Sökning: "dos ct"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden dos ct.

1. 1. Image Quality Optimisation and Dose Management in CT, SPECT/CT, and PET/CT

   Författare :Marcus Söderberg; Malmö Medicinsk strålningsfysik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; CT; SPECT; PET; dosimetry; image quality; optimisation; dose reduction; automatic exposure control; contrast medium; phantom; image reconstruction; human observer;

   Sammanfattning : The significant increase in the use of CT, alone or combined with SPECT or PET, has raised concerns about patient radiation exposure and the consequent increased risk of malignancy later in life. The overall objective of this work was to evaluate and optimise different approaches for minimising patient radiation absorbed dose and maintaining or improving image quality in CT, SPECT/CT, and PET/CT. LÄS MER

3. 2. Methods of image acquisition and calibration for x-ray computed tomography

   Författare :Martin Sjölin; Mats Danielsson; J. Webster Stayman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Medical Technology; Medicinsk teknologi;

   Sammanfattning : X-ray computed tomography (CT) is a common medical imaging device for acquiring high-resolution 3D images of the interior of the human body. The images are formed by mathematical reconstruction from hundreds of planar x-ray images that have been acquired during less then a second. LÄS MER

4. 3. Visual grading evaluation of reconstruction methods and dose optimisation in abdominal Computed Tomography

   Författare :Bharti Kataria; Michael Sandborg; Örjan Smedby; Anders Persson; Hannibal Sökjer; Håkan Geijer; Linköpings universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES;

   Sammanfattning : Since its introduction in the 1970’s CT has emerged as a modality of choice because of its high sensitivity in producing accurate diagnostic images. A third of all Computed Tomography (CT) examinations are abdominal CTs which deliver one of the highest doses among common examinations. LÄS MER

5. 4. Image Processing for Quantitative Scintillation-Camera Imaging. Application to Radionuclide Therapy

   Författare :Katarina Sjögreen Gleisner; Lund Medicinsk strålningsfysik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; tomografi; radiologi; Klinisk fysiologi; medical instrumentation; tomography; radiology; 131-I; Clinical physics; SPECT; conjugate-view; volume quantification; activity quantification; image registration; image segmentation; medicinsk instrumentering; Nuclear medicine; radiobiology; Nukleärmedicin; radiobiologi; Radiopharmaceutical technology; Radiofarmaceutisk teknik;

   Sammanfattning : Individual-based determinations of the absorbed dose in radionuclide therapy largely rely on absolute measurement of the activity distribution and its redistribution over time. Scintillation-camera imaging is the most commonly employed measuring technique, applied in planar or SPECT mode, sometimes in combination with structural images from CT. LÄS MER

7. 5. Tomosynthesis in pulmonary cystic fibrosis

   Författare :Kristina Vult von Steyern; Lund Diagnostisk radiologi; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cystic fibrosis; Lung; Radiation dose; Radiography; Scoring methods; Tomography; spiral computed; X-ray computed;

   Sammanfattning : The aims of this thesis were to investigate whether chest tomosynthesis might be used in pulmonary cystic fibrosis, to design and validate a tomosynthesis scoring system, and to determine the effective dose from chest tomosynthesis in children. In a prospective study starting in 2008 clinical chest radiography or computed tomography (CT) were supplemented with a tomosynthesis examination of the lungs. LÄS MER