乳腺DR成像普通模式和精细模式成像性能对比

目的对数字乳腺X射线摄影的两种不同曝光模式（精细模式和普通模式）成像性能进行评价。方法采用乳腺成像体模,选择不同的阳极滤过器组合,分别在两种自动曝光模式下成像,测量图像信噪比和腺体吸收剂量,并引入图像品质因数综合评价成像性能的好坏。结果精细模式图像信噪比要高于普通模式,但使腺体吸收剂量增加,因而品质因数低于普通模式。结论在临床使用中必须充分考虑临床实际需要来选择相应的成像技术,在保证临床图像质量的同时尽量降低受检者的辐射风险。     

GE Revolution XR/d DR旋转阳极故障维修一例

本文介绍了一例GERevolution XR/d DR旋转阳极启动故障的分析与维修方法。     

DR的铜滤过技术在胸部高千伏摄影中的应用

目的 探讨DR的铜滤过技术在胸部高千伏摄影中的应用价值。方法 使用三种不同厚度的铜(0.1mm、0.2mm、0.3mm)作滤过和不使用铜滤过作胸部的高千伏摄影,在相同厚度的铜滤过,不同体厚的患者,在相同的摄影条件、获得同等图象质量情况下进行比较。测算每种方式病人接受的体表剂量、单位面积的受射量。结果 使用铜(0.1mm、0.2mm、0.3mm)滤过和不使用铜滤过在相同的摄影条件、获得同等图象质量,患者接受的X射线剂量分别是原来的24%、32%、38%。对同一厚度的铜滤过,不同体厚的高千伏摄影,其X射线减少的差异不明显。体厚越大,滤过厚度越厚,X射线减少就越明显。结论 在患者接受放射线检查时,合理使用铜滤过技术,使患者受到的X射线损害最小。同时也减少了群体的射线损害,为整体的放射防护起到一个积极作用。     

附加滤过在婴幼儿胸部DR摄影中降低辐射剂量的价值

目的探讨附加滤过在婴幼儿胸部DR摄影中降低辐射剂量的应用价值。方法随机选择我院120名就诊婴幼儿,按照附加Cu滤过0、0.1、0.2、0.3 mm平均分4组进行DR摄影,曝光参数:0~1岁70kVp,1~2岁80kVp,2~3岁90kVp,SID=100cm,speed=600。采用小焦点200mA,自动曝光控制系统曝光,评价图像质量,记录图像信息中入射体表剂量进行统计学分析。结果各滤过组间入射体表剂量统计学比较存在显著差异P<0.01,0.1、0.2、0.3 mmCu滤过分别是无滤过的64.18%、51.12%、42.54%。4组附加滤过影像质量比较P>0.05无明显差异。结论利用附加滤过,采用自动曝光控制系统可降低婴幼儿胸部DR摄影辐射剂量。     

不同靶与滤过材料组合对乳腺摄影图像质量影响的实验分析

目的 对乳腺机不同靶、滤过组合的图像质量进行对比。方法 选择三种不同的靶、滤过组合,在半自动曝光模式下,对乳腺模体曝光成像,测量体表入射剂量,图像按ACR标准评价。结果 Mo/Mo组合剂量最高、分辨率最好,Mo/Rh居中,W/Rh组合剂量最低、分辨率最低。结论 临床使用中应充分考虑实际需要来选择曝光技术,保证图像质量的同时尽量降低受检者的辐射风险。     

DR成像技术对比传统X线摄影的应用优势

目的：探讨DR与传统拍片技术在临床应用中的优势。方法：从系统的构成、工作原理、临床应用、主要特点相对比得出DR在临床应用中的优势。结论：DR能够提高影像质量,减轻辅助科室工作人员的劳动强度,值得推广。     

数字乳腺X射线摄影中不同靶/滤过组合对辐射剂量的影响

目的 探讨数字乳腺X射线机应用Mo/Mo、Mo/Rh、W/Rh 3种不同靶滤过组合对辐射剂量的影响,以便优化选择摄影技术参数,降低受检者的辐射损伤。方法 应用Siemens MAMMOMAT Inspiration数字乳腺X射线机,Ray Safe X射线质量检测仪。首先使用全自动曝光模式对不同厚度的PMMA模体进行曝光并记录管电流量、管电压等摄影参数,然后采用相同的管电压、管电流量、压迫厚度在不同的靶滤过组合(Mo/Mo、Mo/Rh、W/Rh)模式下进行手动曝光,读取并记录体表入射剂量(ESD),计算平均腺体剂量(AGD)。对不同模体厚度在使用3种不同靶滤过组合时产生的平均腺体剂量进行随机区组的方差分析,采用线性相关和回归观察不同靶滤过组合及不同厚度与AGD的相关性并列出直线回归方程。结果 3种靶滤过组合对不同厚度模体产生的AGD差异有统计学意义,Mo/Mo组合的AGD最高,W/Rh组合的AGD显著降低。使用不同靶滤过组合时模体厚度与AGD均呈显著正相关。结论 W/Rh组合AGD明显低于其他两种组合,乳腺X射线摄影时采用W/Rh组合是最佳选择,可显著降低受检者的辐射剂量。     

