实时谐波灰阶超声造影评价犬前列腺射频消融灶

目的应用实时谐波灰阶超声造影技术观察实验犬前列腺射频消融灶,并与常规二维超声检查、彩色能量多普勒超声检查及病理学结果进行比较,以评估实时谐波灰阶超声造影评价前列腺射频消融灶的有效性。方法对5条犬前列腺两侧叶行射频消融,术后即刻行经直肠二维超声检查、能量多普勒超声检查和超声造影。超声造影下测量消融灶体积,并与病理学标本大体测量的结果相比较。结果常规二维超声在射频消融后即刻无法准确地观测消融灶的范围。彩色能量多普勒超声虽然不能准确评价消融灶的体积,但对消融灶的血流变化比较敏感,能及时反映消融灶血流状态的改变。超声造影则能准确评价消融灶的范围,其测量结果与病理学结果比较没有统计学差异,且超声造影能够实时观察消融灶内部及周边血流灌注的情况。结论常规二维超声和彩色能量多普勒超声能实时反映消融灶回声的变化和血流情况的改变。实时谐波灰阶超声造影技术能准确地评价前列腺射频消融灶的范围。     

超声造影彩色显像评估肾血流灌注的实验研究

目的评价超声造影彩色显像评估肾实质血流灌注的价值。方法20只兔~＇t-N静脉注射超声造影剂。造影前后用二维、彩色多普勒能量显像和彩色多普勒血流显像连续采集肾增强图像。定量分析测定二维及彩色增强显像的视频密度和彩色面积。得到二维显像和彩色谐波能量显像的时间一强度曲线。结果造影后彩色谐波能量图的视频密度为199．27±12．38，彩色增强面积为（82．38±9．92）％，均高于其他组（P〈0．05）。彩色能量谐波造影较二维谐波造影增强的时间长且强度大。结论造影增强彩色显像可有效地观察肾脏血流灌注特征。     

能量多普勒及造影增强超声观察微波凝固治疗兔VX2肝癌疗效的初步研究

目的　应用能量多普勒及超声造影在微波凝固治疗兔VX2 肝癌后进行疗效评价。方法　建立 10个VX2 肝癌模型 ,开腹对VX2 肿瘤行微波辐射 (波长 9mm)治疗 ,每次 60W× 12 0s。微波治疗前后均行二维、能量多普勒及超声造影 (Levovist ,3 0 0mg/ml,0 .3ml/kg)观察 ,取肿瘤标本行病理检查。结果微波治疗即刻二维超声示沿微波天线呈强回声窄带样改变 ,周围呈较宽而均匀的低回声 ,肿瘤边缘变得不清晰。微波治疗后能量多普勒检查 4只VX2 肿瘤结节见血流增强信号 ,而超声造影示 10只VX2 肿瘤结节均可见血流增强信号 ,病理证实为不完全坏死。结论　超声造影能更灵敏地评价微波凝固治疗VX2 肿瘤的疗效 ,残存瘤组织表现为肿瘤内持续造影增强。     

超声血流成像技术对子宫肌瘤经皮微波消融前能量的预测价值

目的探讨超声血流成像技术在子宫肌瘤微波消融前能量预测作用。方法拟行微波消融的子宫肌瘤患者于治疗前行常规彩色多普勒和三维能量多普勒超声成像,进行肌瘤血供分级并计算血管化血流指数(VFI);选取直径5cm以上肌瘤于微波消融术中行单导Tlla电极、微波功率50 W,作用时间300s的定量消融,消融后超声造影测量无灌注区范围作为定量消融范围,比较不同血供分级和VFI大小肌瘤定量消融范围。结果共66个肌瘤入组。按肌瘤血供分级对应VFI大小范围分三组:0~0.999(Ⅰ级)、1~2.699(Ⅱ级)、2.7~7.999(Ⅲ级),肌瘤数分别为26、18、22。相同微波能量时,血供分级高、VFI大者消融范围小,各组间定量消融范围比较及两两比较差异有统计学意义(P0.05)。结论超声血流成像技术可为临床经皮微波消融治疗子宫肌瘤能量预测和术前规划提供指导和参考。     

能量多普勒造影评价微波治疗肝癌效果的应用

目的 探讨能量多普勒造影对微波治疗后肝癌血管的显像效果。方法 15例肝癌（24个病灶）1～2次微波治疗后经外周静脉注射Levovist观察癌内及癌旁造影前后的血流显像，并与病理结果相对照。结果 微波治疗后24个癌灶造影前无一例有血流显示。造影后19个病灶无血流显示者病理为完全性坏死；5个病灶有血流显示（1例瘤内，4例瘤旁），相应部位活检为完全性坏死，追加二次微波治疗，造影后未见血流显像，病理证实为完全坏死。结论 能量多普勒造影是评价微波治疗肝癌疗效的实用性方法之一。     

