肝癌血管形态及其血流动力学的彩色多普勒超声研究

目的应用彩色多普勒超声研究肝癌的肿瘤血管形态学及血流动力学特点。方法采用彩色多普勒血流显像(CDFI)及彩色多普勒能量图(CDE)观察120个肝癌肿块的血供情况,记录血管形态及其分支情况,测量病变周边及内部动脉血流的收缩期峰值流速(PS)、阻力指数(RI)。结果120个肿块中,5 cm≤直径≤10 cm组肿块的CDFI及CDE显示异常形态血管及分支数最多。肝癌肿块血供越丰富,其肿瘤血管内血流速度越快,肿瘤血管不同形态中,PS值以粗细不均血管条状和扭曲血管最高,血管湖组最低;而RI在血管湖处最高,平均为0.83,与其余三组间比较差异有显著性意义(P<0.05)。异常分级方式的肿瘤血管中,在动静脉瘘处测及最高PS值为232 cm/s,网状型PS值最低;RI测值中,动静脉瘘处最低,平均为0.49,与其余三组间比较差异有显著性意义(P<0.05)。结论彩色多普勒超声能够较清晰地显示肝癌的肿瘤血管的形态和分级方式使其血流参数值发生相应的变化。     

二维及彩色多普勒血流显像诊断乳腺肿块的价值

目的研究彩色多普勒血流显像对乳腺肿块的诊断价值.方法使用彩色超声仪对73例患者77个乳腺肿块进行检查,评价彩色多普勒血流显像特征,并与病理结果对照.结果乳腺恶性肿块的血流较良性明显丰富,恶性肿块的PS平均值为21.2cm/s, RI 平均值为 0.74; 良性肿块的PS平均值为8.6cm/s, RI 平均值为 0.51.恶性肿块PS、RI值均高于良性肿块(P<0.01).结论彩色多普勒血流显像超声对乳腺肿块的鉴别有重要价值.     

多普勒阻力指数在小肝癌定性诊断中的价值

目的　探讨多普勒阻力指数 (RI)在小肝癌定性诊断中的应用价值。方法　本文对 2 97例共 3 0 4个肿块直径 <3 0mm的肝脏实质占位进行了彩色多普勒超声和脉冲多普勒 (PD)频谱分析。其中原发性肝恶性肿瘤 2 18例 ,转移性肝恶性肿瘤 16例 ,肝血管瘤 19例 ,局灶性结节性增生 17例 ,血管平滑肌脂肪瘤 4例 ,炎性假瘤 8例、肝硬化结节 9例 ,肝结核 3例 ,其他良性病变 3例。全部病例均经手术和病理证实。结果　肝脏恶性肿瘤的动脉血流检出率高于良性肿瘤 ,恶性肿瘤动脉血流检出率为 88.2 % ,良性病变者为 5 8.2 % ,二者有显著性差异 (P <0 .0 1)。经多普勒频谱分析 ,肝脏良、恶性病变的阻力指数 (RI)存在显著性差异 (P <0 .0 0 1) ,原发性恶性肝肿瘤的RI值为 0 .77± 0 .12 ,转移性恶性肝肿瘤的RI值为 0 .71± 0 .0 7,良性病变RI平均值在 0 .6以下 ;良、恶性占位的血流阻力不同与病变的病理组织结构有关。结论　如果以彩色多普勒血流显像显示有动脉血流 ,且RI≥ 0 .6作为诊断肝脏恶性肿瘤的标准 ,则敏感性为 96.2 % ,特异性为 88.1% ,准确性为 94.2 %。因此 ,RI有助于小肝癌与良性病变的鉴别 ,有其临床实用价值。一旦肿瘤内部或周边测及动脉血流 ,且RI≥ 0 .6,则恶性肿瘤可能性大 ,如测及静脉血流 ,或测及动脉血     

超声监测失血性休克大鼠肝脏血流动力学的实验研究

目的　研究超声监测大鼠失血性休克过程肝脏血流动力学改变的可行性及可靠性。方法　在大鼠失血性休克前、后及再灌注 2 4h内 ,用 7.5MHz探头对大鼠肝脏进行二维超声 (2DUS)、彩色血流速度图 (CVI) ,脉冲多普勒 (PW )检查 ,测量PV、肝动脉 (HA)血流参数。结果　休克期肝血流动力学改变早于肝生化指标的改变 ,表现为肝内血流分布减少 ;PV流速降低 ;HA的Vmin降低 ,RI升高 (P <0 .0 1)。再灌注期肝内血流分布增多 ;HA的Vmax、Vmin较休克期升高 ,RI下降 ,有非常显著性差异 (P <0 .0 1) ;但RI值与休克前比较仍有显著性差异 (P <0 .0 5 ) ,且PV流速与休克期比较 ,无显著性差异 (P =0 .2 9)。结论　无创性超声检测血流可作为监测失血休克大鼠模型肝脏血流动力学改变的可靠方法。     

