FDG双探头符合成像与X线断层图像同机融合在胸腹部肿瘤病变诊断中的价值

目的 :初步评价FDG双探头符合成像与X线断层图像同机融合在胸腹部肿瘤病变诊断中的价值。材料和方法 :回顾性分析 2 2例疑为胸腹部肿瘤或肿瘤术后复发而行18F -FDG双探头符合成像与X线断层联合扫描同机图像融合患者的资料。结果 :14例肿瘤或肿瘤术后复发的患者FDG显像 ,在 34个病灶中共检出 33个病灶 ( 97.1% )。融合影像可更加直观清晰地显示占位性病变或肿大淋巴结的代谢活性。其中 4例 ( 4 /14 )患者位于邻近膈肌上下及胸椎体、前列腺的 6个病灶 ( 6 /34)必须借助融合图像才能精确定位。结论 :FDG双探头符合成像与X线断层图像同机融合可明显提高符合显像定位诊断的准确性。     

Auditory Oddball fMRI in Schizophrenia: Association of Negative Symptoms with Regional Hypoactivation to Novel Distractors

Schizophrenia is associated with abnormal processing of salient stimuli, which may contribute to clinical symptoms. We used fMRI and a standard auditory three-stimulus task to examine attention processing. Target stimuli and novel distractors were presented to 17 patients and 21 healthy controls and activation was correlated with negative and positive symptoms. To targets, patients overactivated multiple regions including premotor cortex, anterior cingulate, temporal cortex, insula, and hippocampus, and also showed attenuated deactivation within occipital cortex. To distractors, patients overactivated left ventrolateral prefrontal cortex. This overactivation may reflect hypersensitivity to salient stimuli in schizophrenia. Patients also exhibited an inverse correlation between negative symptom severity and activation to novel distractors in the dorsolateral prefrontal cortex, premotor area, and ventral striatum. Novelty-induced activity within prefrontal cortex and ventral striatum may represent a useful intermediate phenotype for studies of negative symptoms.     

Temporal Electrogram Analysis: Algorithm Development

PAUL, V.E., ET AL.: Temporal Electrogram Analysis: Algorithm Development. The automatic discrimination of physiological from pathological tachycardias by rate criteria alone lacks adequate specificity. Tachycardia detection algorithms based upon morphological analysis of the endocardial electrogram have been attributed high specificity although their specificity has not been proven. A previous study had shown temporal electrogram analysis TEA) to be an algorithm of high sensitivity in the detection of ventricular arrhythmias despite low computational demands. In this study, the specificity and potential for automatic implementation have been assessed. Manual adjustment of thresholds for individual patients gave a maximum potential sensitivity of 97% (26/27 arrhythmias correctly recognized as non-sinus). The use of automatic setting of thresholds reduced sensitivity to 81%. The specificity of the algorithm, as assessed by exercise testing, was only 60%.     

The differentiation of visually guided and anticipatory saccades in gap and overlap paradigms

Summary Saslow and others have shown that the latency of foveating saccades can be altered by changing the offset time of the current fixation point relative to the onset of the peripheral target. Whether anticipatory saccades contributed to these results was not known. By the criteria of direction error and amplitude error the minimum latency for visually guided saccades is 110–130 ms for three subjects and 160 ms for a longer latency subject. Excluding anticipatory responses did not eliminate offset-onset effects. The genesis of express saccades and the role of higher neural levels is discussed.     

An interactive dynamic analysis and decision support software for MR mammography

A fully automated software is introduced to facilitate MR mammography (MRM) examinations and overcome subjectiveness in diagnosis using normalized maximum intensity–time ratio (nMITR) maps. These maps inherently suppress enhancements due to normal parenchyma and blood vessels that surround lesions and have natural tolerance to small field inhomogeneities and motion artifacts. The classifier embedded within the software is trained with normalized complexity and maximum nMITR of 22 lesions and tested with the features of remaining 22 lesions. Achieved diagnostic performances are 92% sensitivity, 90% specificity, 91% accuracy, 92% positive predictive value and 90% negative predictive value. DynaMammoAnalyst shortens evaluation time considerably and reduces inter and intra-observer variability by providing decision support.     

基于威胁度的动态报警管理研究

IDS目前的主要问题之一是过高的误报率,这一方面给管理员增加了繁重的工作负担,从而使其可能忽视了系统中真正需要处理的关键攻击事件;另一方面,过高的误报率使得自动入侵响应,比如与防火墙联动,不能很好地执行下去.针对这个问题,提出了基于威胁度的动态报警管理TDAM模型,它通过对系统环境的感知分析报警信息,确定其威胁度.通过实验,可以得出TDAM框架能够比较好地进行报警评价、管理.     

Robust computer algorithm for detecting breaths in noisy ventilatory waveforms from infants

A computer-based algorithm to detect tidal breathing in long-term studies with little operator intervention is described. Recognition relies on matching the tidal signals to a set of three templates. A major consideration in the algorithm's design was its ability to detect, and, in some instances, to compensate for aberrations in the inspiratory/expiratory profiles. A test on a breath-by-breath basis of a sample of over 200 breaths in both quiet and active sleep in newborn infants showed that there was no significant difference between the algorithm-derived values for inspiratory and expiratory volumes and breath duration compared with those measured manually.     

PCR-SSCP检测巨噬细胞内结核分支杆菌耐药性的探讨

[目的]检测结核分枝杆菌耐药性。[方法]PCR检测分离分纯结核患者标本中巨噬细胞内TB-DNA,SSCP分析其耐药基因变异情况。[结果]PCR检测TB-DNA阳性率为90.8％;SSCP检测rpoB的耐药突变率为42.0％,KatG为30.4％,rpsL为42.0％。rpoB和KatG同时发生突变的机率为53.6％,rpoB和rpsL为47.7％,KatG和rpsL为50.7％,而rpoB、KatG和rpsL三者同时发生突变的机率为52.2％。[结论]分离分纯结核患者标本中巨噬细胞以PCR-SSCP测定其TB-DNA及其耐药性,可作为对结核病病原诊断和耐药情况判断的实用方法之一。     

Excimer laser corneal ablation: absence of a significant "incubation" effect.

Pulse-to-pulse consistency of excimer laser etching of cornea has been examined via two noncontact techniques: photoacoustic probe beam deflection, and time-resolved excimer pulse reflectometry. These methods clearly document the incubation phenomenon accompanying excimer laser ablation of polymethyl-methacrylate and the absence of the effect during polyimide ablation. In comparison, results for corneal ablation indicate consistent tissue etching over a train of pulses. Consequently, incubation appears to have negligible impact on corneal ablation.