Sökning: "Medical physics"

Visar resultat 1 - 5 av 66 uppsatser innehållade orden Medical physics.

  1. 1. COMPARISON OF MULTI-CRITERIA OPTIMIZATION IN TWO DIFFERENT TREATMENT PLANNING SYSTEMS

    Master-uppsats,

    Författare :Anna Lindström; [2021-05-10]
    Nyckelord :Medical physics; Multi-criteria optimization; Pareto front; volumetric modulated arc therapy; head and neck cancer; prostate cancer;

    Sammanfattning : Purpose: The purpose with this study was to compare multi-criteria optimization (MCO) for volumetric modulated arc therapy (VMAT) treatment plans in two different treatment planning systems. Theory: When performing treatment planning prior to radiation therapy it is important to prioritize between absorbed dose to target and absorbed dose to organs at risk (OAR). LÄS MER

  2. 2. DEFORMABLE IMAGE REGISTRATION OF SPINE MAGNETIC RESONANCE IMAGES WITH ELASTIX FOR DETAILED CHARACTERIZATION OF DISC LOADING BEHAVIORS

    Master-uppsats,

    Författare :Zainab Sirat; [2021-05-10]
    Nyckelord :Medical physics; Registration; MRI; Spine;

    Sammanfattning : Purpose: This work aimed to develop an optimized strategy for registration of spine magnetic resonance (MR) images acquired with and without spinal loading, as well as evaluate the quality of the registration strategy with commonly used quality assessment methods. Method: Previously collected MR images of the lumbar spine of 37 individuals were re analyzed. LÄS MER

  3. 3. The value of cardiac MRI texture analysis in patients with clinically suspected myocarditis

    Master-uppsats,

    Författare :Evin Ina Papalini; [2021-05-10]
    Nyckelord :Medical physics; Myocarditis; Cardiac magnetic resonance; Texture analysis;

    Sammanfattning : Purpose: The aim of this proof-of-concept study was to assess the diagnostic value of texture analysis (TA) based on conventional balanced steady-state-free precession (bSSFP), late gadolinium enhancement (LGE) and T2-weighted cardiac magnetic resonance imaging (CMRI) in patients with clinically suspected myocarditis.Method: A retrospective cohort study was performed based on 30 patients whounderwent a comprehensive CMRI due to clinically suspected myocarditisbetween 2013 and 2018 at the Sahlgrenska University Hospital: 10 patients with clinical signs and positive myocardial biomarkers (Troponin T, indicating myocardial injury) as well as positive CMRI findings according to Lake Louise Criteria (LLC; group 1), 10 patients with clinical signs and positive myocardial biomarkers but negative CMRI findings according to LLC (group 2), and 10 patients with clinical signs but both negative myocardial biomarkers as well as CMRI findings according to LLC (control group). LÄS MER

  4. 4. Characterization of discrepancies between manual and automatic segmentation to improve anatomical brain atlases

    Master-uppsats,

    Författare :Anna Sörensson; [2021-05-10]
    Nyckelord :Medical physics; Anatomical brain atlas; Image segmentation; Image registration;

    Sammanfattning : Purpose: To characterize discrepancies between expert manually segmented brain images fromHammers Atlas Database and automatically generated segmentations of the same images; to decide whether they can be attributed to flaws in the automatic segmentation or in the manual segmentation; and to determine general rules that enable these decisions.Theory: Image segmentation plays an important role in clinical neuroscience and experimental medicine for extraction of information from medical images, and it is a fundamental image processing step in medical image analysis. LÄS MER

  5. 5. DEVELOPMENT, VALIDATION AND APPLICATION OF A METHOD FOR DETERMINATION OF METABOLITE CONCENTRATIONS WITH PRECLINICAL MAGNETIC RESONANCE SPECTROSCOPY

    Master-uppsats,

    Författare :Lukas Lundholm; [2021-05-10]
    Nyckelord :Medical physics; Basis sets; Metabolites; Quantification; Animal study; MRS;

    Sammanfattning : Background: Information on the metabolic content in tissue has diagnostic and prognostic value when examining for example cancer and diseases of the brain. MR spectroscopy is a non-invasive method that allows quantification of metabolite concentrations in vivo, without the use of ionizing radiation, which makes the method highly attractive for both research and clinical applications. LÄS MER