降低小儿胸部DR摄影辐射剂量的研究

目的:降低小儿胸部数字X线摄影(DR)辐射剂量,探索最优化的曝光参数。方法:通过设置附加铜滤过(0～0.3mm)和管电压(60～100kVp),采用自动曝光控制(AEC)先在等效小儿胸部的水模上放置线对卡进行卧位DR摄影,然后对各组图像进行空间分辨力、噪声水平评价,同时记录入射体表剂量和mAs。选最优化摄影参数对30例患儿进行胸部正位摄影,评价图像质量。结果:①各组图像分辨力辨认最高为2.5LP/mm,各组图像背景噪声均能接受;②采用0.3mm铜滤过入射体表剂量均低于其他滤过组,差异有统计学意义(q=5.368,q=2.29,q=2.98;P<0.05);③附加滤过相同,管电压为60～80kVp,入射体表剂量随kVp增加逐渐降低,当管电压为80～100kVp时则略有增加;④相同kVp时附加滤过增厚,入射体表剂量降低,管电流增加;⑤30例患儿胸部正位摄影图像均符合诊断标准。结论:设置管电压80kVp,0.3mm铜附加滤过,采用AEC进行小儿胸部DR为最优化摄影方案,可以降低小儿入射体表剂量。     

数字化钼、铑双靶乳腺摄影中患者吸收剂量的比较

目的 探讨钼、铑靶面及钼、铑滤过板在数字化乳腺摄影中对患者吸收剂量的影响。方法 收集临床137例患者的548次曝光技术参数,比较不同靶/滤板摄影,乳腺组织的平均吸收剂量,并求出每一次乳腺检查的平均剂量值。结果 钼靶/钼滤板摄影,患者的吸收剂量较高,而铑靶/铑滤板患者剂量明显降低,两组之间差异有显著性(P <0.05)。结论 根据乳腺厚度及腺体致密程度选择合适的靶/滤板组合进行乳腺摄影,既能保证图像质量,又能降低患者吸收剂量。     

基于LabVIEW的微波热声信号采集及消噪处理

目的:研究微波热声成像中多通道的大数据量热声信号的采集保存和消除背景噪声的方法。方法:基于Lab-VIEW软件编程实现数据的采集与保存,并通过LabVIEW和C语言混合编程实现数字滤波,对热声信号中的强背景噪声进行消噪处理仿真实验。结果:数字平均滤波能够有效消除微波热声信号中的噪声,提高信噪比。结论:该方法可以有效地用于绝大部分具有周期特性的微弱信号提取和消噪处理。     

数字心电图机检定装置的研制及检定方法的研究

为了保证临床在用数字心电图机的准确可靠,确定其计量特性、检定方法及研制相应的检定装置非常必要,详细阐述了数字心电图机检定装置的组成、技术指标、原理框图、关键技术以及数字心电图机的主要检测项目,可指导数字心电图机检测工作的开展.     

Bayesian procedures for phase I/II clinical trials investigating the safety and efficacy of drug combinations

Many formal statistical procedures for phase I dose-finding studies have been proposed. Most concern a single novel agent available at a number of doses and administered to subjects participating in a single treatment period and returning a single binary indicator of toxicity. Such a structure is common when evaluating cytotoxic drugs for cancer. This paper concerns studies of combinations of two agents, both available at several doses. Subjects participate in one treatment period and provide two binary responses: one an indicator of benefit and the other of harm. The word 'benefit' is used loosely here: the response might be an early indicator of physiological change which, if induced in patients, is of potential therapeutic value. The context need not be oncology, but might be any study intended to meet both the phase I aim of establishing which doses are safe and the phase II goal of exploring potential therapeutic activity. A Bayesian approach is used based on an assumption of monotonicity in the relationship between the strength of the dose-combination and the distribution of the bivariate outcome. Special cases are described, and the procedure is evaluated using simulation. The parameters that define the model have immediate and simple interpretation. Graphical representations of the posterior opinions about model parameters are shown, and these can be used to inform the discussions of the trial safety committee.     

离散选择实验模型在卫生人力资源研究中的应用

目的整合目前国内外离散选择实验模型（DCE）在卫生人力资源研究中的运用情况,以及DCE在人力资源研究中的优缺点和初步效果。方法通过对目前国内外一些研究的回顾,在概念、运用方法和步骤等方面进行了总结。结果研究发现,DCE可运用于测量医疗卫生工作者的工作意向,研究某一项工作特征的改变对选择工作的影响程度和某一项工作中某个属性特征水平的货币价值。建议在卫生人力资源研究中,可以利用DCE帮助进行相关的卫生政策的制定和实施。     

A novel Phase I/IIa design for early phase oncology studies and its application in the evaluation of MK-0752 in pancreatic cancer

The Cancer Research UK study CR0720-11 is a trial to determine the tolerability and effect on survival of using two agents in combination in patients with advanced pancreatic cancer. In particular, the trial is designed first to identify the most suitable combination of doses of the two agents in terms of the incidence of dose-limiting toxicities. Then, the survival of all patients who have received that dose combination in the study so far, together with additional patients assigned to that dose combination to ensure that the total number is sufficient, will be analysed. If the survival outcomes show promise, then a definitive randomised study of that dose combination will be recommended. The first two patients in the trial will be treated with the lowest doses of each agent in combination. An adaptive Bayesian procedure based only on monotonicity constraints concerning the risks of toxicity at different dose levels will then be used to suggest dose combinations for subsequent patients. The survival analysis will concern only patients who received the chosen dose combination, and will compare observed mortality with that expected from an exponential model based on the known survival rates associated with current treatment. In this paper, the Bayesian dose-finding procedure is described and illustrated, and its properties are evaluated through simulation. Computation of the appropriate sample size for the survival investigation is also discussed.     

