多层螺旋CT冠状动脉造影图像质量的影响因素分析

目的探讨心率对多层螺旋CT冠状动脉造影图像质量的影响和最佳重建相位窗的选择。方法回顾性分析67例患者16层螺旋CT心电门控条件下冠状动脉造影图像。按心率分成≤60次/min、61～70次/min、71～80次/min和≥81次/min分成第1～4组,将冠状动脉图像按伪影多少及血管连续性分为1～3分,评价心率与图像质量的关系,并优选出各组显示冠状动脉的最佳相位窗。结果对每位患者4条冠状动脉(右冠状动脉、左冠状动脉主干、左前降支、左回旋及图像质量进行研究。心率≤60次/min,可用于分析的图像占86.7%;心率61～70次/min,可用于分析的图像占62.5%;心率71～80次/min,可用于分析的图像占40%;心率≥81次/min,可用于分析的图像占12.5%。第1、2组与第3、4组间冠脉总的检查成功率有统计学差异(P<0.05)。第1组所有冠状动脉节段以75%相位窗为最佳;第2组冠状动脉节段以75%为最佳相位窗占89.5%,第3组左右冠状动脉以45%和75%为最佳相位窗分别占45%和55%,第4组全部冠状动脉节段以45%为最佳相位窗。结论心率对多层螺旋CT冠状动脉造影图像质量有重要影响;心率70次/min以下冠状动脉最佳相位窗通常为75%,心率71次/min以上时,应该以30%～90%多相位重建。     

多层螺旋CT冠状动脉成像的初步临床应用

目的:初步探讨MSCT冠状动脉成像的临床应用价值。方法:45例临床诊断或可疑冠心病的患者做MSCT冠状动脉成像检查(回顾性心电门控、0.5s螺旋扫描、心脏分段重建算法和静脉注射对比剂)。在9个心电相位窗上对冠状动脉进行图像重建并分析影像学表现。结果:45例中,左前降支、左回旋支和右冠状动脉重建图像质量最佳的相位窗多数为70%,分别占84.4%,77.8%和66.7%。左冠状动脉主干、左前降支、左回旋支和右冠状动脉显示较好且能满足影像学评价分别占93.3%,80%,60%和42.2%。在心率<60次/分的16例中,左前降支、左回旋支和右冠状动脉显示较好且能满足影像学评价分别占93.8%,75%和62.5%。在心率为60~70次/分的21例中,左前降支、左回旋支和右冠状动脉图像质量较好且能满足影像学评价分别占85.7%,66.7%和42.9%。在心率>70次/分的8例中,左前降支、左回旋支和右冠状动脉图像质量较好且能满足影像学评价分别占37.5%,12.5%和0。在冠状动脉正常或狭窄程度<50%的12例中,二维曲面重建图像显示左前降支、左回旋支和右冠状动脉的长度分别为108±15mm,81±26mm和126±16mm。结论:MSCT在多数情况下能较好地显示冠状动脉,可以作为冠状动脉病变的筛选方法。     

64层螺旋CT冠状动脉成像技术的体模实验

目的 采用心脏动态冠脉体模,对影响64层螺旋CT冠状动脉图像质量的因素进行分析.方法 本研究利用心脏动态冠脉体模,在心律整齐的条件下,改变不同的心率;在心律变化的条件下,改变心率波动的范围,采用不同重组算法、图像重组相位窗,评价64层螺旋CT冠状动脉图像质量.结果 图像质量最佳心率为≤70次/分,心率波动≤10次/分,图像质量在R-R间期的75%左右相位(舒张中期)最好.当心率较快时(≥80次/分),在R-R间期45%左右相位能够获得相对好的图像质量.心率较慢而波动小,冠状动脉成像采用segment(单扇区)重组算法,图像质量比较好;而心率快、波动比较大时,冠状动脉成像采用plus(四扇区)重组算法,图像质量比较好.结论 心率、重组算法和图像重组相位窗是影响多层螺旋CT冠脉成像的主要参数,在应用中应适当运用以上的参数,才能获得优质的图像.     

