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排序方式: 共有1501条查询结果,搜索用时 31 毫秒
71.
Low-dose CT of the paranasal sinuses with eye lens protection: effect on image quality and radiation dose 总被引:10,自引:2,他引:8
The purpose of the study was to assess the effect of lens protection on image quality and radiation dose to the eye lenses in CT of the paranasal sinuses. In 127 patients referred to rule out sinusitis, an axial spiral CT with a lens protection placed on the patients eyes was obtained (1.5/2/1, 50 mAs, 120 kV). Coronal views were reconstructed at 5-mm interval. To quantify a subjective impression of image quality, three regions of interest within the eyeball were plotted along a line perpendicular to the protection at 2, 5, and 9 mm beneath skin level on the axial images. Additionally, dose reduction of a bismuth-containing latex shield was measured using a film-dosimetry technique. The average eyeball density was 17.97 HU (SD 3.7 HU). The relative increase in CT density was 180.6 (17.7), 103.3 (11.7), and 53.6 HU (9.2), respectively. There was no diagnostic information loss on axial and coronal views observed. Artifacts were practically invisible on images viewed in a bone window/level setting. The use of the shield reduced skin radiation from 7.5 to 4.5 mGy. The utilization of a radioprotection to the eye lenses in paranasal CT is a suitable and effective means of reducing skin radiation by 40%. 相似文献
72.
73.
Studies of hemispatial neglect suggest that some perceptual processes still operate on contralesional stimuli independent from spatial attention or awareness. Here we examined whether preattentive processing in extrastriate areas may group unconnected elements inducing illusory contours despite neglect. While it has been debated whether illusory contours arise from preattentive grouping or higher cognitive processes, neurophysiological studies show that neurones in secondary visual cortex (V2) can code for illusory contours. Twelve patients with right hemisphere damage and left neglect were tested for implicit and explicit detection of illusory contours using, respectively: (1) a bisection task where patients were not explicitly required to attend to lateral elements and judged the midpoint of Kanizsa illusory stimuli, as well as other physically connected or unconnected stimuli of the same length; (2) a matching task where patients had to overtly attend to lateral elements and made same/different judgements on pairs of illusory stimuli with identical or different inducers on the right or left side. In some patients, bisection judgements were consistently similar on Kanizsa stimuli with illusory contours and connected stimuli with real contours but different on unconnected gap figures, regardless of their length, suggesting implicit grouping of inducing elements prior to processing stages where a spatial attentional bias arose. Their lesions centred on the inferior parietal cortex or thalamus. Other patients did not show a systematic bisection pattern and had lesions extending posteriorly in the lateral occipital cortex. However, both groups of patients failed to detect left-side inducers in explicit matching judgements, even though errors often revealed unconscious processing, and they showed similar neglect severity on other standard tests. These findings suggest that grouping by illusory contours can occur preattentively and influence bisection independently from the ability to detect contralateral inducers explicitly, severity of inattention, and other forms of unconscious processing. Implicit grouping may depend on the sparing of lateral occipital areas involved in figure-ground segmentation at early stages of visual processing. 相似文献
74.
Peloponissios N Halkic N Moeschler O Schnyder P Vuilleumier H 《The Annals of thoracic surgery》2001,71(3):1019-1021
Arrow wounds are very rare. We present herein a case of hilar penetrating thoracic trauma caused by an arrow, and a review of the literature, to clarify the management of these cases and their indications for surgery. Depending on the type of arrowhead, the tissue elasticity can narrow the wound track around the shaft of the arrow, sometimes causing a tamponade effect. In the mediastinal or hilar area, an arrow should not be removed before an injury to the major blood vessels or the heart has been ruled out. 相似文献
75.
Gisela Kobelt PhD Patrik Sobocki PhD Juan Mulero MD Jordi Gratacos MD Ana Pocovi MS Eduardo Collantes-Estevez MD 《Value in health》2008,11(3):408-415
Objective: To investigate the burden of ankylosing spondylitis (AS) in Spain, as baseline for economic evaluation of the use of biological agents.
Methods: A cross-sectional retrospective observational study was performed in 601 patients with AS in Spain, using a methodology developed in studies in the United Kingdom and Canada. Patients were mailed a questionnaire asking about their health-care consumption, out-of-pocket expenses, work capacity, need for informal care during the past 3 months, as well as quality of life. Patient's current functional status and disease activity level was assessed using the Bath functional and disease activity indexes (BASFI and BASDAI).
Results: The mean age (median) was 47.8 (12.4) years, and the mean disease duration was 18.8 years. Eighty percent of patients were male, and slightly more than half of patients below 65 years of age were working. The mean (median) BASDAI and BASFI scores were 4.3 (2.5) and 3.8 (2.9),respectively, and all levels of disease severity were represented. The mean (median) total annual cost per patient is estimated at €20,328 (€7920). Direct health care represented 22.8%, investments (adaptations of house and devices) and informal care 43.5%, and productivity losses 33.7%. Costs increased significantly with worsening disease, in particular diminishing physical function, covering a range between €5000 and €75,000 per patient and year. The mean (median) utility was 0.59 (0.30). Utility showed a significant inverse relation with BASFI and BASDAI, covering a range from 0.80 for patients with BASFI/BASDAI below 3 to 0.25 for patients with BASFI/BASDAI greater than 7.
