997 resultados para lung imaging


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Background: Although there is evidence demonstrating an association between chronic obstructive pulmonary disease (COPD) and abdominal aortic aneurysm (AAA), it is not clear whether COPD predicts greater rates of expansion of established aneurysms. We sought such an association in a cohort of men with aneurysms detected in a population-based study of screening for aneurysms. Methods: In addition to regular aortic ultrasound scans, 179 men with AAA underwent full lung function testing in order to identify the presence of COPD and its subgroups, emphysema and other obstructive ventilatory defects (OVD). The rate of expansion of each aneurysm was calculated and the men were divided into 'rapid expanders' (3 mm or more per year) and 'slow expanders' (less than 3 mm per year). Any association with the presence of COPD or smoking was tested using a multivariate model. Results: Over a median follow-up period of 36 months the mean rate of aortic expansion for the cohort of 179 men was 2.1 mm/year. There was no significant difference in prevalence of COPD (68% overall) or having ever been a smoker (87% overall) between the rapid expanders and the slow expanders. Conclusions: Although there was a high prevalence of COPD among men with an AAA, there was no association between the rate of expansion of AAA and the presence of any form of this disease.

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Direct and simultaneous observation of root growth and plant water uptake is difficult because soils are opaque. X-ray imaging techniques such as projection radiography or Computer Tomography (CT) offer a partial alternative to such limitations. Nevertheless, there is a trade-off between resolution, large field-of-view and 3-dimensionality: With the current state of the technology, it is possible to have any two. In this study, we used X-ray transmission through thin-slab systems to monitor transient saturation fields that develop around roots as plants grow. Although restricted to 2-dimensions, this approach offers a large field-of-view together with high spatial and dynamic resolutions. To illustrate the potential of this technology, we grew peas in 1 cm thick containers filled with soil and imaged them at regular intervals. The dynamics of both the root growth and the water content field that developed around the roots could be conveniently monitored. Compared to other techniques such as X-ray CT, our system is relatively inexpensive and easy to implement. It can potentially be applied to study many agronomic problems, such as issues related to the impact of soil constraints (physical, chemical or biological) on root development.

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Background: All cases of lung cancer diagnosed in Western Australia in 1996 in which surgery was the primary treatment, were reviewed. Reported herein are the characteristics of the patients, the treatment outcomes and a comparison of the management undertaken with that recommended by international guidelines. Methods: All patients with a new diagnosis of lung cancer in Western Australia in the calendar year of 1996 were identified using two different population-based registration systems: the Western Australian (WA) Cancer Registry and the WA Hospital Morbidity Data System. A structured questionnaire on the diagnosis and management was completed for each case. Date of death was determined through the WA Cancer Registry. Results: Six hundred and sixty-eight patients with lung cancer were identified; 132 (20%) were treated with surgery. Lobectomy was the most frequently performed procedure (71%), followed by pneumonectomy (19%). Major complications affected 23% of patients. Postoperative mortality was 6% (3% lobectomy, 12% pneumonectomy). At 5 years the absolute survival was as follows for stage I, II, IIIA, IIIB, respectively: 51%, 45%, 12%, 5%. Conclusions: Investigations and choice of surgery in WA in 1996 reflect current international guidelines. The survival of patients with resectable lung cancer remains unsatisfactory.

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Ozone is a major air pollutant with adverse health effects which exhibit marked inter-individual variability. In mice, regions of genetic linkage with ozone-induced lung injury include the tumor necrosis factor-alpha (TNF), lymphotoxin-alpha (LTA), Toll-like receptor 4 (TLR4), superoxide dismutase (SOD2), and glutathione peroxidase (GPX1) genes. We genotyped polymorphisms in these genes in 51 individuals who had undergone ozone challenge. Mean change in FEV1 with ozone challenge, as a percentage of baseline, was -3% in TNF -308G/A or A/A individuals, compared with -9% in G/G individuals (p = 0.024). When considering TNF haplotypes, the smallest change in FEV1 with ozone exposure was associated with the TNF haplotype comprising LTA +252G/TNF -1031T/TNF -308A/TNF -238G. This association remained statistically significant after correction for age, sex, disease, and ozone concentration (p = 0.047). SOD2 or GPX1 genotypes were not associated with lung function, and the TLR4 polymorphism was too infrequent to analyze. The results of this study support TNF as a genetic factor for susceptibility to ozone-induced changes in lung function in humans, and has potential implications for stratifying health risks of air pollution.

