Sökning: "datortomografi fysik"

Visar resultat 1 - 5 av 10 uppsatser innehållade orden datortomografi fysik.

  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. Imaging of the MTP joint: Developing an imaging protocol optimised for damage detection and 3D modelling

    Master-uppsats, KTH/Fysik

    Författare :Johanna Jacobsson; [2022]
    Nyckelord :computed tomography; magnetic resonance imaging; cone beam computedtomography; cartilage; osteochondral lesions; metatarsal phalangeal joint; datortomografi; magnetisk resonanstomografi; kon-datortomografi; brosk; kondrala skador; metatarsalphalangen-leden;

    Sammanfattning : Walking without pain in the toe has a significant impact on a person’s well-being. Human mobility will be impaired in osteoarthritis of the big toe, and pain will occur during walking. By replacing the cartilage or bone injury with an individualised implant, osteochondral injuries to the knee and ankle can be treated. LÄS MER

  5. 4. Phase-Contrast Imaging, Towards G2-less Grating Interferometry With Deep Silicon

    Master-uppsats, KTH/Fysik

    Författare :Rickard Brunskog; [2022]
    Nyckelord :Phase-contrast imaging; phase-contrast; CT-scanning; Computed-tomography; 1 micrometer resolution x-ray; grating-less phase-contrast imaging; Faskontraströntgen; faskontrast; CT-skanning; 1 mikrometer upplösning x-ray; gitterlös faskontrast; datortomografi;

    Sammanfattning : Conventional phase-contrast imaging entails stepping an analyser grating across the detector to resolve the interference pattern caused by the x-rays after passing through a series of gratings in a so-called Talbot-Lau interferometer. However, the analyser grating in the interferometer poses a challenge, not only due to the machinery and alignment required but also due to each exposure delivering a dose to the subject. LÄS MER

  7. 5. 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