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Showing result 1 - 5 of 120 swedish dissertations matching the above criteria.

  1. 1. Resource efficient automatic segmentation of medical images

    Author : Minh Hoang Vu; Tommy Löfstedt; Tufve Nyholm; Anders Garpebring; Joakim Jonsson; Örjan Smedby; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; radiotherapy; medical imaging; deep learning; convolutional neural network; generative adversarial network; data augmentation; semantic segmentation; classification; activation map compression; radiofysik; radiation physics;

    Abstract : Cancer is one of the leading causes of death worldwide. In 2020, there were around 10 million cancer deaths and nearly 20 million new cancer cases in the world. Radiation therapy is essential in cancer treatments because half of the cancer patients receive radiation therapy at some point. READ MORE

  2. 2. The microdosimetric variance-covariance method used for beam quality characterization in radiation protection and radiation therapy

    Author : Jan Erik Lillhök; Lennart Lindborg; Bernd Grosswendt; Stockholms universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; ionizing radiation; radiation quality; radiation protection; radiation therapy; microdosimetry; nanodosimetry; variance-covariance method; Radiological physics; Radiofysik; medicinsk strålningsfysik; Medical Radiation Physics;

    Abstract : Radiation quality is described by the RBE (relative biological effectiveness) that varies with the ionizing ability of the radiation. Microdosimetric quantities describe distributions of energy imparted to small volumes and can be related to RBE. READ MORE

  3. 3. Quality assurance for magnetic resonance imaging (MRI) in radiotherapy

    Author : Mary Adjeiwaah; Tufve Nyholm; Rob HN Tijssen; Umeå universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnetic resonance imaging; Radiotherapy; geometric distortions; patient-induced susceptibilities MR-only; radiofysik; radiation physics;

    Abstract : Magnetic resonance imaging (MRI) utilizes the magnetic properties of tissues to generate image-forming signals. MRI has exquisite soft-tissue contrast and since tumors are mainly soft-tissues, it offers improved delineation of the target volume and nearby organs at risk. READ MORE

  4. 4. Spectral Mammography with X-Ray Optics and a Photon-Counting Detector

    Author : Erik Fredenberg; Mats Danielsson; Björn Cederström; Jeffrey H. Siewerdsen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; mammography; x-ray optics; photon counting; spectral shaping; spectral imaging; collimation; radiation dose; signal-to-noise ratio; quantum noise; anatomical noise; spatial resolution; x-ray flux; ; TECHNOLOGY; TEKNIKVETENSKAP; Engineering physics; Teknisk fysik; Optical physics; Optisk fysik; Other engineering physics; Övrig teknisk fysik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik; Medical engineering; Medicinsk teknik; Radiological research; Radiologisk forskning;

    Abstract : Early detection is vital to successfully treating breast cancer, and mammography screening is the most efficient and wide-spread method to reach this goal. Imaging low-contrast targets, while minimizing the radiation exposure to a large population is, however, a major challenge. READ MORE

  5. 5. Energy and intensity modulated radiation therapy with electrons

    Author : Lennart Olofsson; Mikael Karlsson; Magnus Karlsson; Björn Zackrisson; Erik Traneus; Umeå universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Radiation sciences; Radiation therapy; Conformal therapy; IMRT; Electrons; Electron treatment head; Electron MLC; Bremsstrahlung reduction; Integral dose; Penumbra; Output factor; Strålningsvetenskap; Radiation biology; Strålningsbiologi; radiofysik; radiation physics;

    Abstract : In recent years intensity modulated radiation therapy with photons (xIMRT) has gained attention due to its ability to reduce the dose in the tissues close to the tumour volume. However, this technique also results in a large low dose volume. READ MORE