Search for dissertations about: "computed tomography physics"

Showing result 1 - 5 of 35 swedish dissertations containing the words computed tomography physics.

  1. 1. Spectral Computed Tomography with a Photon-Counting Silicon-Strip Detector

    Author : Mats Persson; Mats Danielsson; Hans Bornefalk; Jiang Hsieh; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; Photon-counting; silicon-strip detector; spectral computed tomography; ring artifacts; fluence rate; basis material decomposition; sub-pixel information; Fysik; Physics;

    Abstract : Computed tomography (CT) is a widely used medical imaging modality. By rotating an x-ray tube and an x-ray detector around the patient, a CT scanner is able to measure the x-ray transmission from all directions and form an image of the patient’s interior. READ MORE

  2. 2. Spectral Photon-Counting Computed Tomography with Silicon Detectors: New Models and Applications

    Author : Fredrik Grönberg; Mats Danielsson; Mats Persson; Amir Pourmorteza; KTH; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; photon-counting; spectral computed tomography; material decomposition; pulse pileup; Compton scatter; image formation; fotonräknande; spektral datortomografi; materialbasupdelning; pulsöverlagring; Comptonspridning; bildbildning; Physics; Fysik;

    Abstract : X-ray computed tomography (CT) is a widely used imaging modality that enables visualization of nearly every part of the human body. It is used for diagnosis of disease and injury as well as medical treatment planning. READ MORE

  3. 3. Improvements of SPECT by a new collimator design and simultaneous transmission-emission tomography

    Author : Shahrokh Kimiaei; Marija Ivanovic; Stockholms universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Gamma camera; SPECT; Emission tomography; Transmission tomography; Planar-concave collimators; Spatial resolution; Other physics; Övrig fysik; medicinsk strålningsfysik; Medical Radiation Physics;

    Abstract : SPECT (Single Photon Emission Computed Tomography) and planar scintigraphy are the most established and world wide-spread nuclear medicine imaging techniques for clinical use today. SPECT is a tomographic technique that allows 3-D visualization of biochemical processes or physiological flow in the human body by external detection of photons from an administered radiopharmaceutical. READ MORE

  4. 4. Are gadolinium contrast media really less nephrotoxic than iodine agents in radiographic examinations? A comparison in relation to their ability to attenuate x-rays in a pig model

    Author : Barbara Elmståhl; Malmö Diagnostisk radiologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Angiography; Computed tomography; toxicity; Contrast media; Glomerular filtration; Gadolinium; Iodine; Kidney failure; Nephrotoxicity.; Medicin människa och djur ; radiology; Clinical physics; Medicine human and vertebrates ; tomography; medical instrumentation; Diagnostik; Diagnostics; medicinsk instrumentering; tomografi; radiologi; Klinisk fysiologi;

    Abstract : Purpose: To confront the statement that gadolinium contrast media (Gd-CM) are less nephrotoxic than iodine contrast media (I-CM) when used in x-ray angiographic and computed tomographic (CT) examinations. Methods: I) For CT measurements (mean density in Hounsfield numbers) 20-mL syringes filled with I- and Gd-CM at 0.01, 0.02, 0. READ MORE

  5. 5. An Event-Reconstructing Silicon Detector for 1 µm Resolution Spectral Computed Tomography

    Author : Christel Sundberg; Mats Danielsson; Julia Herzen; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photon-counting; silicon detector; spectral computed tomography; subpixel resolution; dose efficiency; coincidence tracking; event reconstruction; fotonräknande; kiseldetektor; spektral datortomografi; subpixelupplösning; doseffektivitet; koincidensspårning; händelserekonstruktion; Fysik; Physics;

    Abstract : Computed tomography (CT) is a medical imaging modality in which cross-sectional images of the human body are created using x-rays. Commercial CT scanners utilize energy-integrating detectors to measure the x-ray attenuation. However, photon-counting detectors with energy-discriminating abilities have started to emerge. READ MORE