影响64排多层螺旋CT冠状动脉血管成像质量的相关因素

目的 探讨影响64排多层螺旋CT( multislice detector CT,MDCT)冠状动脉(冠脉)血管成像质量的因素,以提高诊断准确性.方法 收集55例临床怀疑冠心病而行MDCT冠脉血管成像检查的影像资料,评价MDCT冠脉血管成像对冠脉的显示能力,分析影响图像质量因素及管腔狭窄程度.结果 55例均利用多种后处理技术进行重建,图像质量1级48例(87.3％),2级6例(10.9％),3级1例(1.8％).图像质量1级者79.2％心率＜60/min,图像质量3级的1例心律不齐且心率变化＞ 10/min.40例在75％的相位窗重建中冠脉显示最佳.结论 MDCT冠脉血管成像可作为冠心病的筛选手段及冠脉术后复查的首选方法,在75％的相位窗重建中冠脉显示最佳,但心率和心律等对其图像质量有重要影响.     

心率对64层螺旋CT冠状动脉成像质量的影响

目的评价心率对64层螺旋CT冠状动脉成像质量的影响。方法对260例行64层CT冠状动脉CTA检查的连续病例进行分析评价,心率为46~113次/min,平均(72.10±12.54)次/min。应用1~4级评分标准进行图像质量评分,统计检查成功率(评分2以上)和图像优良率(评分3以上),比较心率为<60次/min、60~69次/min、70~79次/min、80~89次/min和≥90次/min时冠脉图像质量与心率的关系。同时分析不同心率下图像重建时相选择。统计分析心率与成像质量的关系以及不同心率时,冠脉检查成功率、显示优良率和重建心动周期时相的差异。结果260名受检者,冠状动脉显示成功率为99.26%(2581/2600),显示优良率为88.69%(2306/2600)。心率与成像质量呈负相关(r=-0.92)。心率<70次/min与心率≥70次/min者在显示优良率方面存在显著性差异(χ2=44.68,P<0.01)。心率<80次/min,重建时相以舒张中期(50%~75%)为主,心率≥80次/min,重建时相以收缩末期(25%~45%)为主(χ2=98.88,P=0.000)。结论心率与冠状动脉成像质量明显相关,64层螺旋CT在高心率下可以获得达诊断标准冠脉图像,心率在70次/min以下图像质量较高。     

心电门控多层螺旋CT冠脉显像与常规冠脉造影对比研究

目的:回顾性分析心电门控多层螺旋CT(MSCT)经静脉注射对比剂冠状动脉成像的可行性,探讨MSCT在冠状动脉疾病诊断的可行性及对冠脉狭窄的显示能力。方法:30例窦性心律患者经MSCT检查1~3天后行定量冠脉造影。以3.5ml/s速率经静脉注入对比剂,延迟15s,用GE公司MSCT机进行扫描,要求患者1次屏气30s,采用回顾性心电门控显像窗进行显像重建。分析所有直径≥2mm冠脉及分支并识别狭窄(≥50%)及闭塞病变。其结果与定量冠脉造影进行对比。结果:在253支冠脉(左主干、左前降支、左回旋支和右冠脉,包括≥2mm的侧支)中218支(86.2%)可评价;11例(36.7%)患者所有冠脉均可评价。检测明显狭窄(≥50%)的敏感性是82.6%、特异性是97.9%;阳性预测值(PPV)是82.6%、阴性预测值(NPV)是97.9%;高度狭窄(≥75%)的敏感性、特异性分别是83.3%、98.1%。总的敏感性(包括MSCT不可评价的血管)是68.4%。对于右冠脉近段、左主干、前降支的MSCT直径测量与定量冠脉造影相比相关性较好。结论:采用回顾性心电门控多层螺旋CT冠脉成像在显像质量较好的情况下,具有较高的准确性。由于目前MSCT不能有效消除冠脉运动的伪影影响,限制了该技术的临床应用,但仍然是一项有前途的冠状动脉疾病诊断方法。     

