Sökning: "geometric distortions"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden geometric distortions.

  1. 1. Geometric distortions in MRI based radiotherapy and PET/MRI

    Författare :Josef Lundman; Tufve Nyholm; Anne Larsson; Jörgen Olofsson; Marco Riboldi; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Magnetic resonance imaging; MRI; PET MR; PET MRI; medical imaging; radiotherapy; geometrical distortions; MR-only; MRI-only; radiofysik; radiation physics;

    Sammanfattning : Magnetic resonance imaging (MRI) offers high soft-tissue contrast compared to computed tomography (CT). This contrast is helpful in many cases, not least for delineating tumours for radiotherapy treatment, and has led to increasing use in radiotherapy treatment planning (RTP). LÄS MER

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

    Författare :Mary Adjeiwaah; Tufve Nyholm; Rob HN Tijssen; Umeå universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

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

    Författare :Mary Adjeiwaah; Tufve Nyholm; Anders Garpebring; Joakim Jonsson; Sofie Ceberg; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; magnetic resonance imaging; MRI; radiotherapy; RT; geometric distortions; magnetic susceptibility; B0 maps; quality assurance; radiofysik; radiation physics;

    Sammanfattning : The use of Magnetic Resonance Imaging (MRI) in the radiotherapy (RT) treatment planning workflow is increasing. MRI offers superior soft-tissue contrast compared to Computed Tomography (CT) and therefore improves the accuracy in target volume definitions. LÄS MER

  5. 4. Geometric Models for Rolling-shutter and Push-broom Sensors

    Författare :Erik Ringaby; Per-Erik Forssén; Tomáŝ Pajdla; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Almost all cell-phones and camcorders sold today are equipped with a  CMOS (Complementary Metal Oxide Semiconductor) image sensor and there is also a general trend to incorporate CMOS sensors in other types of cameras. The CMOS sensor has many advantages over the more conventional CCD (Charge-Coupled Device) sensor such as lower power consumption, cheaper manufacturing and the potential for onchip processing. LÄS MER

  7. 5. Geometric Computer Vision for Rolling-shutter and Push-broom Sensors

    Författare :Erik Ringaby; Per-Erik Forssén; Anders Heyden; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rolling shutter cmos video rectification stabilisation push-broom kinect;

    Sammanfattning : Almost all cell-phones and camcorders sold today are equipped with a CMOS (Complementary Metal Oxide Semiconductor) image sensor and there is also a general trend to incorporate CMOS sensors in other types of cameras. The sensor has many advantages over the more conventional CCD (Charge-Coupled Device) sensor such as lower power consumption, cheaper manufacturing and the potential for on-chip processing. LÄS MER