Sökning: "fotonräknande"
Visar resultat 1 - 5 av 15 uppsatser innehållade ordet fotonräknande.
1. Improving proton therapy planning with photon-counting spectral computed tomography
Master-uppsats, KTH/FysikSammanfattning : Proton radiation therapy is an alternative to conventional photon radiation therapy, which accounts for the majority of radiation treatments today. The rationale for using protons in radiation therapy lies in their dose deposition properties; photons deposit a radiation dose inversely proportional to the energy, and therefore tissue depth, while protons exhibit a sharp Bragg peak when traversing matter. LÄS MER
2. Characterization of Carotid Atherosclerotic Stenosis on Photon-Counting Computed Tomography
Master-uppsats, Lunds universitet/SjukhusfysikerutbildningenSammanfattning : Introduction and aim Atherosclerotic stenosis located at the carotid bifurcation accounts for 10% − 20% of all Transient Ischemic Attacks (TIA) and ischemic strokes, which occurs when Atherosclerotic stenosis, or so-called plaque, ruptures. The current method to evaluate carotid atherosclerotic stenosis is to measure the degree of stenosis. LÄS MER
3. Deep Ring Artifact Reduction in Photon-Counting CT
Master-uppsats, KTH/FysikSammanfattning : Ring artifacts are a common problem with the use of photon-counting detectors and commercial deployment rests on being able to compensate for them. Deep learning has been proposed as a candidate for tackling the inefficiency or high cost of traditional techniques. LÄS MER
4. 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
5. 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