多层螺旋CT前瞻性心电门控技术在冠状动脉成像中的应用研究

目的:评估多层螺旋CT(MSCT)前瞻性心电门控冠脉扫描模式对冠状动脉狭窄程度显示的价值及图像质量,并评估患者接受的辐射剂量。材料与方法:将104例拟诊冠心病患者分两组分别行前瞻性和回顾性心电门控冠状动脉CTA扫描,采用容积再现技术重建(VR)、最大密度投影(MIP)、多层面重组(MPR)和二维曲面重建(CPR)等多种重组技术显示各节段冠状动脉,评价其图像质量,并分别计算有效辐射剂量。结果:两组患者(除回顾组平均心率较前瞻组略高)临床资料匹配性、图像质量的评价一致性良好,差异无统计学意义。前瞻组符合诊断要求的冠状动脉节段为95.6%(568/594),与回顾组冠状动脉节段的96.5%(614/636)比较,差异无统计学意义。前瞻组50例患者中594个冠状动脉节段中,MSCT诊断冠脉狭窄程度≥50%的节段为69个。回顾组54例患者中636个冠状动脉节段中,MSCT诊断冠脉狭窄程度≥50%的节段为61个。前瞻组平均辐射剂量为(3.62±0.37)mSv,回顾组平均辐射剂量为(15.18±0.96)mSv,两组间差异有统计学意义(P<0.001),两组辐射剂量有明显差异。结论:256层螺旋CT冠状动脉前瞻性心电门控技术评估冠状动脉成像图像质量及管腔狭窄的效果与回顾性心电门控扫描技术相似,但前者的有效辐射剂量明显减少。     

心率及心律对320排容积CT冠状动脉血管成像及相关辐射剂量的影响

目的探讨320排容积CT(DVCT)冠状动脉血管成像心率(律)对图像质量、诊断准确性及辐射剂量的影响。方法回顾性分析济南军区总医院2009年11月至2010年7月行DVCT冠状动脉血管成像患者94例,男65例,女29例,年龄39～91岁,平均(65.6±10.3)岁。以图像质量1级(无运动伪影,优)至4级(严重伪影,差),按照美国心脏协会推荐的15分段法对冠状动脉图像质量进行评价。心率以扫描各心跳平均值表示,心律变化程度以扫描各心跳标准差(SD)表示。分析心率及心律变化对图像质量、辐射剂量的影响。对其中35例冠状动脉血管成像CT检查发现异常患者行冠状动脉导管造影(ICA),分析DVCT冠状动脉血管成像诊断管腔明显狭窄(狭窄率≥50%)的敏感度、特异度、阳性预测值(PPV)、阴性预测值(NPV)。对双变量非正态分布资料采用Spearman相关分析或直线回归分析;利用多元回归分析心率与心律变化的相互作用。结果 (1)图像质量随着心率增高而降低(P<0.001),主要集中于优-良的转变,心律变化对图像质量无明显影响(P=0.16),通过心电编辑,优、良图像质量占96.4%,可诊断节段达99.7%;(2)平均辐射剂量...     

多层螺旋CT冠脉成像与选择性冠脉造影初步探讨

目的评价多层螺旋CT(MSCT)诊断冠状动脉狭窄的可行性和准确性.方法35例临床拟诊冠心病患者行冠状动脉MSCT成像,同时接受选择性冠状动脉造影.分析MSCT图像质量,并与选择性冠状动脉造影相比较.结果以冠状动脉造影结果作为金标准,MSCT诊断狭窄≥50%的敏感度、特异度、阳性预测值、阴性预测值分别为79.4%、95.7%、83.1%、94.6%.结论MSCT能较准确诊断冠状动脉50%以上的狭窄,是无创性诊断冠状动脉狭窄的重要工具.     

