Essays about: "röntgenavbildning"

Found 5 essays containing the word röntgenavbildning.

1. 1. Detective Quantum Efficiency in the Image Domain

   University essay from KTH/Fysik

   Author : Per Lundhammar; [2022]
   Keywords : detective quantum efficiency; linear systems theory; projection domain; image domain; x-ray imaging; detektiv kvanteffektivitet; linjär-systemteori; projektionsdomän; bilddomän; röntgenavbildning;

   Abstract : We investigate the signal and noise transform characteristics from the projection domain to the image domain in a linear systems theory framework and predictions of the DQE within this framework are made. A simulation study of a photon counting silicon detector is made from which the energy information is used in order to produce synthetic monoenergetic images. READ MORE

3. 2. High resolution x-ray imaging by measuring the induced charge distribution

   University essay from KTH/Fysik

   Author : Zihui Jin; [2022]
   Keywords : Computed tomography; photon-counting detector; silicon; spatial resolution; Datortomografi; fotonräknande detektor; kisel; spatial upplösning;

   Abstract : Computed tomography (CT) is a medical imaging technique used to create cross-section images of human bodies based on x-rays. The emerging photon-counting CT detector shows several advantages compared with the traditional energy integrating detector. READ MORE

4. 3. 2D & 3D phase retrieval for propagation-based X-ray phase-contrast tomography

   University essay from Lunds universitet/Synkrotronljusfysik; Lunds universitet/Fysiska institutionen

   Author : Philip Stjärneblad; [2021]
   Keywords : Propagation-based X-ray phase-contrast tomography; PB-PCT; Propagation-based X-ray phase-contrast Imaging; PB-PCI; 2d phase retrieval; 3d phase retrieval; TIE; sinogram consistency; reconstruction artefacts; Science General;

   Abstract : Propagation-based X-ray phase-contrast tomography is a 3d imaging technique that utilizes two-dimensional projections from different angular views $\theta =[0,\pi]$ to reconstruct the 3D object information. The phase-contrast allows for higher feature contrast than conventional transmission tomography, as the phase interference gives rise to a sharp edge contrast. READ MORE

5. 4. Event-based High Resolution X-ray Imaging using Compton Coincidence Detection

   University essay from KTH/Medicinsk avbildning

   Author : Eva Bergström; [2021]
   Keywords : Photon counting CT; Compton scattering; Compton kinematics; coincidence detection; χ2 test; Fotonräknande CT; Compton-spridning; Compton-kinematik; sammanfallsdetektering; χ2 -test;

   Abstract : Research on photon counting detectors (PCDs) is focused on semiconductor materials, and silicon is a strong candidate to use in PCDs for photon counting computer tomography (CT). In a silicon detector, a significant portion of the counts is due to Compton scattering events. READ MORE

6. 5. Iterative Reconstruction Algorithm for Phase-Contrast X-Ray Imaging

   University essay from KTH/Medicinteknik och hälsosystem

   Author : Ahmad Sadek; Ruben Pozzi; [2020]
   Keywords : Computed tomography; Medical research; Phase-contrast imaging; Propagation-based imaging; SIRT; Iterative algorithm; Paganin’s phase-retrieval; Datortomografi; Medicinsk forskning; Faskontrastavbildning; Propagation-baserad avbildning; SIRT; Iterativ algoritm; Paganins fasåterhämtning;

   Abstract : Phase-contrast imaging (PCI) is a modality of medical x-ray imaging that can solve one of the main limitations with conventional attenuation-based imaging: the imaging of materials with low attenuation coefficients, such as soft tissues. A modality of PCI, Propagation-based phase-contrast imaging (PBI), was used in this project. READ MORE