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141.
142.
Mark W Woolrich Peter Chiarelli Daniel Gallichan Joanna Perthen Thomas T Liu 《Magnetic resonance in medicine》2006,56(4):891-906
The study of brain function using MRI relies on acquisition techniques that are sensitive to different aspects of the hemodynamic response contiguous to areas of neuronal activity. For this purpose different contrasts such as arterial spin labeling (ASL) and blood oxygenation level dependent (BOLD) functional MRI techniques have been developed to investigate cerebral blood flow (CBF) and blood oxygenation, respectively. Analysis of such data typically proceeds by separate, linear modeling of the appropriate CBF or BOLD time courses. In this work an approach is developed that provides simultaneous inference on hemodynamic changes via a nonlinear physiological model of ASL data acquired at multiple echo times. Importantly, this includes a significant contribution by changes in the static magnetization, M, to the ASL signal. Inference is carried out in a Bayesian framework. This is able to extract, from dual-echo ASL data, probabilistic estimates of percentage changes of CBF, R(2) (*), and the static magnetization, M. This approach provides increased sensitivity in inferring CBF changes and reduced contamination in inferring BOLD changes when compared with general linear model approaches on single-echo ASL data. We also consider how the static magnetization, M, might be related to changes in CBV by assuming the same mechanism for water exchange as in vascular space occupancy. 相似文献
143.
目的 探讨营养支持在重症心脏瓣膜病外科治疗中的作用。方法2000年5月-2005年5月对182例重症心脏瓣膜病行瓣膜置换术,围术期采用营养支持疗法。其中单瓣病变74例,二尖瓣合并主动脉瓣病变108例。135例行三尖瓣成形术,37例行左房折叠术。结果 182例住院死亡5例,死亡率2.7%,术后并发低心排15例,死亡1例,随访151例,结论 科学的应用营养支持方案,可以明显地提高重症心脏瓣膜病外科手术成功率。 相似文献
144.
心血管造影在复杂和(或)复合先天性心脏病诊断中的应用 总被引:2,自引:0,他引:2
目的 探讨心血管造影在先天性心脏病(简称先心病)复杂和(或)复合畸形中的应用价值。方法 分析360例复杂和(或)复合畸形造影所见及其与超声心动图等临床检查的联系。结果 本组360例(包括75例肺动脉闭锁合并室间隔缺损、62例右室双出口、60例法乐四联症、52例单心室、42例大动脉错位、15例三尖闭锁、6例冠状动脉异常、5例完整型肺静脉畸形连接、5例完全型心内膜垫缺损、4例共同动脉干、3例室间完整的肺动脉闭锁、7例其他病例和24例外科术后检查)心血管造影和超声对比,纠正后者误、漏诊分别为34、30例及对合并畸形误诊16例。对复杂和(或)复合畸形中体肺侧支血管、冠状动脉畸形和肺动脉段分支及其异常的检测和诊断优于超声心动图,并可测量肺动、静脉压力及体肺侧支血管压力而优于其他影像学检查方法。结论 对于先心病复杂和(或)复合畸形的疑难病例诊断和鉴别诊断,尤其显示体、肺及冠状动脉分支的全貌及相关病变,以及测量肺动脉和心室压力等,心血管造影(含DSA)仍有重要或不可替代的作用。 相似文献
145.
外科学教学中的审美教育 总被引:1,自引:0,他引:1
医学审美教育是医学生全面素质教育不可分割的组成部分,笔者结合长期外科教学实践,阐述了在外科学教学中运用医学美学原理对外科学的美进行开发和挖掘,使医学生在熟练掌握外科学基本理论和基本技能的同时,潜移默化地接受美的教育,美的熏陶,更能激发他们对外科学的热爱和兴趣,达到全面提高医学生整体素质的目的。 相似文献
146.
147.
A Trakic F Liu H Sanchez Lopez H Wang S Crozier 《Magnetic resonance in medicine》2007,57(6):1119-1130
The switching of magnetic field gradient coils in magnetic resonance imaging (MRI) inevitably induces transient eddy currents in conducting system components, such as the cryostat vessel. These secondary currents degrade the spatial and temporal performance of the gradient coils, and compensation methods are commonly employed to correct for these distortions. This theoretical study shows that by incorporating the eddy currents into the coil optimization process, it is possible to modify a gradient coil design so that the fields created by the coil and the eddy currents combine together to generate a spatially homogeneous gradient that follows the input pulse. Shielded and unshielded longitudinal gradient coils are used to exemplify this novel approach. To assist in the evaluation of transient eddy currents induced within a realistic cryostat vessel, a low-frequency finite-difference time-domain (FDTD) method using the total-field scattered-field (TFSF) scheme was performed. The simulations demonstrate the effectiveness of the proposed method for optimizing longitudinal gradient fields while taking into account the spatial and temporal behavior of the eddy currents. 相似文献
148.
149.
在给病人使用化疗药物的过程中,护士不可避免地接触抗肿瘤药物,因而对自身健康产生危害。为了维护护士的健康,提高护理人员的防护意识,我们对肿瘤专科护士做一个防护调查,现将情况介绍如下。1临床资料与方法1.1临床资料选取山西省肿瘤医院临床一线,参加工作2年以上并经常接触化 相似文献
150.
Pulmonary Lophomonas blattarum infection in patients with kidney allograft transplantation 总被引:3,自引:0,他引:3
Yong Wang Zheng Tang Shuming Ji Zhen Zhang Jinsong Chen Zhen Cheng Dongrui Cheng Zhihong Liu Leishi Li 《Transplant international》2006,19(12):1006-1013
The aim of the study was to analyse the clinical manifestation and management of pulmonary Lophomonas blattarum infection in four allograft transplantation recipients retrospectively. Four patients with pulmonary L. blattarum infection were diagnosed by using Fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) examination. Their clinical manifestation and management are summarized. Four cases of pulmonary L. blattarum were found during the period from the second month to the third month after transplantation. Concurring infection by other pathogens was found in three of them. Common initial symptoms included fever (>38 degrees C) without cough and breathlessness. Lower lobe shadowing could be found on chest X-ray. Body temperature decreased to the normal range in three patients and to 37.5 degrees C in the other one, after intravenous injection of metronidazole and tapering immunosuppressant. Radiological examination confirmed improved health condition of the patients afterwards. Two patients received repeated FOB and only dead L. blattarum was found. Pulmonary L. blattarum infection in allograft transplant recipients carry relatively obscure initial symptoms. Possible L. blattarum infection needs to be screened in post-transplantation pulmonary infection patients with similar symptoms, especially in those who respond poorly to anti-infection treatment. Microscopic examination of BAL fluid can help to identify pulmonary L. blattarum infection and metronidazole is an ideal treatment choice. 相似文献