成人中耳、内耳解剖结构螺旋CT三维成像

目的：建立成人中耳，内耳解剖结构三维立体图像模型。方法：采用螺旋CT薄层扫描（层厚1mm或2mm)，小视野（FOV=5cm)，密集重建技术（间隔0.2mm或0.5mm)，对90例成人中耳，内耳进行三维成像。包括多平面重组（MPR），最大密度投影（MIP），表面成像（SSD）和仿真内窥镜成像（CTVE）。结果：中耳彭室，听骨链，内耳及内耳道分别三维成像，全面显示了各结构相互关系。表面及内部形态。结论：螺旋CT三维成像能够全面准确观测成人中耳，内耳立体结构。     

螺旋CT及三维重建技术在中央型肺癌诊断中的应用价值

目的 探讨螺旋CT及三维重建技术对中央型肺癌诊断的临床应用价值。方法 中央型肺癌（n=23)患者行螺旋CT薄层扫描（层厚2mm-3mm)且行三维重建,三维重建方法包括表面遮盖成像（SSD）、最小密度投影（MinIP)及多平面重建（MPR）。结果 螺旋CT薄层图象及MPR重建均可准确显示中央型肺癌病灶发生部位,气管支气管阻塞气管树SSD及MinIP成像可整体直观显示其阻塞和狭窄范围及程度,SSD及MinIP图像较粗糙,显示病灶解剖细节差,对显示早期小病灶及小支气管改变有一定限制。结论 螺旋CT薄层横断面及MPR图像是诊断中央型肺癌准确有效方法,SSD及MinIP图像较直观,可弥补其横断面图像的不足,但不能显示病灶的解剖细节。     

64层螺旋CT诊断先天性血管环

目的 探讨64层螺旋CT对先天性血管环的诊断价值.方法 回顾性分析32例先天性血管环患者的CT资料,并进行多平面重组(MPR)、最大密度投影(MIP)、最小密度投影(MinIP)、容积再现(VR)及图像融合技术,评价图像质量能否满足诊断要求以及图像重组的可行性.结果 32例患者的扫描图像均能够进行三维重组,重组图像能够很好地显示心血管解剖.MPR、VR重建图像直观显示血管环的组成及空间关系,MinIP及气管VR重建图像清晰显示气道形态及发育状况,图像融合技术可直观显示血管环与气管、食管的空间关系.结论 64层螺旋CT轴位扫描结合多种三维重建后处理技术可直观、清晰显示血管环的组成及与气管、食管间的毗邻关系,是检查血管环的有效手段.     

螺旋CT三维重建方法在颞骨影像学的对比研究

目的:探讨成人颞骨螺旋CT三维重建技术。方法:对正常30耳,慢性化脓性中耳炎41耳行螺旋CT检查,把扫描所得的容积数据进行三维重建,包括最大密度投影法(MIP)、最小密度投影法(MinIP)、仿真内窥镜法(CTVE)和容积再现法(VR)。结果:MIP、MinIP、CTVE和VR可以从不同的方面对颞骨内结构进行三维显示。结论:对于颞骨内结构的显示,VR是目前较好的三维重建方法。     

多层螺旋CT三维重建在脾动脉瘤诊断中的价值

目的　探讨多层螺旋CT三维重建在脾动脉瘤诊断中的价值。方法　多层螺旋CT腹部检查发现 5例脾动脉瘤 ,均经DSA证实。其中 4例为腹部常规扫描模式所发现 ,1例行血管成像检查 ,扫描参数与常规扫描模式参数相同。血管三维成像方法为SSD ,MIP及容积显示技术 (VRT)。结果　应用多层螺旋CT常规扫描模式进行血管结构三维重建即可明确显示脾动脉瘤 ,VRT成像较SSD、MIP能较好地显示脾动脉瘤的特征。结论　多层螺旋CT三维重建在诊断脾动脉瘤方面具有明显优势 ,VR技术成像优于SSD及MIP ,可取代常规血管造影检查     

