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Spectral Computed T...
Spectral Computed Tomography with a Photon-Counting Silicon-Strip Detector
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- Persson, Mats, 1987- (author)
- KTH,Medicinsk bildfysik,Physics of Medical Imaging
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- Danielsson, Mats, Professor (thesis advisor)
- KTH,Medicinsk bildfysik
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- Bornefalk, Hans, Dr. (thesis advisor)
- Philips Healthcare
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- Hsieh, Jiang, Dr. (opponent)
- GE Healthcare
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(creator_code:org_t)
- ISBN 9789175959917
- Stockholm : KTH Royal Institute of Technology, 2016
- English 43 s.
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Series: TRITA-FYS, 0280-316X ; 2016:20
- Related links:
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https://kth.diva-por... (primary) (Raw object)
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https://urn.kb.se/re...
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Abstract
Subject headings
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- Computed tomography (CT) is a widely used medical imaging modality. By rotating an x-ray tube and an x-ray detector around the patient, a CT scanner is able to measure the x-ray transmission from all directions and form an image of the patient’s interior. CT scanners in clinical use today all use energy-integrating detectors, which measure the total incident energy for each measurement interval. A photon-counting detector, on the other hand, counts the number of incoming photons and can in addition measure the energy of each photon by comparing it to a number of energy thresholds. Using photon- counting detectors in computed tomography could lead to improved signal-to-noise ratio, higher spatial resolution and improved spectral imaging which allows better visualization of contrast agents and more reliable quantitative measurements. In this Thesis, the feasibility of using a photon-counting silicon-strip detector for CT is investigated. In the first part of the Thesis, the necessary performance requirements on such a detector is investigated in two different areas: the detector element homogeneity and the capability of handling high photon fluence rates. A metric of inhomogeneity is proposed and used in a simulation study to evaluate different inhomogeneity compensation methods. Also, the photon fluence rate incident on the detector in a scanner in clinical use today is investigated for different patient sizes through dose rate measurements together with simulations of transmission through patient im- ages. In the second part, a prototype detector module is used to demonstrate new applications enabled by the energy resolution of the detector. The ability to generate material-specific images of contrast agents with iodine and gadolinium is demonstrated. Furthermore, it is shown theoretically and ex- perimentally that interfaces in the image can be visualized by imaging the so-called nonlinear partial volume effect. The results suggest that the studied silicon-strip detector is a promising candidate for photon-counting CT.
Subject headings
- NATURVETENSKAP -- Fysik -- Annan fysik (hsv//swe)
- NATURAL SCIENCES -- Physical Sciences -- Other Physics Topics (hsv//eng)
- TEKNIK OCH TEKNOLOGIER -- Medicinteknik -- Medicinsk apparatteknik (hsv//swe)
- ENGINEERING AND TECHNOLOGY -- Medical Engineering -- Medical Equipment Engineering (hsv//eng)
Keyword
- Photon-counting
- silicon-strip detector
- spectral computed tomography
- ring artifacts
- fluence rate
- basis material decomposition
- sub-pixel information
- Fysik
- Physics
Publication and Content Type
- vet (subject category)
- dok (subject category)
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