8层螺旋CT冠状动脉成像的价值

目的探讨8层螺旋CT对冠状动脉疾病的诊断价值。方法32例患者进行冠状动脉8层螺旋CT成像（CT angiography，CTA）检查（PTCA术后8例，疑似冠心病者24例），同时对这些患者进行冠状动脉造影（coronary angiography，CAG）检查。以冠状动脉主要节段管腔直径减少〉50％作为诊断冠心病的标准。结果8层螺旋CT对冠状动脉的总体显示率为88．2％，评价冠状动脉狭窄的敏感性64．7％，特异性为86．2％，显示钙化以及非钙化斑块混合存在导致血管狭窄19处，其中高估3处，可以显示冠状动脉内支架位置、形态以及远段血流，但难以准确显示支架内再狭窄和闭塞。结论8层螺旋CT对诊断冠状动脉疾病的意义有限。     

8层螺旋CT冠状动脉成像的价值

目的探讨8层螺旋CT对冠状动脉疾病的诊断价值。方法32例患者进行冠状动脉8层螺旋CT成像(CT an-giography,CTA)检查(PTCA术后8例,疑似冠心病者24例),同时对这些患者进行冠状动脉造影(coronary angiography,CAG)检查。以冠状动脉主要节段管腔直径减少>50%作为诊断冠心病的标准。结果8层螺旋CT对冠状动脉的总体显示率为88.2%,评价冠状动脉狭窄的敏感性64.7%,特异性为86.2%,显示钙化以及非钙化斑块混合存在导致血管狭窄19处,其中高估3处,可以显示冠状动脉内支架位置、形态以及远段血流,但难以准确显示支架内再狭窄和闭塞。结论8层螺旋CT对诊断冠状动脉疾病的意义有限。     

64层螺旋CT评估冠状动脉狭窄的准确性——与传统冠状动脉造影对照研究

目的通过与CAG的比较,研究64层螺旋CT评估冠状动脉狭窄性病变的准确性。方法收集2005年8月-2006年4月于我院行64层螺旋CT冠状动脉成像和传统冠状动脉造影的60例患者的影像资料,评估64层螺旋CT诊断冠状动脉狭窄性病变及对支架及桥血管诊断的准确性。结果64层螺旋CT诊断冠状动脉≥50%、≥70%、<50%狭窄性病变敏感性分别为96.3%、89.3%、67.3%,特异性分别为94.2%、95.6%、86.2%。64层螺旋CT判断支架内≥50%狭窄的敏感性为100%,特异性为80%;判断桥血管及吻合口通畅的敏感性为100%。结论64层螺旋CT诊断冠状动脉中重度狭窄具有较高的准确性。     

64层螺旋CT在评价冠状动脉支架术后支架内再狭窄中的价值

目的探讨64层螺旋CT（64SCT）在评价冠状动脉支架术后支架内再狭窄的能力和可靠性。方法50例冠状动脉支架术后患者（共92枚支架）,同期行64SCT冠状动脉扫描和选择性冠状动脉造影（CAG）。用64SCT的平扫图像行钙化积分测定,以cAG结果为金标准,分析与64SCT诊断支架开通或再狭窄的特异度、敏感度和一致性。结果64SCT对92枚支架显影良好72枚支架中直径≥3．0mm者57枚（79．2％）,64SCT显示支架内狭窄程度〉50％有21枚,CAG证实17枚,CAG和64SCT对其余51枚支架均显示无再狭窄或支架内狭窄程度为0～50％。在64SCT不能进行影像学评价的20枚支架中,支架直径〈3．0mm者8枚（40．0％）。64SCT诊断冠状动脉支架腔内狭窄〉50％的敏感度和特异度分别为94．1％和90．9％,一致率为91．7％,阳性预测值76．2％,阴性预测值98．0％,因其无创性特点而具有临床应用价值。结论64SCT可清晰显示冠状动脉支架的位置、形态、支架远近端血管及支架腔内情况,能较准确地评价冠状动脉支架术后支架内再狭窄的发生,尤其对大直径支架的评估价值较高。     

64 MSCT对冠状动脉支架通畅性评价的准确性与支架材料的关系

目的：探讨64 MSCT对冠状动脉支架通畅性评价的准确性以及与支架材料的关系。方法：采用64排螺旋CT对42例冠状动脉支架植入术后的患者（共89个支架，其中不锈钢支架32个，镍钛合金支架57个）进行MSCT冠状动脉成像，观察支架的通畅性以及与支架材料的关系。并与传统冠状动脉造影（CAG）对照。结果：32个不锈钢支架中，CAG显示正常23个（包括支架内再狭窄<50%），支架内再狭窄（ISR）9个（ISR≥50%）；57个镍钛合金支架中，CAG显示正常47个（包括ISR<50%），狭窄10个（ISR≥50%）。与CAG对照，MSCT正确诊断不锈钢支架狭窄4个（ISR≥50%），正常（包括ISR<50%）18个，不能评价1个。镍钛合金支架狭窄9个（ISR≥50%），正常（包括ISR<50%）45个。MSCT对不锈钢支架和镍钛合金支架狭窄的敏感性、特异性、阳性预测值和阴性预测值分别为44%，81.8%，50%，78%和90%，95.7%，81.8%，97.8%。MSCT对不同材料支架通畅性评价有显著性差异（P＜0.05）。结论：64 MSCT冠脉成像是评价镍钛合金冠脉支架通畅性的一种安全可靠的方法，但对不锈钢支架评价有一定局限性。     