多排螺旋CT在肋骨骨折诊断中的价值探讨

目的:探讨多排螺旋CT在肋骨骨折扫描检查中的应用价值。方法:利用GE的Lightspeed8排螺旋CT对56例胸部外伤患者进行多排螺旋CT扫描检查,对原始数据进行薄层图像重建并传至工作站,进行容积再现(VR)、多平面重组(MPR)、最大密度投影(MIP)、表面遮掩(SSD)图像重建,观察和分析肋骨骨折情况、周围其他解剖结构病变。结果:56例患者中除1例患者无肋骨骨折外其余55例患者均有单发或多发肋骨骨折,共计检查出肋骨数量为105根,CT原始扫描数据发现肋骨骨折103根,CT层厚为2.5mm薄层重建图像数据发现肋骨骨折为105根,重建三维图像VR、MIP、MPR、SSD发现肋骨骨折为102根,结合上述图像能清晰显示肋骨骨折情况、骨折数量、是否错位,除发现X线片肋骨骨折不明显骨折情况,同时还发现周围其他解剖结构外伤情况。结论:利用多排螺旋CT多种图像重建,其对肋骨骨折诊断准确性要优于常规X线检查,可弥补X线检查中不足,为临床诊治肋骨骨折提供重要价值。     

螺旋CT扫描三维骨重建在颌面部病变中的临床应用

目的:探讨螺旋CT三维骨重建在颌面部病变中的成像技术及临床应用价值。材料与方法:对42例颌面部行螺旋CT扫描后进行三维骨重建,5例非螺旋CT扫描作为对照。结果:颌面部螺旋CT扫描以层厚2mm~5mm为宜,螺距1为佳,后重建以1mm间隔重组,强调成像技术是影响图像质量的主要因素。三维表面遮盖法重建技术(SSD)能清楚地显示骨折部位、分型、移位情况以及肿瘤整体形态、内部结构,图像立体感强。结论:螺旋CT扫描三维骨重建有利于颌面部骨折、肿瘤的诊断,有利于治疗和手术方案的制订。     

螺旋CT三维成像在颌面骨病变中的应用价值

目的探讨螺旋CT三维成像在颌面骨病变中的应用价值。方法对48例颌面骨病变患者行三维CT检查,重建间隔1.0mm,螺距比1.5,数据传入工作站,用表面遮盖显示法(surfaceshadeddisplay,SSD)及容积成像(volumetricredering,VR)进行处理;并将三维CT成像与手术病理结果进行对比分析。结果全部颌面骨病变三维CT均能立体显示,显示骨折的类型、位置、走行等空间信息三维CT优于二维CT;对骨质破坏显示较直观,但不能显示软组织改变。结论三维CT成像能清楚显示病变的空间解剖关系,而三维CT及二维CT在颌面骨病变中的显示和诊断中各有其特点,两者相结合能提高病变诊断的准确性。     

国人内耳膜迷路高场MR成像

目的探讨内耳膜迷路MR成像技术,建立内耳各主要结构的MR测量正常值。方法选择35例无耳部疾病患者(男25例,女10例),使用Siemens1.5T超导MR机(MAGNETONVISION),头颅线圈,3DFT-CISS序列(Three-DimensionalFourierTransfor-mation-ConstructiveInterferenceinSteadState),轴位或冠状位扫描,用多平面重建(MPR)及最大强度投影(MIP)技术对兴趣区重建。观察内听道及内耳膜迷路结构。结果全部受试者均能满意显示两侧内听道及内耳膜迷路的解剖结构,原始图像及MPR能清晰显示第Ⅶ、Ⅷ对颅神经;MIP能三维显示膜迷路,但对颅神经的显示不及MPR。半规管直径约1.00～1.33mm,前庭垂直径约3.07～3.33mm,蜗底直径约6.41～7.02mm,耳蜗高度约4.19～4.64mm。结论3DFT-CISS序列为研究内耳的解剖及病变提供了一种很有价值诊断工具。     

64层螺旋CT后处理技术在外中内耳畸形诊断中的价值

目的：探讨多层螺旋CT容积再现技术（VRT）、曲面重建及多平面重建（MPR）等后处理技术在显示外中内耳畸形中的价值。方法：应用我院64层螺旋CT扫描机,对16例外中耳畸形及18例内耳畸形的患者行容积扫描并行听小骨及内耳骨迷路的MPR及VR重建,畸形的面神经管行曲面重建。结果：16例外中耳畸形为外耳道先天闭锁或狭窄,鼓室及乳突窦不同程度变小,听小骨发育畸形,面神经管畸形。18例内耳畸形中有12例为前庭导水管扩大;6例耳蜗、前庭或半规管不同程度畸形,其中3例同时伴有前庭导水管扩大。结论：VR可清晰显示听小骨及内耳耳蜗、前庭、半规管的形态及畸形程度;MPR可对外耳道骨性闭锁板的厚度、鼓室及乳突窦的狭窄程度,听小骨与鼓室壁的关系,有无前庭导水管扩大及扩大的形态给出较明确的回答;面神经管曲面重建对面神经管的畸形情况显示清晰。多种后处理技术的综合应用将使外中内耳畸形的诊断万无一失。     

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.