Sökning: "mr fysik"

Visar resultat 1 - 5 av 23 uppsatser innehållade orden mr fysik.

  1. 1. Evaluation of a Novel Reconstruction Framework for Gamma Knife Cone-Beam CT - The Impact of Scatter Correction and Noise Filtering on Image Quality and Co-registration Accuracy

    Master-uppsats, KTH/Fysik

    Författare :Ida Hägnestrand; [2023]
    Nyckelord :Gamma Knife; Cone-beam computed tomography; Image quality; Image reconstruction; Co-registration; Contrast; Uniformity; Spatial resolution; Scatter correction; Wiener filter; Noise filter; Patient positioning; Stereotactic radiosurgery; Gammakniv; Strålkniv; Cone-Beam Computed Tomography; Bildkvalitet; Bildrekonstruktion; Co-registrering; Kontrast; Uniformitet; Spatial upplösning; Spridningskorrigering; Wienerfilter; Brusfilter; Stereotaktisk strålkirurgi;

    Sammanfattning : The Gamma Knife is a non-invasive stereotactic radiosurgery system used for treatments of deep targets in the brain. Accurate patient positioning is needed for precise radiation delivery to the target. LÄS MER

  3. 2. Generating Synthetic CT Images Using Diffusion Models

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Salih Saleh; [2023]
    Nyckelord :Machine learning; artificial intelligence; generative models; diffusion models; MRI; CT; synthetic CT; radiation therapy;

    Sammanfattning : Magnetic resonance (MR) images together with computed tomography (CT) images are used in many medical practices, such as radiation therapy. To capture those images, patients have to undergo two separate scans: one for the MR image, which involves using strong magnetic fields, and one for the CT image which involves using radiation (x-rays). LÄS MER

  4. 3. Impact of MR training data on the quality of synthetic CT generation

    Uppsats för yrkesexamina på avancerad nivå, Umeå universitet/Institutionen för fysik

    Författare :Gustav Jönsson; [2022]
    Nyckelord :Generative adversarial network; Machine learning; Radiotherapy; Synthetic CT; MR; CT;

    Sammanfattning : Both computed tomography (CT) and magnetic resonance imaging (MRI) have a purpose for radiotherapy. But having two imaging sessions brings uncertainty which makes it beneficial to create synthetic CT (sCT) images from MR images. In this work a Generative Adversarial Network (GAN) was designed and implemented for sCT generation. LÄS MER

  5. 4. Verification measurements on MRI-linac with PTW BEAMSCAN MR

    Master-uppsats, Umeå universitet/Institutionen för fysik

    Författare :Olivia Kvarnlöf; [2022]
    Nyckelord :;

    Sammanfattning : In radiotherapy the main goal is to kill cancer cells, prevent them from growing and reproducing, while healthy tissue is spared. One technique to treat cancer is to use external radiotherapy where a linear accelerator (linac) is used to generate a high energy radiation photon beam. LÄS MER

  7. 5. Correlation between PET/MRI image features andpathological subtypes for localized prostate cancer

    Master-uppsats, Umeå universitet/Institutionen för fysik

    Författare :Jens Lindahl; [2021]
    Nyckelord :MRI; PET; Image features; Image processing; Localized prostate cancer; Pathological subtypes; MR; PET; Bildegenskaper; Bildbehandling; Lokal prostata cancer; Patologiska undertyper;

    Sammanfattning : Prostate cancer is the most common cancer in Sweden. Patients with the condition have a good prognosis in general and most cases can be treated. LÄS MER