Conclusions: As in studies in other countries, all types of costs accelerate steeply with worsening disease while utility decreases significantly, indicating the need to prevent disease progression. 相似文献
Methods: A cross-sectional retrospective observational study was performed in 601 patients with AS in Spain, using a methodology developed in studies in the United Kingdom and Canada. Patients were mailed a questionnaire asking about their health-care consumption, out-of-pocket expenses, work capacity, need for informal care during the past 3 months, as well as quality of life. Patient's current functional status and disease activity level was assessed using the Bath functional and disease activity indexes (BASFI and BASDAI).
Results: The mean age (median) was 47.8 (12.4) years, and the mean disease duration was 18.8 years. Eighty percent of patients were male, and slightly more than half of patients below 65 years of age were working. The mean (median) BASDAI and BASFI scores were 4.3 (2.5) and 3.8 (2.9),respectively, and all levels of disease severity were represented. The mean (median) total annual cost per patient is estimated at €20,328 (€7920). Direct health care represented 22.8%, investments (adaptations of house and devices) and informal care 43.5%, and productivity losses 33.7%. Costs increased significantly with worsening disease, in particular diminishing physical function, covering a range between €5000 and €75,000 per patient and year. The mean (median) utility was 0.59 (0.30). Utility showed a significant inverse relation with BASFI and BASDAI, covering a range from 0.80 for patients with BASFI/BASDAI below 3 to 0.25 for patients with BASFI/BASDAI greater than 7.
Conclusions: As in studies in other countries, all types of costs accelerate steeply with worsening disease while utility decreases significantly, indicating the need to prevent disease progression. 相似文献
76.
The present stud y examines the capacity of fetal neocortical grafts placed in a brain infarct to exchange axonal projections with the host brain. Five to 7 days after a middle cerebral artery occlusion in adult spontaneously hypertensive rats, dissociated neocortical primordium from fetuses of gestational age 15-16 days was implanted into the infarcted area. Four to 11 months later, the neural tracers Phaseolus vulgaris-leucoagglutinin and Fluoro-Gold were injected in the grafts and host neocortex. An extensive axonal network was present in the transplants but only one of eight rats with appropriate placed injections displayed efferent connections from transplant to host. The sparse axonal outgrowth indicates major limitations for fetal rat cortical grafts to form connections with host neural circuitries after an ischemic insult. 相似文献
77.
78.
OBJECTIVE: To report the side-effects after a reduction in the dwell-time in patients who had pronounced symptoms after intravesical bacillus Calmette-Guèrin (BCG) treatment, as side-effects such as fever, haematuria, and frequency are common and sometimes severe after BCG treatment in patients with bladder cancer. PATIENTS AND METHODS: The dwell-time was reduced to < or = 30 min in 51 patients who had pronounced side-effects after the preceding BCG instillation. All patients self-reported side-effects after each instillation in a questionnaire. RESULTS: After reducing the BCG dwell-time, fever, chills, dysuria and the overall time-to-recovery were significantly reduced but frequency and haematuria were not influenced. Patients with carcinoma in situ had significantly less dysuria than patients with papillary tumours. There was no difference in the treatment results between patients who had a normal dwell-time and a reduced dwell-time, determined at the first and second follow-up cystoscopy. CONCLUSION: Reducing the BCG dwell-time to < or = 30 min could be an alternative to a dose reduction in patients who experience pronounced side-effects after BCG instillations. The long-term outcome after reducing dwell-time and after dose reduction has not been studied and warrants further investigation. 相似文献
79.
Francis P Fernebro J Edén P Laurell A Rydholm A Domanski HA Breslin T Hegardt C Borg A Nilbert M 《Genes, chromosomes & cancer》2005,43(3):302-308
Soft-tissue sarcomas (STSs) constitute more than 30 histologic entities. In addition, within each entity, tumors are often heterogeneous in macroscopic features, genetic alterations, microscopic appearance, and clinical course. Therefore, there has been concern about whether a single tumor sample can provide a gene expression profile representative of the entire tumor. We used 27-k cDNA microarray slides to assess the importance of intratumor versus intertumor heterogeneity of the gene expression profiles of 2 morphologically heterogeneous STSs. Multiple pieces of tumor (8 and 10 pieces) were obtained from a myxoid variant of malignant fibrous histiocytoma (MFH) and a leiomyosarcoma (LMS), respectively, and the expression patterns were compared with single tumor samples from 20 MFHs and 16 LMSs. Hierarchical clustering analysis of the expression profiles showed that samples from the same tumor clustered together. The average intratumor distance was considerably shorter than the average intertumor distance in both LMS and MFH. In addition, tumor subclusters that distinguished different macroscopic parts of the tumor could be discerned. We concluded that intratumor variability exists but that accurate gene expression profiling also could be obtained using single samples from a large STS. 相似文献
80.
Grandjean D Sander D Pourtois G Schwartz S Seghier ML Scherer KR Vuilleumier P 《Nature neuroscience》2005,8(2):145-146
We report two functional magnetic resonance imaging experiments showing enhanced responses in human middle superior temporal sulcus for angry relative to neutral prosody. This emotional enhancement was voice specific, unrelated to isolated acoustic amplitude or frequency cues in angry prosody, and distinct from any concomitant task-related attentional modulation. Attention and emotion seem to have separate effects on stimulus processing, reflecting a fundamental principle of human brain organization shared by voice and face perception. 相似文献