影响CR摄影质量常见问题的探讨

目的分析计算机X线摄影（CR）中存在的质量问题,以提高CR的图像质量。方法回顾分析我院2010年3月至9月产生的有问题CR图像（含照片）351幅。结果 351幅有问题图像中,属于人为与外在因素造成的现象有180幅（51.28%）;摄影条件选择不当致图像不佳66幅（18.80%）;与成像板（IP）相关因素致图像伪影64幅（18.24%）;IP在读取或数据传输过程中出现的伪影15幅（4.27%）;打印机故障所致14幅（3.99%）;后处理不当致图像假象或质量不佳12幅（3.42%）。结论规范操作规程,注意对CR系统,IP以及打印机的日常维护和保养,是保证CR图像质量和提高诊断水平的重要环节。     

计算机X线摄影伪影产生原因及消除方法

X线伪影影响影像诊断的精确度。绝大多数的传统放射学伪影我们熟悉,但CR系统的伪影与传统放射学的伪影不尽相同。CR系统伪影分别与影像板,影像板读取装置,图像后处理软件,激光打印机和操作者失误有关。了解CR产生伪影的原因有助于识别并及时消除伪影,提高影像质量。     

中心线在DR摄影质量中的作用体会

目的：探讨X线摄影中中心线对数字摄影DR摄影质量的重要性。方法总结我院在运用X线数字摄影DR近两年的工作经验,分析在X线摄影中影响影像质量的原因,中心线未对准受检部位的入射点占很大比例,达到58%。结果汇总查找出X线数字摄影DR操作中影响影像质量的因素,调整好中心线,重新达到诊断要求。结论重新调整好中心线对准受检部位的入射点,排除影响摄影质量的其他因素后,图片质量获得良好效果,达到了影像诊断要求。     

数字化X线摄影在胸部摄影中的应用

目的 探讨直接数字化X线摄影(DR)在胸部肋骨摄影中的应用价值.方法 对50例DR胸部正位影像采用图像后处理方法中多级图像对比增益法,影像切割与局部放大等功能进行后处理,同时用数字随机法对其中20例行普通X线摄影.由放射科经验丰富的医技师对胸部肋骨影像进行分析,评价其对肋骨骨折、肋骨及胸部其它组织的显示.结果 50例DR胸部影像中,诊断肋骨骨折28例,肋骨及胸部其它软组织显示满意度为95%.对照20例普通X线胸部发现肋骨骨折6例,漏诊3例,20例肋骨及胸部其它组织显示满意度为62%.结论 DR影像比普通X线影像能更好显示胸部肋骨,提高肋骨骨折的检出率.     

婴幼儿胸部CR摄影的质量控制

目的探索婴幼儿胸部CR摄影的影响因素,提高婴幼儿胸部CR摄影影像质量。方法随机抽取2009年1月至2012年2月500例0～2岁婴幼儿胸部CR摄影图像,进行质量评析。其中男性280例,女性220例。由一位医学影像学副主任医师及两位主管技师对所抽取图像,根据中华医学会影像技术学会在欧共体影像综合评价标准的基础上,制定的《常规X线影像质量标准(草案)》的标准进行评定。重点观察:图像的体位,肺组织的扩张度,对比度,清晰度,是否有异物残留及IP板使用的合理性等。结果甲级片450例,占90%;乙级片45例,占9%;其中体位不正10例,占2%,中心线位置不当3例,占0.6%,肺组织扩张不佳,对比度差23例,占4.6%,摄影条件不当5例,占1%,异物伪影2例,占0.4%,IP板使用不当2例,占0.4%;废片5例,占1%,多表现为体位不正,运动模糊,肺组织扩张不佳,呼气相,对比度差等,为保证影像质量,均已选择重拍。结论婴幼儿胸部CR摄影质量的影响因素很多,摄影条件,体位设置,曝光时机,中心线的投射位置以及IP板处理因素和图像后处理,激光照片的打印等诸方面因素均能影响婴幼儿胸部CR摄影质量,只有使各个环节都良好匹配,才能保证影像质量的优良。     

磁共振影像技术进展

2004年11月下旬在美国芝加哥举行的北美放射学会(RSNA)中,MRI临床应用(即解决临床应用中的难点与盲点以发挥临床、科研与教学等方面的最佳作用)新进展是所有放射影像领域(如多层螺旋CT、数字化平板DSA、X线数字摄影等)中最引人注目、最具前沿发展的新亮点,及解决MRI在临床与科研应用中困扰多年的难题,如伪影、心脏应用、分子影像发展和MRI治疗等.     