乳腺癌血流特征彩色多普勒超声诊断的研究

目的　评价乳腺癌血流特征在彩色多普勒超声诊断中的价值。方法　用CDFI、PDI和 3D DMS检查 171例乳腺肿块 ,定量分析血流灌注量、Vmax、RI、血管数量。结果　乳腺癌相对灌注为 ( 8.2 0 0± 0 .0 0 1) % ,良性肿块 ( 2 .40 0±0 .0 0 2 ) % (P <0 .0 1) ;乳腺癌Vmax为 ( 2 5 .68± 1.11)cm/s,良性肿块 ( 6.10± 0 .2 2 )cm /s (P <0 .0 0 1) ;乳腺癌PI为 1.2 9±0 .3 6,良性肿块 0 .83± 0 .2 2 (P <0 .0 1) ;乳腺癌RI为 0 .7± 0 .0 10 ,良性肿块 0 .49± 0 .0 11(P <0 .0 1) ;血管数量乳腺癌为1.810± 0 .0 2 6,良性肿块 0 .98± 0 .10 0 (P <0 .0 0 1) ,以上各组数字均显示乳腺癌明显高于良性肿瘤。CDFI、PDI和 3D DMS诊断乳腺癌的敏感性为 96.9% ,特异性为 93 .8% ,准确性为 96.8%。结论　超声CDFI、PDI和 3D DMS对早期乳腺癌诊断具有独特价值。     

彩色多普勒超声对子宫动脉栓塞治疗子宫肌瘤的疗效评价

目的　探讨彩色多普超声在子宫动脉栓塞术 (UAE)治疗子宫肌瘤疗效评估中的价值。方法　 1 7例子宫肌瘤患者共 30个肌瘤结节 ,在UAE术前 2d和术后半年内每月定期行超声检查 ,观察子宫及肌瘤的大小、形态、内部回声与血供状况 ,测量子宫动脉、肌瘤周边与内部血管的收缩期峰值流速 (Vs)、舒张期峰值流速(Vd)、阻力指数 (RI)。结果　UAE术前子宫平均体积 435 .1 8cm3,肌瘤平均体积 1 0 2 .47cm3,30个肌瘤结节中2 1个为低回声 ,7个为等回声 ,2个为高回声 ,肌瘤周边回声有晕环 ,周边血流较丰富 ,呈环状、半环状或弓状 ,内部血流较多或稀疏 ,呈点状、短线状 ,或无血流。肌瘤周边RI值高于内部 ,子宫动脉RI低于正常。UAE术后 ,子宫平均体积 2 2 2 .5 1cm3,缩小 48.87% (P <0 .0 1 )。肌瘤平均体积 5 2 .1 0cm3,缩小 49.1 6% (P <0 .0 1 )。术后3个月肌瘤进行性缩小 ,随后趋于稳定。肌瘤内部从“雪片状”高回声逐渐减低 ,演变形成不匀质的稍高回声、等回声或低回声 ,未见液化的囊腔。肌瘤周边晕环消失 ,回声逐渐增高 ,演变形成环样强回声 ,有 3例子宫内可测及条带样强回声 ,走行与子宫动脉分支一致。子宫动脉未全部复通 ,复通的子宫动脉RI进一步降低。肌瘤内部无血流显示 ,肌瘤周边 3个月内无血流显示 ,随后局部出     

彩色多普勒超声探查胸外侧动脉血流动力学参数对乳腺癌诊断价值的研究

目的探讨胸外侧动脉（LTA）血流动力学参数（S/D、RI、PI）在乳腺癌诊断中的价值。方法术前1周对70例乳腺良、恶性肿块患者及30例健康女性进行彩色多普勒超声检查,测量并记录肿块大小、部位、彩色血流分级及LTA血流动力学参数。结果乳腺癌组患侧LTA的S/D、RI、PI明显低于对侧,差异有统计学意义（P〈0.05）。乳腺良性肿块组LTA的S/D、RI、PI两侧比较差异无统计学意义（P〉0.05）。如以LTA的S/DH-C≥1.5为诊断乳腺癌标准,敏感性、特异性分别为83.8%、76.7%;如以LTA的PIH-C≥0.3为诊断乳腺癌标准,敏感性、特异性分别为83.7%、83.3%;如以LTA的RIH-C≥0.06为诊断乳腺癌标准,敏感性、特异性分别为86.4%、90%。相关性分析表明LTA的S/D、RI、PI与肿块大小、肿块内血流分级呈负相关（P〈0.05）,与肿块位置无明显相关性（P〉0.05）。结论应用彩色多普勒超声测定LTA的S/D、PI、RI,可作为诊断乳腺癌的诊断指标之一,LTA的S/D、PI、RI与肿块大小、肿块内血流分级具有相关性。     

