亲体肝移植患者,并对所有病例采用阈值法和层切法对全肝肝叶体积进行测量,测量结果与标准化体积进行对比。结果：MSCT肝脏体积测量的供体和受体平均体积分别为1204.23cm3、1232.4cm3,供体和受体标准化平均体积分别为1207.02cm3、1220.1cm3,2种方法测量结果差异无统计学意义（P>0.05）。结论：MSCT可以准确评价肝脏体积,为活体肝移植术前提供重要依据。     

1例成人多米诺肝移植患者的护理

正目前,供肝的缺乏是限制临床肝移植发展的主要障碍之一。随着肝外科手术的不断完善,人们开展了活体部分肝移植、劈离式肝移植等方法来扩大供肝的来源[1]。近年来出现了一种新型的解决供肝缺乏问题的肝移植术式-多米诺肝移植 ( Domino liver transplantation,D L T ),也称为连续性肝移植 ( Sequential liver transplantation)是指某些需要进行肝移植的疾病中,肝脏仅仅因为遗传缺陷导致全     

改良法构建大鼠减体积肝移植模型

背景:目前有关活体肝移植后肝脏再生的研究较少.在大鼠肝移植实验中不断改进手术方法和技术,提高肝移植成功率是进行大鼠肝移植研究和获得可靠实验数据的基础.目的:验证以改良方法构建减体积肝移植大鼠模型的有效性.方法:选用健康SD大鼠,70对制备减体积肝移植改良前模型,100对制备减体积肝移植改良后模型.供体为雌性,受体为雄性,供体体质量比受体轻10 g左右.改良前方案采用取下全肝后在修肝盆中进行减体积肝移植.改良后方案如下:供体采用单人裸眼操作,在取肝的过程中即进行减体积操作;修肝时将套管柄置于门静脉和肝下下腔静脉的正前方,将幽门静脉结扎点外翻于套管外并置于套管柄的左侧,即肝脏的左侧;将右肾静脉结扎点外翻于套管外并置于套管柄的右侧,即肝脏的右侧;供肝套管完成后用灌注液对门静脉和肝下下腔静脉进行冲洗;然后以左膈静脉为标识点进行7/0无损伤血管缝线吊线;受体采用双人裸眼配合操作,肝上下腔静脉吻合时,左右固定位点采用"8"字形外翻缝合,后壁和前壁分别采用连续吻合,门静脉和肝下下腔静脉采用改良的双袖套法,胆管支撑管法建立大鼠减体积的稳定模型.结果与结论:改良后供体手术时间为(32+9)min,修肝时间为(6±2)min,受体手术时间为(40±3)min,无肝期时间为(14±3)min.移植成功率为92%,移植后3 d生存率为85%,移植后2周生存率83%.与改良前比较,移植后并发症发生率降低(P<0.05),供肝的冷保存时间缩短(P<0.05).提示改良后的大鼠减体积肝移植模型比较稳定,可靠,移植成功率较高,移植后并发症发生率较低,为研究减体积肝移植后肝脏再生提供了有效的改良手段.     

劈离式肝移植一供两受的手术护理配合

肝脏被认为是由具有独立生存能力的 2个部分组成 ,即左半肝及右半肝。左、右半肝各自具有独立完整的门静脉、肝动脉、肝静脉和胆道系统 ,这是实施劈离式肝移植的解剖基础。[1] 劈离式肝移植是指将 1个完整的同种异体供肝 ,按照解剖结构修整分离出 2套各自独立的动脉、静脉及胆道系统 ,分别移植在 2例患者体内。在供肝明显匮乏的情况下 ,劈离式肝移植可挽救更多终末期肝病患者的生命。我院于2 0 0 2年 7月成功实施了国内首例劈离式肝移植手术 ,[2 ] 现将手术护理配合报告如下。1　临床资料1.1　病例简介患者 1,女 ,4 5岁。 2 0 0 0年 7月因肝…     

多层螺旋CT肝脏体积测量及其临床应用价值

目的评价多层螺旋CT肝脏体积测量的准确性和临床应用价值.方法对39例患者进行MSCT肝脏容积扫描,其中肝硬化组13例,5例行原位肝移植术;肝肿瘤组13例,均接受肝右叶切除术;对照组13例.比较采用阈值法及层切法两种方法进行全肝和肝右叶体积测量的结果并与手术结果对比.结果层切法所测全肝及肝右叶平均体积分别为(1269±345)ml、(726±199)ml;阈值法测得全肝及肝右叶体积分别为(1250±346)ml、(713±198)ml.两种方法所测结果无统计学差异.肝右叶切除患者MSCT测量结果与实际肝右叶体积间无统计学差异(P＞0.05).结论MSCT作为评价肝脏体积的有效方法,具有可靠的临床应用价值.     

术中超声在小儿肝脏移植中的应用

目的 研究术中超声(intraoperative Doppler ultrasound,IDUS)在小儿肝移植术中评价移植肝血流的价值.方法 15例患儿在肝移植术中移植肝血管吻合完成及关腹后.应用IDUS测量肝动脉、门静脉及肝静脉血流,并对比研究不同年龄组及术式组间差异.结果 (1)15例患儿移植肝动脉收缩期峰值流速(S),(44.50±26.26)cm/s,舒张期末流速(D),(14.29±11.34)cm/s;门静脉直径(8.4±1.2)mm,流速(36.1 2±16.57)cm/s;肝静脉直径(6.5±1.2)mm,流速(38.97±14.08)cm/s.(2)小儿组(年龄≥1岁)肝动脉、门静脉血流速度高于婴儿组(年龄<1岁,P1=0.003,P2=0.001,P3=0.022);而婴儿组肝静脉流速高于小儿组(P=0.026).(3)活体肝移植组和劈裂式肝移植组血流速度差异无显著的统计学意义.结论 在小儿肝移植术中超声可及时发现异常血流,尽早处理,有利于患儿预后,在实时监测移植肝血流动力学状态方面具有不可替代的作用.     

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.