DR双能量减影技术在胸外伤诊断中的价值

目的 探讨数字X线摄影(DR)双能量减影技术在胸外伤诊断中的价值.方法 回顾性分析164例胸外伤患者的常规条件DR摄影图像和通过双能量减影技术进行处理的图像,比较两组图像的差别,由影像专家对不同方法产生的图像质量进行评价.结果 164例胸外伤的病例,常规DR胸片不能明确诊断,应用DR双能量减影技术得到单纯肋骨影像,DR常规胸片疑似肋骨骨折的病例均做出了肯定的诊断.结论 运用双能量减影技术能使肋骨的图像质量明显提高,可以增强肋骨和骨骼轮廓及细微的骨结构,提高肋骨边缘的锐利度,从而达到对肋骨的不完全骨折及隐匿性骨折鉴别的目的.     

CT图像伪影及处理方法

介绍了CT常见图像伪影、产生原因以及相应的处理方法,旨在帮助影像医技人员及工程技术人员对CT伪影有进一步的认识。     

数字X线检查在静脉尿路造影中的临床应用

目的探讨数字化X线摄影技术(DR)静脉肾盂造影(IVP)中的临床应用价值。方法采用GE数字X线机对125例静脉尿路造成影的病例进行分析,常规腹部准备及碘过敏试验,上臂静脉注射泛影葡胺40ml,头低足高10°～15°,动态采集数据,视检查影像可进行调整体位及延时检查。结果 125例静脉尿路造影经数字动态采集图像后,影像清晰,除2例肾功能不全者显影效果较差外,其余均取得比较满意的效果。其中,泌尿系结石101例。先天畸形3例,腹部占位2例,肾占位2例。膀胱病变38例(含结石、前列腺肥大,占位)。结论数字X线(DR)检查由于其影像清晰,动态实时成像,多轴位的观察,检查方法简单,无痛苦,加上优越的图像后处理功能,可使泌尿系疾病的诊断得到进一步的提高。应在临床中广泛推广应用。     

新生儿床边胸部两种X线摄影结果比较分析

目的对新生儿床边胸部计算机X线摄影(CR)和数字X线摄影(DR)各200例资料进行回顾性对比分析,探讨DR和CR的优势和局限性。方法对我院2009年3月至2012年1月拍摄的新生儿床边胸片,分别随机抽取200张DR胸片和200张CR胸片,由主管技师、副主任医师和主任医师各1位按感蓝X线影像评片标准评判分析,并综合比较,分析指标包括胸片影像质量、个人辐射剂量及摄影时间等。结果 DR组图像的合格率、优质片率明显高于CR组,且辐射剂量减少31.2%,可快速获得图像。结论新生儿床边胸部DR摄影具有较多优势。     

床边数字化X线摄影影像质量的影响因素分析

目的通过对床边DR的影像质量的影响因素分析,总结DR床旁摄影的经验与教训,提出改进方法。方法对1265份数字化x线影像资料（1265张影像片）进行回顾性分析,并按部位、阳性率及图像质量进行统计和分析,探讨影响成像质量因素。结果1265份影像片中,甲级片1032张,甲级片率为81．6％;乙级片181张,乙级片率为14．3％;丙级片52张,丙级片率为4．1％,没有废片。对233张非甲级片进行影像质量原因统计、分析及分类。其中由设备性能问题所致为39张,占16．7％;图像噪声：15张,占6．4％;摄片技术：101张,占43．3％;图像后处理：31张,13．3％;激光相机与打印：10张,占4．3％;人为因素的影响37张,占15．9％。结论影响DR照片质量因素很多,技术人员的操作技能和水平是其主要因素。     

64层螺旋CT冠状动脉成像图像质量及伪影分析

目的探讨64层螺旋CT无创性冠状动脉成像图像质量的影响因素及常见伪影的分类、成因及应对方法。方法对150例患者行64层螺旋CT冠状动脉成像的图像进行分析，评价图像质量并对伪影进行分类。结果64层螺旋CT冠状动脉成像图像质量与患者心率、呼吸运动及冠状动脉钙化积分等因素呈负相关，常见伪影可分为层状伪影、阶梯状伪影、模糊伪影等。结论64层螺旋CT冠状动脉成像的可评估率较高，但由于患者自身或扫描的原因会出现影响图像诊断的伪影，对这些伪影的成因及特点进行分析有助于提高冠状动脉CT血管造影的成功率及避免假阳性的诊断。     

Inhibition of delayed rectifier K(+)-current by levcromakalim in single intestinal smooth muscle cells: effects of cations and dependence on K(+)-flux.