双源CT自适应心脏步进扫描技术在高心率患者冠状动脉成像中的应用

目的 探讨双源CT自适应心脏步进扫描技术在高心率患者冠状动脉成像中的应用价值.方法 连续采集58例接受DSCTA检查(心率≥70次/分,均未进行人为干预)的患者资料.数据采集期相为45%R-R间期,重建期相为45%±8%.采用Kruskal Wallis H检验分析平均心率、心率变化与图像质量间的关系;ROC曲线分析检验平均心率、心率变化对移动伪影产生的影响.14例患者在DSCTA后接受冠状动脉造影(CAG)检查.采用CTDI和DLP计算有效辐射剂量.结果 58例纳入患者中,可供评价的血管为948段,图像质量评价为1～3级者占95.68%(907/948).对于不同的心率变化,不同级别的LAD、LCX的显示节段数比较差异有统计学意义(P<0.05).ROC曲线分析表明平均心率对冠状动脉移动伪影的产生有统计学意义(AUC:0.75,95%CI:0.55～0.96,P<0.05).DSCTA诊断狭窄程度<50%及≥50%血管的敏感度分别为80.00%(8/10)和90.48%(38/42);诊断血管狭窄的特异度为95.51%(170/178),阴性预测值为96.59%(170/176).有效辐射剂量为(6.46±0.12)mSy.结论 双源CT自适应心脏步进扫描技术对于心率≥70次/分的患者无需刻意降低心率,心率变化平稳患者均能得到良好的图像质量,诊断效能较高,可明显降低辐射剂量.     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.     

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.     

Interprofessional approaches to creating safe,high quality health care

Three supplementary perspectives are presented arguing that interprofessional collaboration is both necessary and desirable. Nonetheless, there are often too many serious intra-professional barriers and obstacles to interprofessional collaboration to make it successful. Some of these barriers, it is argued and illustrated, are found in the multiple ways in which professional identity is tacitly acquired and embodied in the practitioners' habitual, everyday practice. The paper then explores ways in which reflection, especially Second order reflection, can help to elucidate and overcome these obstacles, as well as increasing professional adaptability and competence.     

Systematic Reviews Published in the January 2011 Issue of The Cochrane Library

ABSTRACT

The Cochrane Library of Systematic Reviews is published quarterly as a DVD and monthly online. The January 2011 issue (first quarterly DVD for 2011) contains 4515 complete reviews, 1985 protocols for reviews in production, and 13,521 one-page summaries of systematic reviews published in the general medical literature. In addition, there are citations of 641,000 randomized controlled trials, and 14,018 cited papers in the Cochrane methodology register. The health technology assessment database contains over 9300 citations. One hundred and seven new reviews have been published in the last 3 months, of which five have potential relevance for practitioners in pain and palliative medicine.     

Modified micro-superior percutaneously-assisted total hip: early experiences & case reports

Because of the extensile nature and familiarity of the standard posterior-lateral approach to the hip, a family of "micro-posterior" approaches has been developed. This family includes the Percutaneously-Assisted Total Hip (PATH) approach, the Supercapsular (SuperCap) approach and a newer hybrid approach, the Supercapsular Percutaneously-Assisted Total Hip (SuperPATH) approach. Such approaches should ideally provide a continuum for the surgeon: from a "micro" (external rotator sparing) posterior approach, to a "mini" (external rotator sacrificing) posterior approach, to a standard posterior approach. This could keep a surgeon within his comfort zone during the learning curve of the procedure, while leaving options for complicated reconstructions for the more practiced micro-posterior surgeons. This paper details one author's experiences utilizing this combined approach, as well as permutations of this entire micro-posterior family of approaches as applied to more complex hip reconstructions.     

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.     

Structure and function of "metalloantibiotics"

Although most antibiotics do not need metal ions for their biological activities, there are a number of antibiotics that require metal ions to function properly, such as bleomycin (BLM), streptonigrin (SN), and bacitracin. The coordinated metal ions in these antibiotics play an important role in maintaining proper structure and/or function of these antibiotics. Removal of the metal ions from these antibiotics can cause changes in structure and/or function of these antibiotics. Similar to the case of "metalloproteins," these antibiotics are dubbed "metalloantibiotics" which are the title subjects of this review. Metalloantibiotics can interact with several different kinds of biomolecules, including DNA, RNA, proteins, receptors, and lipids, rendering their unique and specific bioactivities. In addition to the microbial-originated metalloantibiotics, many metalloantibiotic derivatives and metal complexes of synthetic ligands also show antibacterial, antiviral, and anti-neoplastic activities which are also briefly discussed to provide a broad sense of the term "metalloantibiotics."