Sökning: "röntgenavbildning"

Visar resultat 1 - 5 av 6 uppsatser innehållade ordet röntgenavbildning.

  1. 1. Detective Quantum Efficiency in the Image Domain

    Master-uppsats, KTH/Fysik

    Författare :Per Lundhammar; [2022]
    Nyckelord :detective quantum efficiency; linear systems theory; projection domain; image domain; x-ray imaging; detektiv kvanteffektivitet; linjär-systemteori; projektionsdomän; bilddomän; röntgenavbildning;

    Sammanfattning : We investigate the signal and noise transform characteristics from the projection domain to the image domain in a linear systems theory framework and predictions of the DQE within this framework are made. A simulation study of a photon counting silicon detector is made from which the energy information is used in order to produce synthetic monoenergetic images. LÄS MER

  3. 2. High resolution x-ray imaging by measuring the induced charge distribution

    Master-uppsats, KTH/Fysik

    Författare :Zihui Jin; [2022]
    Nyckelord :Computed tomography; photon-counting detector; silicon; spatial resolution; Datortomografi; fotonräknande detektor; kisel; spatial upplösning;

    Sammanfattning : Computed tomography (CT) is a medical imaging technique used to create cross-section images of human bodies based on x-rays. The emerging photon-counting CT detector shows several advantages compared with the traditional energy integrating detector. LÄS MER

  4. 3. Karaktärisering av spatial upplösning i röntgenmikroskopi

    Kandidat-uppsats, Mittuniversitetet/Institutionen för elektronikkonstruktion

    Författare :Alia Jabar; [2021]
    Nyckelord :Spatial upplösning; fokalpunkt; Medipix3; Innocare; röntgenmikroskop; karaktärisering; elektroteknik;

    Sammanfattning : X-ray imaging was a very important detection that is used in many useful functionalities as in healthcare. It would be powerful and facilitate several functions if we could come up with a method that gives a better resolution when doing X-ray imaging. LÄS MER

  5. 4. 2D & 3D phase retrieval for propagation-based X-ray phase-contrast tomography

    Master-uppsats, Lunds universitet/Synkrotronljusfysik; Lunds universitet/Fysiska institutionen

    Författare :Philip Stjärneblad; [2021]
    Nyckelord :Propagation-based X-ray phase-contrast tomography; PB-PCT; Propagation-based X-ray phase-contrast Imaging; PB-PCI; 2d phase retrieval; 3d phase retrieval; TIE; sinogram consistency; reconstruction artefacts; Science General;

    Sammanfattning : Propagation-based X-ray phase-contrast tomography is a 3d imaging technique that utilizes two-dimensional projections from different angular views $\theta =[0,\pi]$ to reconstruct the 3D object information. The phase-contrast allows for higher feature contrast than conventional transmission tomography, as the phase interference gives rise to a sharp edge contrast. LÄS MER

  7. 5. Event-based High Resolution X-ray Imaging using Compton Coincidence Detection

    Master-uppsats, KTH/Medicinsk avbildning

    Författare :Eva Bergström; [2021]
    Nyckelord :Photon counting CT; Compton scattering; Compton kinematics; coincidence detection; χ2 test; Fotonräknande CT; Compton-spridning; Compton-kinematik; sammanfallsdetektering; χ2 -test;

    Sammanfattning : Research on photon counting detectors (PCDs) is focused on semiconductor materials, and silicon is a strong candidate to use in PCDs for photon counting computer tomography (CT). In a silicon detector, a significant portion of the counts is due to Compton scattering events. LÄS MER