Two-dimensional coronary MRA: limitations and artifacts

Our purpose was to assess image quality and interpretation problems of two-dimensional (2D) coronary MR angiograms. The coronary arteries of 27 subjects (12 normal volunteers and 15 patients) were evaluated with 2D coronary MR angiography (MRA). Coronary MRA was performed with a fat-suppressed electrocardiographically gated breath-hold gradient-echo sequence with k-space segmentation using a 1.5-T imager. Image quality throughout the study was occasionally degraded by: image ghosting (22%), ringing (19%), and/or blurring (22%) and incomplete fat-suppression (19%). Intermittent difficulties with breathholding were encountered in 44% of subjects. When limiting the analysis to those images with optimal image quality, interpretative difficulties were sometimes found: misregistration due to inconsistent breathholding (37%); difficulty in distinguishing veins from arteries (37%); obscured anatomy due to overlapping structures (26%); and poor visualization of portions of the left main coronary artery (59%). Two-dimensional coronary MRA studies have image quality and interpretive problems which need to be understood and addressed before routine clinical scanning is initiated.Correspondence to: A. J. Duerinckx     

血液白细胞图象的计算机自动分割方法研究

本文提出了一套血液白细胞图象的计算机自动分割方法。实际测试表明：该方法稳定可靠且有效。单个白细胞检出成功率达９６％，区域分割吻合率平均达９４％，现已将该方法装入作者研制的白细胞自动分类识别ＬＥＵＫ分析系统的分割模块中。     

319例小儿损伤和中毒外部原因分析

目的寻求小儿损伤和中毒意外事故发生的主要原因,以利于社会性的综合防治。方法将319例0~14岁小儿损伤和中 毒的外部原因分为11类,并按百分比从大到小排列,进行因素分析。结果得出损伤和中毒外部原因的排位。结论普及安全知识,特 别是增强小儿监护人和小孩的安全意识,才能减少事故的发生,。     

生脉散多糖的组成及其初级结构分析

目的：研究复方中药制剂中多糖与单方多糖之间的组成关系，以及生脉散多糖的初级结构分析。方法：提取和精制了生脉散（SMS）单方药材红参、麦冬、五味子中多糖成分；然后采用Sephadex G-75柱层析分离纯化SMS多糖，得一浅黄色SMS多糖纯品，经紫外光谱、Sephadex G－200凝胶柱层析和琼脂糖凝胶电泳检测证明为均一组分。同时采用Sephadex G-200凝胶柱层析，测得SMS多糖组成。运用TLC法和HPLC法测定了SMS多糖纯品的单糖组成；并采用IR，高碘酸氧化和Smith降解推知其初级结构。结果：SMS多糖由红参多糖，麦冬多糖和五味子多糖所组成，其中含有葡萄糖、L－鼠李糖、D－木糖、D－果糖、半乳糖和乳糖等多种单糖，主要糖苷键为α－构型；多糖糖苷键以1→4连接键为主，1→3为次。结论：首次报道了生脉散多糖的组成及其初级结构分析。     

对外伤性骨盆骨折摄影角度的探讨(附30例分析)

目的:探讨骨盆多发性骨折各部位的摄影角度及影像显示的原理及方法,优势与不足以及临床应用价值。方法:首先选择骨髂标本做研究对象进行不同角度的摄影,并选择了最佳摄影角度及方法,进行了30例患者的摄片,均符合临床诊断要求。结果:骨盆多发性骨折的各部位最适宜的摄影角度。骨盆入口位,摄影角度向头侧倾斜25°位;骨盆出口位,摄影角度向足侧倾斜25°位;髂骨及闭孔斜位,一侧抬高25°位,影像显示效果较佳,优于有关报导的摄影角度及方法。结论:对外伤性骨盆多发骨折的患者,各部位摄影角度上述所示,此方法可行,完全符合临床诊断要求。     

武汉市江岸区132名医生心态的调查与分析

调查分析了我市某医院132名医生在当前改革大潮中的心理态势，为医疗改革提供一定的科学依据。在调查中得知，医生，这个特定的社会角色，他们是积极向上的，发扬了“救死扶伤，实行革命人道主义”的精神，关心与促进了当前市场经济的改革。同时也要不断地创造一个宽松与和谐的工作、生活环境，不断地提高他们的专业技术水平和综合服务能力。     

Quantification of in-plane motion of the coronary arteries during the cardiac cycle: Implications for acquisition window duration for MR flow quantification

Motion of the coronary arteries during the heart cycle can result in image blurring and inaccurate flow quantification by MR. This condition applies particularly for longer acquisition windows that are typical of breath-hold coronary flow measurements. To determine the sensitivity of the technique to in-plane motion of different coronary arteries, the temporal variation in coronary position was measured in a plane perpendicular to the proximal portion of the vessel. The results indicated the presence of substantial displacement of the coronary arteries within the cardiac cycle, with a magnitude of motion approximately twice as large for the right as for the left coronary arteries. An estimation of the resulting vessel blurring was calculated, showing that the duration of the acquisition window for high spatial resolution coronary flow acquisitions should be less than 25 to 120 msec, depending on the specific coronary artery studied. In addition, these data specify optimal acquisition window placement for high resolution coronary angiography.     

Pulsed magnetization transfer spin-echo MR imaging

Cross relaxation between macromolecular protons and water protons is known to be important in biologic tissue. In magnetic resonance (MR) imaging sequences, selective saturation of the characteristically short T2 macromolecular proton pool can produce contrast called magnetization transfer contrast, based on the cross-relaxation process. Selective saturation can be achieved with continuous wave irradiation several kilohertz off resonance or short, intense 0° pulses on resonance. The authors analyze 0° binomial pulses for T2 selective saturation, present design guidelines, and demonstrate the use of these pulses in spin-echo imaging sequences in healthy volunteers and patients. Using the phenomenologic Bloch equations modified for two-site exchange, the authors derive the analytic expressions for water proton relaxation under periodic pulsed saturation of the macromolecular protons. This relaxation is shown to be monoexpo-nential, with a rate constant dependent on the saturation pulse repetition rate and the individual and cross-relaxation rates.     

急诊内科自杀未遂病人的临床特点

目的 收集和分析急诊内科自杀未遂病人的临床特点.方法 用自制的《自杀病人情况调查表》对2002年1月～2005年12月在我院急诊内科就诊自杀病人进行登记.结果 急诊内科自杀病人自杀方式以服药为主,服用安定者预后比较好,年龄越小越倾向于采取激烈的自杀方式;自杀者女多于男,男性服农药和灭鼠药的多,女性服安定的多.自杀者的平均年龄为35岁,男性大于女性.结论 急诊内科自杀未遂病人有其特定的临床特点.