Digital radiography of the chest

Digital radiography is an appropriate method for both bedside and in-department chest radiographs. Its major advantage in bedside chest radiography is its control of the displayed optical density of these radiographs. With dynamic range control processing, it improves the visibility of tubes and lines superimposed on the mediastinal tissues. When used for in-department chest radiography, it may offer slight advantages in the evaluation of disease in the mediastinum, but in general is equivalent to film-screen chest radiography. The main reasons for using digital chest radiography for in-department chest radiographs relate mainly to its use as a data entry point method of projection radiography for high-quality teleradiology or for its use in a picture archiving and communication system. Apart from these advantages, there is no reason to change from conventional to digital chest radiographs. Digital radiographs are, with certain systems, printed at smaller than life size. Because of this, there is a necessary period of learning as radiologists adjust to the new image size. The most important change in radiologists' work pattern appears to be the need to sit closer to the film. Findings of disease are smaller, but, with experience, just as easy to see.     

Comparison of 180° and 360° acquisition for myocardial perfusion SPECT with compensation for attenuation, detector response, and scatter: Monte Carlo and mathematical observer results

BACKGROUND: The optimal projection data acquisition strategy for myocardial perfusion (MP) single photon emission computed tomography (SPECT) remains controversial. METHODS: We compared MP SPECT using 180 degrees and 360 degrees projection data obtained with the same acquisition time, reconstructed either with filtered back projection (FBP) or the iterative ordered-subsets expectation maximization (OS-EM) algorithm with various combinations of attenuation, detector response, and scatter compensation using mathematical observers and a myocardial defect detection task. We used Monte Carlo-simulated projection data from a population of 3-dimensional nurbs-based cardiac-torso (NCAT) phantoms with ranges of variability in patient anatomy, organ uptake, defect location, defect size, and noise level based on clinical data. Projection data from 180 degrees and 360 degrees acquisitions were generated by assuming the same acquisition time. After iterative or FBP reconstruction, standard postprocessing methods were applied. For each acquisition and reconstruction method, we optimized the number of iterations and cut-off frequency of the Butterworth filter using the Channelized Hotelling Observer methodology. The optimum set of parameters was that which gave the maximum area under the curve. RESULTS: For both acquisition protocols, OS-EM with compensations provided better performance than FBP or OS-EM without compensation. For FBP, the optimized 180 degrees acquisition provided a statistically significant increase in AUC as compared with optimized 360 degrees acquisition. For OS-EM, the AUCs for 180 degrees were slightly larger than for 360 degrees acquisitions when comparing images reconstructed with the same compensations. However, the differences were smaller and not statistically significant. CONCLUSION: With optimized reconstruction and filtering parameters, 180 degrees acquisition provided a statistically significant improvement over 360 degrees acquisition for FBP reconstruction. However, for OS-EM the differences were small and not statistically significant.     

抗原激活红细胞和白细胞免疫反应主干道的实验研究

目的测定抗原对红细胞和白细胞免疫反应主干道的作用。方法癌细胞(5×106/ml)和(或)卡介苗(0·1mg)或酵母菌(5×108/ml)加到全血细胞悬液0·2ml(或白细胞0·2ml)和枸橼酸抗凝的新鲜血浆0·3ml(或生理盐水0·3ml)37℃温育1h,采用免疫酶联法检测IL-8水平。分组:①抗原(癌细胞或酵母菌或卡介苗)0·2ml加入全血细胞悬液0·2ml和血浆0·3ml;②生理盐水0·2ml加入全血细胞悬液0·2ml和血浆0·3ml;③抗原0·2ml加入白细胞悬液0·2ml和血浆0·3ml;④生理盐水0·2ml加入白细胞悬液0·2ml和血浆0·3ml。结果癌细胞、卡介苗和酵母菌能激活血液免疫反应,但没有加血浆组中,这些抗原不能激活血液免疫反应,在这些抗原加入全血细胞和血浆组,IL-8激活指数(2·124±0·860)明显高于这些抗原加入白细胞和血浆组的IL-8激活指数(0·390±0·080),P<0·01。结论结果表明在血液免疫反中存在红细胞和白细胞免疫反应主干道路线图,红细胞和补体在血液免疫反应路线图中具有重要作用。     

Reassessment of the accuracy of traditional sperm characteristics and adenosine triphosphate (ATP) in estimating the fertilizing potential of human semen in vivo

