Sökning: "spectral computed tomography"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden spectral computed tomography.

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

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Mats Persson; KTH.; [2016]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Photon-counting; silicon-strip detector; spectral computed tomography; ring artifacts; fluence rate; basis material decomposition; sub-pixel information; Physics; Fysik;

    Sammanfattning : 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. LÄS MER

  2. 2. A Segmented Silicon Strip Detector for Photon-Counting Spectral Computed Tomography

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Cheng Xu; KTH.; [2012]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; photon counting; spectral computed tomography; silicon strip detector; ASIC; energy resolution; cadmium telluride; charge sharing; Monte Carlo simulation; synchrotron;

    Sammanfattning : Spectral computed tomography with energy-resolving detectors has a potential to improve the detectability of images and correspondingly reduce the radiation dose to patients by extracting and properly using the energy information in the broad x-ray spectrum. A silicon photon-counting detector has been developed for spectral CT and it has successfully solved the problem of high photon flux in clinical CT applications by adopting the segmented detector structure and operating the detector in edge-on geometry. LÄS MER

  3. 3. Quantification and Maximization of Performance Measures for Photon Counting Spectral Computed Tomography

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Moa Yveborg; KTH.; [2015]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spectral computed tomography; silicon detector; detectability index; photon counting; Hotelling SDNR; material basis decomposition;

    Sammanfattning : During my time as a PhD student at the Physics of Medical Imaging group at KTH, I have taken part in the work of developing a photon counting spectrally resolved silicon detector for clinical computed tomography. This work has largely motivated the direction of my research, and is the main reason for my focus on certain issues. LÄS MER

  4. 4. Characterization and Optimization of Silicon-strip Detectors for Mammography and Computed Tomography

    Detta är en avhandling från STOCKHOLM : KTH Royal Institute of Technology

    Författare :Han Chen; KTH.; [2016]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mammography; anti-scatter grid; photon-counting; spectral computed tomography; silicon strip; ASIC; energy resolution; Compton scatter; material decomposition; K-edge imaging; Medicinsk teknologi; Medical Technology;

    Sammanfattning : The goal in medical x-ray imaging is to obtain the image quality requiredfor a given detection task, while ensuring that the patient dose is kept as lowas reasonably achievable. The two most common strategies for dose reductionare: optimizing incident x-ray beams and utilizing energy informationof transmitted beams with new detector techniques (spectral imaging). LÄS MER

  5. 5. Characterization and Energy Calibration of a Silicon-Strip Detector for Photon-Counting Spectral Computed Tomography

    Detta är en avhandling från Stockholm, Sweden : KTH Royal Institute of Technology

    Författare :Xuejin Liu; KTH.; [2016]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Medicinsk teknologi; Medical Technology;

    Sammanfattning : Multibin photon-counting x-ray detectors are promising candidates to be applied in next generation computed tomography (CT), whereby energy information from a broad x-ray spectrum can be extracted and properly used for improving image quality and correspondingly reducing radiation dose. A silicon-strip detector has been developed for spectral CT, which operates in photon-counting mode and allows pulse-height discrimination with 8 adjustable energy bins. LÄS MER