艾滋病感染妇女感受的歧视及其对利用预防母婴传播服务的影响

目的了解某少数民族地区艾滋病感染妇女面临的社会心理问题,尤其是侮辱和歧视的感觉,分析对其利用预防艾滋病母婴传播服务的影响。方法采用定性调查方法,通过深入访谈和现场观察来获取研究资料。结果艾滋病感染妇女面临的最大社会心理问题是侮辱和歧视,分别来自医务人员、社区人员、家庭成员和她们自己。其中来自医务人员的歧视,对艾滋病感染妇女利用预防艾滋病母婴传播服务的影响最大。结论减少社会特别是医务人员的歧视,可以提高艾滋病感染妇女对预防艾滋病母婴传播服务的利用。     

Immune responses elicited by a fourth dose of the HPV-16/18 AS04-adjuvanted vaccine in previously vaccinated adult women

Background

Vaccines are now available for the prevention of HPV-16/18-related cervical infections and pre-cancers, primarily targeting adolescent girls. Since the risk of HPV exposure potentially persists throughout a woman's sexual life, vaccine-derived immunity should be long-term. The current study, HPV-024 (NCT00546078, http://clinicaltrials.gov), assessed the immune memory in North American women who received three doses of HPV-16/18 AS04-adjuvanted vaccine 7 years earlier in HPV-001 (NCT00689741).

Methods

Women vaccinated in HPV-001 received a 4th-dose of the HPV-16/18 vaccine (024-4DV group, N = 65). Post 4th-dose immune responses were compared with post 1st-dose immune responses in cross-vaccination controls (024-3DV group, N = 50). Reactogenicity was compared between the 4th-dose and the 1st-dose administration.

Results

Pre 4th-dose, 100% of subjects in the 024-4DV group remained seropositive for anti-HPV-16/18 antibodies (ELISA). Compared to pre 4th-dose, GMTs for anti-HPV-16 and anti-HPV-18 antibodies were respectively 9.3-fold and 8.7-fold higher at day 7, and 22.7-fold and 17.2-fold higher at month 1. Compared to post 1st-dose, GMTs for anti-HPV-16 and anti-HPV-18 were respectively 80.5-fold and 205.4-fold higher at day 7, and 11.8-fold and 20.5-fold higher at month 1. Furthermore, 68.2% and 77.3% of women had HPV-16/18 specific memory B-cells, respectively, pre 4th-dose, rising to 100% one month post 4th-dose vaccination. The 4th-dose was generally well tolerated.

Conclusion

A 4th-dose of HPV-16/18 AS04-adjuvanted vaccine triggered a rapid and strong anamnestic response in previously vaccinated women, demonstrating vaccine-induced immune memory.     

Estimating the contribution of inhalation exposure to di-2-ethylhexyl phthalate (DEHP) for PVC production workers,using personal air sampling and urinary metabolite monitoring

Because of troubling reports of high urinary metabolite levels and adverse reproductive health effects in workers exposed to di(2-ethylhexyl)phthalate (DEHP) in occupational settings, concern about exposure to DEHP in occupational settings is increasing. However, the contributions of different routes of exposure to DEHP are unclear. We used personal air sampling and biomonitoring to determine the contribution of inhalation exposure to the body burden of DEHP in the workplace. Eighty-nine workers (high-exposure group: 66 raw-materials workers; low-exposure group: 23 administrative workers) were recruited from three polyvinyl chloride (PVC) factories. Urinary levels of mono(2-ethylhexyl) phthalate (MEHP), (mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were measured in pre-shift and post-shift samples. The geometric means of airborne concentrations of DEHP were 5.3 μg/m³ (low-exposure group) and 32.7 μg/m³ (high-exposure group) (P < 0.01). Correlation analysis showed a consistently significant association between airborne DEHP concentration and urinary DEHP metabolite levels in the high-exposure group. Calculating daily DEHP intake based on total urinary metabolite levels showed that the geometric means of total daily urinary metabolite levels of DEHP were 9.2 μg/kg/day (low-exposure group) and 15.5 μg/kg/day (high-exposure group) (P < 0.01). A quartile analysis of all workers showed a significant trend toward an association between the individual contribution of inhalation exposure to DEHP and urinary DEHP metabolite levels, for which the mean inhalation contribution was 46.7% in the highest quartile. We conclude that inhalation-absorbed airborne DEHP significantly increased the total body burden of DEHP in these occupationally exposed workers.