Sökning: "physics"

Visar resultat 1 - 5 av 2217 uppsatser innehållade ordet physics.

  1. 1. osimetric impact of system spe cific geometric distortion on head and neck treatment plans in MRI only based radiation therapy

    Master-uppsats,

    Författare :Jesper Brovall; [2022-01-13]
    Nyckelord :Medical physics; Dosimetry; MRI; Radiation therapy;

    Sammanfattning : Background/ purpose: Because of the superior soft tissue contrast, in comparison with computed tomography (CT) data, magnetic resonance imaging (MRI) is of high interest to include in a larger extent in the ra diation therapy (RT) process. In an MRI only workflow, the CT scan is excluded and a synthetic CT is used for treatment plan ning. LÄS MER

  2. 2. ESTIMATION OF RADIATION EXPOSURE FROM NATURALLY OCCURRING RADIONUCLIDES IN FOOD AND FOODSTUFF

    Master-uppsats,

    Författare :Ida Bengtsson; [2022-01-13]
    Nyckelord :Medical physics; Naturally occurring radionuclides; committed effective dose from ingested radionuclides; Biokinetic models;

    Sammanfattning : Purpose: The main purpose of this study was to provide an estimation of the committed effective dose received by the Swedish population from naturally occurring radionuclides (NORM) in the diet. This study was also aiming to investigate the impact on the committed effective dose due to the new developments in the biokinetic model for Po 210 . LÄS MER

  3. 3. ATLAS-BASED SEGMENTATION OF ULTRAHIGH-RESOLUTION STRUCTURAL MR HEAD IMAGES ACQUIRED AT 7 TESLA

    Master-uppsats,

    Författare :Frida Johansson; [2022-01-13]
    Nyckelord :Medical physics; Anatomical segmentation; Brain; MRI; 7 Tesla; Pincram; MAPER; Shape based averaging; Ultrahigh resolution;

    Sammanfattning : Purpose: The purpose of this work was to find out how the existing brain atlases and segmentation algorithms perform when applied to ultrahigh-resolution MR brain images, acquired with a 7-Tesla scanner. Also to make adaptations to deal with the potential challenges and evaluate the quality of the anatomical segmentations of the 7- Tesla images. LÄS MER

  4. 4. Evaluation of whole-body bone scans performed using a gamma camera with Cadmium Zinc Telluride detector

    Master-uppsats,

    Författare :Victor Asp; [2022-01-13]
    Nyckelord :Medical physics; whole-body bone scans; gamma camera; Cadmium Zinc Telluride detector;

    Sammanfattning : The bone scan is a common nuclear medicine imaging procedure that is mainly used for evaluating several oncological patient groups. A radioactive tracer, 99mTc -labelled diphosphonate, is injected intravenously and accumulates in the skeleton. The distribution of the tracer in the body is measured with a gamma camera 3 hours post-injection. LÄS MER

  5. 5. STANDARDIZED ORGAN AT RISK VOLUME FOR EXTERNAL BEAM RADIATION THERAPY IN PROSTATE CANCER AND ITS RELATIONSHIP TO VOLUMES DEFINED BY CLINICAL PRACTICE

    Master-uppsats,

    Författare :Dang Thao; [2022-01-13]
    Nyckelord :Medical physics; Radiation therapy; Prostate cancer; Organs at risk;

    Sammanfattning : Background/ Purpose: In radiation therapy (RT), the radiation dose calculated in tumours and normal tissue depends on how the volumes are defined. It is difficult to standardize how tumour volumes should be defined because their anatomical extension can differ greatly between individuals. LÄS MER