Receiver operating characteristic curves and accuracy parameters were computed for traditional sperm characteristics (concentration, motility, morphology) and the number of peroxidase negative cells, and the concentration of adenosine triphosphate (ATP) in semen from populations of fertile and infertile men, and men who achieved a pregnancy after varicocele treatment. The percentage and concentration per millilitre of spermatozoa with rapid linear progressive motility, and the ATP concentration, provided the best discrimination between fertile and treated fertile from infertile men. The misclassification rate was higher for sperm morphology, total progressive motility and viability, whereas sperm concentration and the total sperm count per ejaculate had the worst discriminating power. The number of peroxidase negative cells per 100 spermatozoa was highly specific in identifying men who achieved pregnancy after varicocele treatment. The lower limit of normality of sperm characteristics was remarkably different between fertile men and men achieving pregnancy after treatment or during infertility work-up.     

计算机辅助检测对检出乳腺X线片中成簇微钙化灶的价值

目的:探讨计算机辅助检测系统(CAD)对检出乳腺X线钼靶摄影片中成簇微钙化灶的临床应用价值。方法:将22例乳腺X线钼靶片上疑有簇状钙化灶患者和13例正常对照者的140张乳腺钼靶X线片,经专业扫描仪数字化处理后,应用CAD软件标记其中的微钙化灶,由6位放射科医师分别单独阅片,再结合CAD阅片,结果采用受试者操作特性(ROC)曲线法进行分析。结果:6位放射科医师结合CAD阅片后,评价效果均优于未结合CAD时,其中3位低年资医师(有1年临床经验)和1位中年资医师(有5年以上临床经验)的两次评价结果有显著性差异(P<0.05)。结论:CAD有助于提高乳腺X线片中成簇微钙化灶的检出率,尤其对缺少诊断经验医师的作用更大。     

Storage phosphor digital mammography

Digital mammography using storage phosphor CR is still in the investigational stage. It is the only digital mammography system that has been tested in preliminary clinical trials with promising early results. Further clinical studies are needed to assess the impact of the limited spatial resolution of storage phosphor technology on its application as a digital screening mammography system. Further studies also are needed to determine the optimum image processing parameters needed in digital mammography.     

应用力学因素检测膝关节功能的实验研究

目的研究应用力学因素检测膝关节功能方法的有效性.方法利用测力平台测量得到人体下肢在运动过程中的力学曲线,用数学方法确定力学曲线的最大值F和曲线特征值R.结果给出51例骨关节炎患者的分析数据,并给出30例正常人的结果作为对照.结论应用力学因素可以有效地检测膝关节功能状态.     

POEMS综合征5例临床分析

目的:总结POEMS综合征的临床特征,提高对POEMS综合征的诊疗认识。方法:回顾性分析5例PO-EMS综合征的一般资料、临床表现、辅助检查、治疗及预后等。结果:5例患者主要临床表现均有多发性周围神经病变、皮肤损害、水肿、不同程度的肝脾肿大及内分泌病变。治疗以激素及免疫球蛋白为主,预后多不良。结论:POEMS综合征是一种累及多系统的疾病,与浆细胞病关系密切,临床表现复杂多样,目前认识尚有不足,应注意多系统检查提高临床诊疗水平。     

神经精神性狼疮临床资料分析

目的探讨神经精神性狼疮的临床特点。方法以神经精神性狼疮或狼疮脑病为检索词,检索2000年~2006年国内公开发表的中文文献,选取其中有关临床分析及诊断的文献进行临床分析。结果神经精神性狼疮发生率占系统性红斑狼疮患者的15.1%,男女性别比约为1∶12,平均年龄31岁。神经精神症状以头痛(40.4%),癫痫发作(32.9%),意识障碍(21.8%),精神行为异常(12.8%)最多见;其他临床症状有发热(62.2%),关节疼痛(46.0%),面部红斑或皮肤损害(34.7%),肾损害(20.7%);脑电图约61%异常,颅脑CT有45.8%局灶或弥漫异常,MRI有66.7%弥漫性异常;抗核抗体阳性率49.2%,抗双链DNA阳性率33.4%。结论神经精神性狼疮以青年女性多见,常累及全身多系统和器官,诊断主要依据临床表现,影像学、血清抗体检查有一定参考价值,但特异性不高。