超声观察中晚孕期正常胎儿脐动脉和脑、肾动脉血流动力学

目的 探索正常胎儿脐动脉(UA)、大脑中动脉(MCA)和肾动脉(RA)血流参数随孕期变化的规律;建立正常胎儿不同孕期UA、MCA和RA血流参数的参考值范围。方法 应用彩色多普勒血流显像(CDFI)检测220胎21~41孕周正常单胎胎儿UA、MCA和RA血流,测量收缩期峰值流速(PS)、搏动指数(PI)、阻力指数(RI)及收缩期峰值流速与舒张末期流速比值(S/D)。结果 正常胎儿UA、MCA和RA的PS值随着孕周增加而增加;UA和RA的PI、RI和S/D值随着孕周增加而减低;而MCA的PI、RI和S/D值随着孕周增加呈先升高后降低的抛物线状。至足月,PS参考值范围分别为:UA PS(54.96±14.57)cm/s、MCA PS(65.11±11.35)cm/s和RA PS(58.54±10.72)cm/s;UAS/D测值为2.14±0.30;RA RI测值为0.79±0.04;MCA RI测值为0.72±0.05。所有参数的变化在不同孕周组差异均有统计学意义(P均<0.05)。结论 CDFI产前检测胎儿UA、MCA和RA随着孕期变化的血流动力学参数可以同时了解胎儿胎盘循环、颅脑循环及周围循环状态。不同孕期的血流参数的参考值范围可为超声预测胎儿宫内缺氧提供理论依据。     

乳腺癌肿瘤血管的多普勒超声研究

目的 联合应用三种多普勒超声研究乳腺癌肿瘤血管形态学特征及血流动力学的规律。方法选取52例血流较丰富的乳腺癌肿块，采用彩色多普勒（CDFI）、能量多普勒（PDI）及脉冲多普勒（PW）相结合的方法，分析乳腺癌肿块的肿瘤血管形态学特点及肿瘤血管的峰值流速（PS）及阻力指数（RI）的规律。结果52例肿块中发现粗细不均血管、动静脉瘘、扭曲血管、盲端血管的例数分别为27、29、39、18例。盲端血管、扭曲血管的PS均低于血管狭窄处及动静脉瘘处的PS（P＜0．05），前两者之间及后两者之间的PS差异无显著性（P＞0．05）；粗细不均血管、扭曲血管RI值无显著性差异（P＞0．05）。在43例肿块中发现了异常血管分级方式。直径≥2cm的肿瘤的PS高于直径＜2cm的肿块（P＜O．05）。结论联合应用三种多普勒能够较好的显示乳腺癌肿瘤血管的形态学特征;乳腺癌肿块的PS、RI与肿瘤血管的形态及肿块大小密切相关。     

周围型肺肿块周边血流的彩超研究

目的利用彩色多普勒血流显像(CDFI)和脉冲波多普勒技术(PW),对周围型肺肿块周边血流进行研究,以鉴别肿块的良恶性.方法对51例周围型肺肿块(良性18例,恶性33例)周边血流进行CDFI和PW检查.结果良恶性肺肿块周边血流的显示率分别为33%和88%,两者间有显著差异.恶性肿瘤血流程度多为Ⅱ～Ⅲ级,而良性肿瘤多为0～Ⅰ级,两者间有显著差异.恶性肿瘤RI0.47±0.06,PI1.18±0.16,PSV 0.17±0.04m/s,EDV0.07±0.02m/s;良性肿瘤RI0.81±0.12,PI1.68±0.33,PSV 0.29±0.05m/s,EDV0.04±0.01m/s,两者在血流4项指标间有显著性差异.并以RI＜0.59,PSV≤0.25m/s,作为诊断肺恶性肿瘤的标准.结论CDFI和PW能显示肿块周边血流的血管分布和血流频谱,有助于鉴别其良恶性.     

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.