1. Whole-cell voltage-clamp recordings were made from single smooth muscle cells isolated from the longitudinal layer of the guinea-pig small intestine. 2. Levcromakalim ((-)Ckm) inhibited delayed rectifier K-current (IK(DR)) and induced a voltage-independent K-current (IK(-Ckm)). Both effects were inhibited similarly by glibenclamide. In some cells, however, IK(-Ckm) could be induced without any effect on IK(DR). 3. Ba2+ caused a voltage-dependent block of IK(-Ckm). The IC50 was 0.2 mM at -40 mV (6 cells), but at 0 mV 2 mM Ba2+ caused only a 26 +/- 7% inhibition (n = 5). Ba2+ had much less effect on IK(DR), 2 mM Ba2+ having no inhibitory effect on current elicited by depolarization to -30 mV (n = 6) or 0 mV (n = 5). 4. Low concentrations of Zn2+ blocked IK(-Ckm) while having little effect on IK(DR). Zn2+ (40 microM) caused a 77 +/- 1% reduction of IK(-Ckm) at -30 mV (n = 4) but IK(DR) was inhibited by only 10 +/- 3% at the same voltage (n = 4). 5. Inward current amplitudes were compared in 135 mM Rb+ and 135 mM K+ bath solutions. (-)Ckm-activated Rb(+)-current was only 4% of the K(+)-current, whereas delayed rectifier Rb(+)-current was larger than K(+)-current. 6. (-)Ckm did not inhibit IK(DR) if IK(-Ckm) was blocked. In the presence of 2 mM Ba2+ or 135 mM Rb+, (-)Ckm did not induce current nor did it inhibit the delayed rectifier.(ABSTRACT TRUNCATED AT 250 WORDS)     

低磁场MRI伪影的处理及图像优化方法

目的了解各种不同原因产生的伪影及图像特征,选择合理的扫描参数和序例,提高和改善图像质量。方法分析产生伪影的原因,采取相应的方法重新扫描对比。结果分析伪影的种类归宿,可采取相应补偿技术,使图像质量能更加提高。结论成像时有效处理伪影和优化可达到为临床应用提供较精确的影像信息的目的。     

Temporal Changes in Tissue Repair Permit Survival of Diet-Restricted Rats from an Acute Lethal Dose of Thioacetamide

Although, diet restriction (DR) has been shown to substantiallyincrease longevity while reducing or delaying the onset of agerelateddiseases, little is known about the mechanisms underlying thebeneficial effects of DR on acute toxic outcomes. An earlierstudy (S. K. Ramaiah et al., 1998, Toxicol. Appl. Pharmacol.150, 12–21) revealed that a 35% DR compared to ad libitum(AL) feeding leads to a substantial increase in liver injuryof thioacetamide (TA) at a low dose (50 mg/kg, ip). Higher liverinjury was accompanied by enhanced survival. A prompt and enhancedtissue repair response in DR rats at the low dose (sixfold higherliver injury) occurred, whereas at equitoxic doses (50 mg/kgin DR and 600 mg/kg in AL rats) tissue repair in AL rats wassubstantially diminished and delayed. The extent of liver injurydid not appear to be closely related to the extent of stimulatedtissue repair response. The purpose of the present study wasto investigate the time course (0–120 h) of liver injuryand liver tissue repair at the high dose (600 mg TA/kg, ip,lethal in AL rats) in AL and DR rats. Male Sprague-Dawley rats(225–275 g) were 35% diet restricted compared to theirAL cohorts for 21 days and on day 22 they received a singledose of TA (600 mg/kg, ip). Liver injury was assessed by plasmaALT and by histopathological examination of liver sections.Tissue repair was assessed by [³H]thymidine incorporation intohepatonuclear DNA and proliferating cell nuclear antigen (PCNA)immunohistochemistry during 0–120 h after TA injection.In AL-fed rats hepatic necrosis was evident at 12 h, peakedat 60 h, and persisted thereafter until mortality (3 to 6 days).Peak liver injury was approximately twofold higher in DR ratscompared to that seen in AL rats. Hepatic necrosis was evidentat 36 h, peaked at 48 h, persisted until 96 h, and returnedto normal by 120 h. Light microscopy of liver sections revealedprogression of hepatic injury in AL rats whereas injury regressedcompletely leading to recovery of DR rats by 120 h. Progressionof injury led to 90% mortality in AL rats vs 30% mortality inDR group. In the surviving AL rats, S-phase DNA synthesis wasevident at 60 h, peaked at 72 h, and declined to base levelby 120 h, whereas in DR rats S-phase DNA synthesis was evidentat 36 h and was consistently higher until 96 h reaching controllevels by 120 h. PCNA studies showed a corresponding increasein cells in S and M phase in the AL and DR groups. DR resultedin abolition of the delay in tissue repair associated with thelethal dose of TA in ad libitum rats. Temporal changes and highertissue repair response in DR rats (earlier and prolonged) arethe conduits that allow a significant number of diet restrictedrats to escape lethal consequence.     