超声造影、磁共振评价肾射频消融短期效果的实验研究

目的 应用超声造影(CEUS)、磁共振(MRI)观察正常兔肾射频消融灶的影像表现,并与大体病理进行对照,探讨超声造影、MRI在正常肾射频消融效果评估中的价值.方法 10只新西兰大白兔行肾经皮射频消融术,分别在射频术后1d、1周行超声造影及MRI检查,并与大体标本消融灶的测量结果进行比较.结果 在射频消融术后较短时间内(术后1d和1周),超声造影和增强MRI可以清晰地显示肾消融灶的部位、形态及范围,影像表现与大体标本、超声造影与增强MRI测量结果比较,差异均无统计学意义(P＞0.05).结论 超声造影和增强MRI均适用于肾射频消融灶短期情况的观察评价,超声造影可以实时动态地显示消融灶血流灌注的变化.     

超声造影在脑组织微波消融中的实验研究

目的 探讨超声造影在评价动物脑组织微波消融中的应用价值,为临床应用提供实验依据.方法 选取健康家犬17只,以不同微波功率及消融时间组合分别作用于动物脑组织;术后30 min去骨瓣,分别行常规超声及超声造影检查,观察消融灶的边界、范围,比较消融灶内、水肿带区、正常脑组织内的超声造影时间-强度曲线及参数;术后5h取出脑组织,观察消融灶的大体病理及显微病理改变.结果 ①脑组织微波消融成功获得34个消融灶,超声造影所测消融灶范围较常规超声测值小,差异有统计学意义(P =0.000);病理证实超声造影所显示的消融坏死范围更为准确,超声造影无增强区的脑组织完全坏死,常规超声与超声造影所测消融灶范围之间的环形区域为水肿带.②水肿区与正常脑组织的超声造影开始增强时间、达峰时间及峰值强度比较,差异无统计学意义(P值分别为0.992、0.993、0.749).结论 超声造影能实时准确显示脑组织微波消融的坏死范围,并能显示消融灶及周围脑组织的血流灌注情况,可用于评价脑组织微波消融的效果.     

能量多普勒声学造影评价微波凝固治疗VX_2肝癌疗效的实验研究

目的　探讨能量多普勒声学造影对兔VX2 肝癌微波凝固治疗的疗效评价 ,及其对残存瘤组织检查的敏感性与特异性。方法　应用UMC 1型微波治疗仪 ,频率 2 45 0MHz ,16G防粘植入性天线 ,芯线裸露长度为 9mm ,对 10只兔VX2 肿瘤行开腹微波辐射治疗 ,60W× 12 0s。治疗前后均行能量多普勒声学造影 ,灌注 延迟法观察肿瘤结节内血流变化。结果　微波治疗后造影检查 ,6例VX2 肿瘤仅于静脉相观察到稀疏的点状血流 ,2周后病理证实为完全坏死。 4例首次治疗后肿瘤内可见持续血流增强 ,对该区二次微波治疗后 ,3例结节内未见血流 ,1例静脉相边缘有持续血流显示 ,2周后再次行造影检查 ,可见中心及周边血流明显增多 ,病理证实为不完全坏死。结论　能量多普勒声学造影能早期评估微波凝固治疗VX2 肿瘤的疗效 ,并能指导再次治疗的目标区域 ,残存瘤组织表现为肿瘤内持续造影增强     

超声造影评估肝脏肿瘤微波消融边界的研究进展

微波消融（microwave ablation，MWA）以其微创、疗效好等特点已广泛应用于肝脏肿瘤的治疗，而消融未达到安全边界会造成治疗不彻底的后果，容易引起肿瘤复发，因此消融术后评估消融边界（ablation margin，AM）是治疗中不可或缺的环节。而超声造影（contrast-enhanced ultrasound，CEUS）具有经济、实时、无放射性、无肾毒性等优点，可作为评估AM的重要方法。本文就超声造影评估肝脏肿瘤微波消融边界的研究进展做一综述。     

超声引导下经腹射频术治疗子宫腺肌病的近期疗效研究

目的探讨超声引导下经腹射频消融（RFA）微创术治疗子宫腺肌病的近期临床疗效。方法32例子宫腺肌病患者行射频消融术,观察术后1、3、6、10个月的临床症状、超声造影病灶血流灌注、子宫体积、血清血红蛋白（Hb）及卵巢肿瘤相关抗原（CA125）含量的变化。结果术后随访各时间点,患者痛经症状、经量及血块量均较术前明显改善。术后1个月血清CA125水平较术前明显下降（P〈0.05）,超声造影可见消融病灶内未见造影剂灌注。术后3个月血清Hb水平较术前明显升高（P〈0.05）。术后10个月子宫体积进行性缩小,与术前比较差异均具有统计学意义（P〈0.01）。结论超声引导下经腹射频消融微创术治疗子宫腺肌病可以安全有效地灭活异位子宫内膜组织的血管并明显改善患者的临床症状。     

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.