Sökning: "photon counting"

Visar resultat 6 - 10 av 44 avhandlingar innehållade orden photon counting.

1. 6. Digital Mammography with a Photon Counting Detector in a Scanned Multislit Geometry

   Författare :Magnus Åslund; Mats Danielsson; Ehsan Samei; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mammography; digital; photon counting; scanning; detective quantum effciency; scattered radiation; automatic exposure control; Physics; Fysik;

   Sammanfattning : Mammography screening aims to reduce the number of breast cancer deaths by early detection of the disease, which is one of the leading causes of deaths for middle aged women in the western world. The risk from the x-ray radiation in mammography is relatively low but still a factor in the benefit-risk ratio of screening. LÄS MER

3. 7. Quantification and Maximization of Performance Measures for Photon Counting Spectral Computed Tomography

   Författare :Moa Yveborg; Hans Bornefalk; Franz Pfeiffer; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spectral computed tomography; silicon detector; detectability index; photon counting; Hotelling SDNR; material basis decomposition;

   Sammanfattning : During my time as a PhD student at the Physics of Medical Imaging group at KTH, I have taken part in the work of developing a photon counting spectrally resolved silicon detector for clinical computed tomography. This work has largely motivated the direction of my research, and is the main reason for my focus on certain issues. LÄS MER

4. 8. Two-Photon Excited Fluorescence Depolarisation : Experimental and Theoretical Development

   Författare :Linus Ryderfors; Emad Mukhtar; Lennart B.-Å. Johansson; Yehudi K. Levine; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Two-photon excitation; Fluorescence; Fluorescence depolarisation; Fluorescence anisotropy; Time-correlated single photon counting; Gold nanoparticles; Rotational diffusion; Excited state symmetry; Extended Förster theory; Orientation correlation functions; Donor-donor energy migration DDEM ; Chemical physics; Kemisk fysik;

   Sammanfattning : We have studied fundamental aspects of time-resolved two-photon excited fluorescence depolarisation. The thesis presents experimental as well as theoretical progress. LÄS MER

5. 9. Photon Counting X-ray Detector Systems

   Författare :Börje Norlin; Christer Fröjdh; Hans-Erik Nilsson; Kenway Smith; Mittuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Monte Carlo simulation; Three-dimensional; Energy weighting; X-ray; Pixel detector; Charge sharing; Imaging; Medipix; Spectroscopy; Dental diagnosis; Image quality; Electronics; Elektronik;

   Sammanfattning : This licentiate thesis concerns the development and characterisation of X-ray imaging detector systems. “Colour” X-ray imaging opens up new perspectives within the fields of medical X-ray diagnosis and also in industrial X-ray quality control. LÄS MER

7. 10. An Event-Reconstructing Silicon Detector for 1 µm Resolution Spectral Computed Tomography

   Författare :Christel Sundberg; Mats Danielsson; Julia Herzen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; photon-counting; silicon detector; spectral computed tomography; subpixel resolution; dose efficiency; coincidence tracking; event reconstruction; fotonräknande; kiseldetektor; spektral datortomografi; subpixelupplösning; doseffektivitet; koincidensspårning; händelserekonstruktion; Fysik; Physics;

   Sammanfattning : Computed tomography (CT) is a medical imaging modality in which cross-sectional images of the human body are created using x-rays. Commercial CT scanners utilize energy-integrating detectors to measure the x-ray attenuation. However, photon-counting detectors with energy-discriminating abilities have started to emerge. LÄS MER