Sökning: "Spektral CT"

Visar resultat 1 - 5 av 6 uppsatser innehållade orden Spektral CT.

  1. 1. Improving proton therapy planning with photon-counting spectral computed tomography

    Master-uppsats, KTH/Fysik

    Författare :Karin Larsson; [2023]
    Nyckelord :Proton therapy; Medical imaging; Computed Tomography; Protonterapi; Medicinsk avbildning; Datortomografi;

    Sammanfattning : Proton radiation therapy is an alternative to conventional photon radiation therapy, which accounts for the majority of radiation treatments today. The rationale for using protons in radiation therapy lies in their dose deposition properties; photons deposit a radiation dose inversely proportional to the energy, and therefore tissue depth, while protons exhibit a sharp Bragg peak when traversing matter. LÄS MER

  3. 2. Deep Ring Artifact Reduction in Photon-Counting CT

    Master-uppsats, KTH/Fysik

    Författare :Konstantinos Liappis; [2022]
    Nyckelord :Photon¬counting; Spectral CT; Material Decomposition; Deep learning; Resnet; Ring artifact; Sinogram; Fotonräknande; Spektral datortomografi; Materialdekomposition; Djupinlärning; Resnet; Ringartefakt; Sinogram;

    Sammanfattning : Ring artifacts are a common problem with the use of photon-counting detectors and commercial deployment rests on being able to compensate for them. Deep learning has been proposed as a candidate for tackling the inefficiency or high cost of traditional techniques. LÄS MER

  4. 3. Neural Networks for Material Decomposition in Photon-Counting Spectral CT

    Uppsats för yrkesexamina på avancerad nivå, KTH/Medicinteknik och hälsosystem

    Författare :Hugo Charrier; [2022]
    Nyckelord :PCCT; X-ray; scanner; photon counting; AI; neural networks;

    Sammanfattning : Photon counting computed tomography scanners constitute a major improvement of the field of computed tomography, opening various prospective and enabling the decomposition of computed tomography images into different materials. The material decomposition algorithm, mapping photon counts to material pathlengths, relies on a forward model with Poisson statistics. LÄS MER

  5. 4. Djupinlärning på sinogram för bildrekonstruktion från spektral CT

    Kandidat-uppsats, KTH/Skolan för teknikvetenskap (SCI)

    Författare :Adam Ågren; Dennis Åkerström; [2021]
    Nyckelord :;

    Sammanfattning : I takt med den nya utvecklingen av fotonräknande datortomografi med möjligheter till lägre stråldoser kommer även krav på bättre metoder för brusreducering och bildrekonstruktion. För att lösa detta problem föreslås appliceringen av ett neuralt nätverk för att filtrera bort brus och rekonstruera bilderna. LÄS MER

  7. 5. Learning the Forward Operator in Photon-Counting Computed Tomography

    Master-uppsats, KTH/Matematik (Avd.)

    Författare :Emanuel Ström; [2021]
    Nyckelord :Photon-Counting; Computed Tomography; Spectral CT; Regularisation; Deep Learning; Fotonräknande; Datortomografi; Spektral CT; Regularisering; Djupinlärning;

    Sammanfattning : Computed Tomography (CT) is a non-invasive x-ray imaging method capable of reconstructing highly detailed cross-sectional interior maps of an object. CT is used in a range of medical applications such as detection of skeletal fractures, organ trauma and artery calcification. LÄS MER