心电图伪差产生的因素分析及解决办法

目的分析心电图伪差产生的原因，找出减少伪差的方法，为临床心电图检查提供质量保证。方法对918例职工体检心电图伪差产生原因分析、总结。结果通过完善操作方法、排除心电图机本身故障、排除外界偶然因素干扰等，可以改善心电图检查质量。结论通过排除心电图机本身故障、完善操作方法、排除外界偶然因素干扰等，可以减少伪差，改善心电网检查质量。     

我院药房退药原因分析与建议

目的:为提高医院服务质量、减少退药现象提供参考。方法:收集2009年1月-2010年12月我院药房(西药房)退药处方417张,以《医疗机构药事管理规定》为依据,分析其退药原因,并提出建议。结果与结论:退药原因包括医师原因(148张,35.49%)、药房原因(96张,23.02%)、患者原因(77张,18.47%)、药品不良反应(41张,9.83%)、收费员录入错误(25张,6.00%)、病房更改医嘱(20张,4.80%)、计算机系统方面原因(10张,2.40%)。建议通过健全各项规章制度、完善各科室岗位标准操作规程、加强人才队伍建设、优化工作流程、加强团队合作等措施减少退药现象。     

DR组织均衡技术在胸腰段脊柱骨折中的应用价值

目的探讨胸腰段脊柱外伤患者数字X线摄影（DR）中,采用组织均衡技术的DR图像与标准DR图像的差别。方法抽取200例胸腰段脊柱外伤患者DR影像图像作为分析材料,比较运用组织均衡技术所得到的图像与标准DR图像的差别。结果采用组织均衡技术处理后的DR图像与标准DR图像在胸腰段脊柱骨折显示率上有较大区别,差别有统计学意义。结论DR组织均衡技术在胸腰段脊柱骨折诊断中有较大的临床应用价值。     

Diet restriction modulates lung response and survivability of rats exposed to ozone

Ozone (O(3)) is a powerful oxidant component of photochemical smog polluting the air of urban cities. Exposure to low-level O(3) causes lung injury and increased morbidity of the sensitive segment of population, and exposure to high levels can be lethal to experimental animals. Injury from O(3) exposure is generally associated with free radical formation and oxidative stress. Because diet restriction is proposed to enhance antioxidant status, we examined whether it would influence the response to inhaled O(3). Twenty-four Sprague-Dawley rats, 1 month old, weighing 150 g, were divided into two dietary regimens (12 rats/regimen); one was freely-fed (FF), and the second was diet-restricted (DR) to 20% the average daily intake of the FF. After 60 days of dietary conditioning, the body weight of DR rats was reduced to 50% that of FF rats. Then, in one experiment, two groups (six rats/group), one FF and the other DR, were exposed to 0.8+/-0.1 p.p.m. (1570+/-196 microg/m(3)) O(3), continuously for 3 days. Another two similar groups of rats were exposed to filtered room air and served as matched controls. After exposure, all rats were euthanized and the lungs analyzed for biochemical markers of oxidative stress. In a second experiment, 24 rats were divided into two groups (12 rats/group), one FF and the other DR, then exposed to high-level O(3) for 8 h (4 p.p.m., 7848+/-981 microg/m(3)) and the mortality noted during exposure and for 16 h post-exposure. Following low-level O(3), inhalation, greater alterations were observed in FF rats compared with DR rats. With high-level O(3) exposure, DR rats exhibited a much greater survivability compared with FF rats (90% versus 8%, respectively). These observations suggest that diet restriction leading to significant reduction of body weight is beneficial, and may play a role in the resistance to the adverse effects of O(3).     

320排动态容积CT诊断肋骨隐匿性骨折的价值

目的探讨320排CT诊断肋骨隐匿性骨折的价值。方法回顾性分析35例临床怀疑肋骨骨折,而数字化X线摄影显示为阴性的病例,进一步行320排螺旋CT扫描,并行重建后处理,分析所得图像。结果 35例数字化X线摄影均未见明确肋骨骨折,而320排CT检出81处骨折,其中单发骨折11例(31.4%),多发骨折24例(68.6%)。结论 320排CT显示肋骨无错位细微骨折优于数字化X线摄影,可作为肋骨隐匿性骨折的首选检查方法。