Sökning: "Photon-counting detector"
Visar resultat 1 - 5 av 19 uppsatser innehållade orden Photon-counting detector.
1. En bildkvalitésutvärdering av två datortomografer i syfte att rättfärdiga ett inköp av en ny datortomograf : En fantomstudie
Kandidat-uppsats, KTH/Medicinteknik och hälsosystemSammanfattning : Antal datortomografiundersökningar har ökat under flera år i Sverige tack vare tekniska utvecklingar och ökad tillgänglighet på sjukvård. Södertälje sjukhus röntgenavdelningen är i behov av att byta ut en utdaterad datortomograf (eng: Computed tomography, CT) och avdelningen för medicinsk teknik har föreslagit ett inköp av en CT med fotonräknande-detektor. LÄS MER
2. Detective Quantum Efficiency in the Image Domain
Master-uppsats, KTH/FysikSammanfattning : 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. LÄS MER
3. Phase-Contrast Imaging, Towards G2-less Grating Interferometry With Deep Silicon
Master-uppsats, KTH/FysikSammanfattning : Conventional phase-contrast imaging entails stepping an analyser grating across the detector to resolve the interference pattern caused by the x-rays after passing through a series of gratings in a so-called Talbot-Lau interferometer. However, the analyser grating in the interferometer poses a challenge, not only due to the machinery and alignment required but also due to each exposure delivering a dose to the subject. LÄS MER
4. Neural Networks for Material Decomposition in Photon-Counting Spectral CT
Uppsats för yrkesexamina på avancerad nivå, KTH/Medicinteknik och hälsosystemSammanfattning : Photon counting computed tomography scanners constitute a major improvement of the field of computed tomography, opening various prospective and enabling the decomposition of computed tomography images into different materials. The material decomposition algorithm, mapping photon counts to material pathlengths, relies on a forward model with Poisson statistics. LÄS MER
5. High resolution x-ray imaging by measuring the induced charge distribution
Master-uppsats, KTH/FysikSammanfattning : 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. LÄS MER