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Objective: To determine the cost effectiveness of a magnetic resonance imaging scan (MRI) within 5 days of injury compared with the usual management of occult scaphoid fracture. Methods: All patients with suspected scaphoid fractures in five hospitals were invited to participate in a randomised controlled trial of usual treatment with or without an MRI scan. Healthcare costs were compared, and a cost effectiveness analysis of the use of MRI in this scenario was performed. Results: Twenty eight of the 37 patients identified were randomised: 17 in the control group, 11 in the MRI group. The groups were similar at baseline and follow up in terms of number of scaphoid fractures, other injuries, pain, and function. Of the patients without fracture, the MRI group had significantly fewer days immobilised: a median of 3.0 (interquartile range 3.0-3.0) v 10.0 (7-12) in the control group (p = 0.006). The MRI group used fewer healthcare units (median 3.0, interquartile range 2.0-4.25) than the control group (5.0, 3.0-6.5) (p = 0.03 for the difference). However, the median cost of health care in the MRI group ($594.35 AUD, $551.35-667.23) was slightly higher than in the control group ($428.15, $124.40-702.65) (p = 0.19 for the difference). The mean incremental cost effectiveness ratio derived from this simulation was that MRI costs $44.37 per day saved from unnecessary immobilisation (95% confidence interval $4.29 to $101.02). An illustrative willingness to pay was calculated using a combination of the trials measure of the subjects' individual productivity losses and the average daily earnings. Conclusions: Use of MRI in the management of occult scaphoid fracture reduces the number of days of unnecessary immobilisation and use of healthcare units. Healthcare costs increased non-significantly in relation to the use of MRI in this setting. However, when productivity losses are considered, MRI may be considered cost effective, depending on the individual case.

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Real-time ultrasound imaging provides an unrivalled opportunity to observe muscle morphology and contraction. This has obvious potential for clinical practice and the tool is beginning to be adopted into physical therapy. The implementation of ultrasound imaging has become particularly widespread for assessment of size and activation of deep trunk muscles, such as the transversus abdominis and lumbar multifidus, and for assessment of the pelvic floor muscles. The obvious benefit for these areas is that ultrasound permits observation of muscles that are difficult to assess through noninvasive means. This realization of the clinical potential of ultrasound imaging has been paralleled by an explosion of clinical and physiological research. However, despite the enthusiasm for utilization of ultrasound imaging, a question that is critical to address is whether ultrasound can actually improve rehabilitation.

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Morbidity and mortality from lung cancer is a major burden to global health. The integration of expert clinical experience, patient preference and high-quality evidence, including Cochrane systematic reviews, can only help improve outcomes from this highly lethal condition.

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A functional magnetic resonance imaging mental rotation paradigm was used to investigate the patterns of activation of fronto-parietal brain areas in male adolescents with attention-deficit hyperactivity disorder, combined type (ADHD-CT) compared with age-, gender-, handedness- and performance IQ-matched healthy controls. The ADHD-CT group had (a) decreased activation of the 'action-attentional' system (including Brodmann's areas (BA) 46, 39,40) and the superior parietal (BA7) and middle frontal (BA10) areas and (b) increased activation of the posterior midline attentional system. These different neuroactivation patterns indicate widespread frontal, striatal and parietal dysfunction in adolescents with ADHD-CT. Declaration of interest None.