256层螺旋CT在冠状动脉支架植入术后再狭窄的临床价值

目的探讨冠状动脉支架植入术后再狭窄采用256层螺旋CT的临床诊断价值。方法 40例行冠状动脉支架植入术的患者,采用256层螺旋CT评价40例50枚支架有无变形、具体长度、所在位置及形态。结果 256层螺旋CT诊断支架再狭窄的准确性为92.6%,阴性预测值为93.9%,敏感性为88.9%,阳性预测值为94.1%,特异性为96.9%;再狭窄17枚,占34.0%。结论 256层螺旋CT在冠状动脉支架植入术后再狭窄诊断中具有较高应用价值。     

64层螺旋CT冠状动脉成像诊断冠状动脉狭窄价值

目的评价64层螺旋CT冠状动脉成像（CTA）诊断冠状动脉狭窄的准确性与可行性。方法 30例临床拟诊为冠心病的病人行64层螺旋CTA,以选择性冠状动脉DSA造影作为金标准,比较两种检查方法的结果。结果 120段冠状动脉在CTA图像上得到良好显示,达到分析要求。64层螺旋CT诊断冠状动脉狭窄（狭窄程度≥50%）的灵敏度、特异度、阳性预测值和阴性预测值分别为77.8%、85.3%、48.3%和95.6%。结论 64层螺旋CTA显示冠状动脉狭窄具有很高的阴性预测值,可作为一种无创检查技术对冠状动脉狭窄进行筛查。     

64螺旋CT冠脉成像在冠心病诊断及PCI术后评估中应用研究

目的:探讨64螺旋CT冠脉成像在诊断冠心病及经皮冠状动脉介入治疗(PCI)后评估中的应用价值。方法:回顾性分析2016年5月-2018年5月我院收治的60例疑似冠心病患者病例资料,所有患者均行CT冠脉成像(CTA)检查,并将冠状动脉造影作为"金标准",分析CTA诊断结果。结果:在60例疑似冠心病患者中,冠状动脉造影检出阳性32例,阴性28例,CTA诊断敏感性、特异度、准确度分别为90.63%、82.14%、85.00%;32例患者行PCI术治疗共植入冠状动脉支架44枚,其中术后冠脉造影显示非狭窄35枚,再狭窄9枚,CAT显示非狭窄35枚,再狭窄7枚,有2枚因图像模糊无法进行评价,得出CTA诊断冠状支架再狭窄敏感性、特异度、准确度分别为77.78%、100%、95.45%。结论:64螺旋CT冠脉成像技术具有便捷、无创等优势,其在冠心病诊断中具有较高应用价值且可较好的判断PCI术后支架狭窄情况。     

多层CT评价冠状动脉支架段血管狭窄的临床研究

[目的]评价多层CT(MSCT)诊断冠状动脉支架段血管狭窄的价值.[方法]对62例成功经皮冠状动脉介入治疗术后患者,于随访期同时行MSCT冠状动脉成像和冠状动脉造影(CAG)检查.对其中的33例患者进行了MSCT和CAG的对照研究.[结果]80枚支架的MSCT重建图像中,57枚支架CT图像可评价(占71.25%).不能评价的主要原因是移动伪影(13/23,57%)和严重钙化(8/23,35%).CAG显示33例患者的42个支架段血管,重度狭窄5例,中度狭窄3例.MSCT显示重度狭窄为11例,中度狭窄为14例.MSCT诊断重度支架内狭窄及中重度支架内狭窄的敏感度100%、100%;特异度84%、50%;准确度86%、60%;阳性预测值45%、32%;阴性预测值100%、100%.42个支架段冠状动脉直径的测量结果,MSCT和CAG比较差异有显著性(1.33±0.74 mm vs 2.28±1.05 mm,P＜0.05).[结论]①MSCT冠状动脉成像有助于排除支架内狭窄.②如果图像质量满意,MSCT诊断支架内重度狭窄有较高的准确度.③影响MSCT诊断支架段冠状动脉狭窄的主要因素是运动伪影和冠状动脉弥漫性钙化.     

冠状动脉CTA成像对冠心病临床诊断价值的初步研究——附108例冠状动脉CT成像与冠状动脉造影的对照分析

目的：评价多层螺旋CT冠状动脉成像对冠状动脉病变的诊断价值。材料与方法：对108例冠心病行多层螺旋CT（MSCT）增强扫描及图像后处理,并与常规冠状动脉造影（CAG）做对照分析。结果：常规冠脉造影（CAG）诊断冠脉病变138支,包括轻度狭窄50支,中度狭窄52支,重度狭窄36支,冠脉CTA成像检出冠脉病变152支,轻度狭窄56支,中度狭窄59支,重度狭窄37支。结论：多层螺旋CT对冠状动脉粥样硬化狭窄程度的判断。几乎可以代替有严重并发症的冠状动脉造影,且基本可以准确显示各种粥样斑块的病理性质,并对斑块的稳定性做出判断,评估急性冠脉事件的发生,具有较高的临床应用价值。是安全、准确、可靠的冠心病诊断方法,为冠脉事件的预防治疗和冠脉支架植入术前提供了诸多信息。     

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.