Sökning: "attenuation"

Visar resultat 16 - 20 av 408 avhandlingar innehållade ordet attenuation.

1. 16. FRC in acute lung injury. Experimental and clinical studies

   Författare :Christian Rylander; Göteborgs universitet; []
   Nyckelord :Airway obstruction; Acute lung injury; Acute respiratory distress syndrome; Attenuation; Computed tomography; End-expiratory lung volume; Functional residual capacity; Gas dilution; Hounsfield unit; Lung volume; Oleic acid; Recruitment; Time constant;

   Sammanfattning : Respiratory failure due to acute lung injury (ALI) of diffuse inflammatory origin is a major cause of respiratory failure treated in intensive care units. In ALI, FRC is reduced by various mechanisms associated with hypoxemia and consolidation of the lung. LÄS MER

3. 17. On Health-Related Quality of Life and Diagnostic Improvements in Rhinosinusitis

   Författare :Pernilla Sahlstrand Johnson; allergi och livskvalitet Laryngoesofagologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; rhinosinusitis; nasal polyps; health-related quality of life; absenteeism; Doppler ultrasound; acoustic streaming; attenuation;

   Sammanfattning : Rhinosinusitis is defined as an inflammatory process involving the mucosa of the nose and one or more of the paranasal sinuses. The aims of the work presented in this thesis were to investigate the degree to which rhinosinusitis affects the health-related quality of life (HRQOL), and to determine whether the diagnosis of this condition can be improved using Doppler ultrasound. LÄS MER

4. 18. Attenuation correction in pulmonary and myocardial single photon emission computed tomography

   Författare :Helén Almquist; Lund Klinisk fysiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Klinisk fysiologi; tomography; medical instrumentation; radiology; Clinical physics; downscatter; myocardial perfustion; ventilation-perfusion ratio; radiologi; pulmonary density; pulmonary perfusion; attenuation correction; SPECT; transmission measurement; tomografi; medicinsk instrumentering;

   Sammanfattning : The objective was to develop and validate methods for single photon emission computed tomography, SPECT, allowing quantitative physiological and diagnostic studies of lung and heart. A method for correction of variable attenuation in SPECT, based on transmission measurements before administration of an isotope to the subject, was developed and evaluated. LÄS MER

5. 19. Preclinical X-ray imaging beyond attenuation contrast

   Författare :Kian Shaker; Hans Hertz; Anna Burvall; Bert Müller; KTH; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Fysik; Physics; Biological and Biomedical Physics; Biologisk och biomedicinsk fysik;

   Sammanfattning : Medical imaging is a cornerstone of modern clinical practice. Here, X-ray imaging is the given choice for rapid morphological imaging with excellent spatial resolution, albeit with sensitivity often insufficient for resolving subtle pathological changes to soft tissues. LÄS MER

7. 20. Attenuation of the behavioural effects of alcohol : antagonism and acute tolerance

   Författare :Arto J. Hiltunen; Uppsala universitet; []
   Nyckelord :SOCIAL SCIENCES; SAMHÄLLSVETENSKAP;

   Sammanfattning : .... LÄS MER