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Asthma is characterized by pulmonary cellular infiltration, vascular exudation and airway hyperresponsiveness. Several drugs that modify central nervous system (CNS) activity can modulate the course of asthma. Amphetamine (AMPH) is a highly abused drug that presents potent stimulating effects on the CNS and has been shown to induce behavioral, biochemical and immunological effects. The purpose of this study was to investigate the effects of AMPH on pulmonary cellular influx, vascular permeability and airway reactivity. AMPH effects on adhesion molecule expression, IL-10 and IL-4 release and mast cell degranulation were also studied. Male Wistar rats were sensitized with ovalbumin (OVA) plus alum via subcutaneous injection. One week later, the rats received another injection of OVA-alum (booster). Two weeks after this booster, the rats were subjected to AMPH treatment 12 h prior to the OVA airway challenge. In rats treated with AMPH, the OVA challenge reduced cell recruitment into the lung, the vascular permeability and the cellular expression of ICAM-1 and Mac-1. Additionally, elevated levels of IL-10 and IL-4 were found in samples of lung explants from allergic rats. AMPH treatment, in comparison, increased IL-10 levels but reduced those of IL-4 in the lung explants. Moreover, the tracheal responsiveness to methacholine (MCh), as well as to an in vitro OVA challenge, was reduced by AMPH treatment, and levels of PCA titers were not modified by the drug. Our findings suggest that single AMPH treatment down-regulates several parameters of lung inflammation, such as cellular migration, vascular permeability and tracheal responsiveness. These results also indicate that AMPH actions on allergic lung inflammation include endothelium-leukocyte interaction mechanisms, cytokine release and mast cell degranulation. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

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Objectives We sought to determine whether the quantitative assessment of myocardial fibrosis (MF), either by histopathology or by contrast-enhanced magnetic resonance imaging (ce-MRI), could help predict long-term survival after aortic valve replacement. Background Severe aortic valve disease is characterized by progressive accumulation of interstitial MF. Methods Fifty-four patients scheduled to undergo aortic valve replacement were examined by ce-MRI. Delayed-enhanced images were used for the quantitative assessment of MF. In addition, interstitial MF was quantified by histological analysis of myocardial samples obtained during open-heart surgery and stained with picrosirius red. The ce-MRI study was repeated 27 +/- 22 months after surgery to assess left ventricular functional improvement, and all patients were followed for 52 +/- 17 months to evaluate long-term survival. Results There was a good correlation between the amount of MF measured by histopathology and by ce-MRI (r = 0.69, p < 0.001). In addition, the amount of MF demonstrated a significant inverse correlation with the degree of left ventricular functional improvement after surgery (r = -0.42, p = 0.04 for histopathology; r = -0.47, p = 0.02 for ce-MRI). Kaplan-Meier analyses revealed that higher degrees of MF accumulation were associated with worse long-term survival (chi-square = 6.32, p = 0.01 for histopathology; chi-square = 5.85, p = 0.02 for ce-MRI). On multivariate Cox regression analyses, patient age and the amount of MF were found to be independent predictors of all-cause mortality. Conclusions The amount of MF, either by histopathology or by ce-MRI, is associated with the degree of left ventricular functional improvement and all-cause mortality late after aortic valve replacement in patients with severe aortic valve disease. (J Am Coll Cardiol 2010; 56: 278-87) (c) 2010 by the American College of Cardiology Foundation

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The effects of prolonged recruitment manoeuvre (PRM) were compared with sustained inflation (SI) in paraquat-induced mild acute lung injury (ALI) in rats. Twenty-four hours after ALI induction, rats were anesthetized and mechanically ventilated with VT = 6 ml/kg and positive end-expiratory pressure (PEEP) = 5 cmH(2)O for 1 h. SI was performed with an instantaneous pressure increase of 40 cmH(2)O that was sustained for 40 s, while PRM was done by a step-wise increase in positive inspiratory pressure (PIP) of 15-20-25 cmH(2)O above a PEEP of 15 cm H(2)O (maximal PIP = 40 cmH(2)O), with interposed periods of PIP = 10 cmH(2)O above a PEEP = 15 cmH(2)O. Lung static elastance and the amount of alveolar collapse were more reduced with PRM than SI, yielding improved oxygenation. Additionally, tumour necrosis factor-alpha, interleukin-6, interferon-gamma, and type III procollagen mRNA expressions in lung tissue and lung epithelial cell apoptosis decreased more in PRM. In conclusion, PRM improved lung function, with less damage to alveolar epithelium, resulting in reduced pulmonary injury. (C) 2009 Elsevier BLV. All rights reserved.