Sökning: "Transmission tomography"
Visar resultat 1 - 5 av 71 avhandlingar innehållade orden Transmission tomography.
1. Improvements of SPECT by a new collimator design and simultaneous transmission-emission tomography
Sammanfattning : SPECT (Single Photon Emission Computed Tomography) and planar scintigraphy are the most established and world wide-spread nuclear medicine imaging techniques for clinical use today. SPECT is a tomographic technique that allows 3-D visualization of biochemical processes or physiological flow in the human body by external detection of photons from an administered radiopharmaceutical. LÄS MER
2. Attenuation correction in pulmonary and myocardial single photon emission computed tomography
Sammanfattning : The objective was to develop and validate methods for single photon emission computed tomography, SPECT, allowing quantitative physiological and diagnostic studies of lung and heart. A method for correction of variable attenuation in SPECT, based on transmission measurements before administration of an isotope to the subject, was developed and evaluated. LÄS MER
3. Transmission Electron Tomography and In-situ Analysis of Nanowires
Sammanfattning : As semiconducting nanowires have promising applications for materials science, nanoelectronics and photovoltaic devices, absolute control of their structure, morphology and composition is a prerequisite for their functionality. Nanowires, grown through the vapor-liquid-solid (VLS) method, exhibit a complex relationship between their liquid seed particle and what properties, such as the aforementioned ones, the wire adopts in the end. LÄS MER
4. 3D nano-tomography using coherent X-rays
Sammanfattning : X-rays allow to non-destructively investigate biological, chemical or physical processes at the nano-scale. Their high penetration depth in matter allows to investigate samples even inside sample environments, which would be difficult with complementary methods such as transmission electron microscopy (TEM). LÄS MER
5. Development and evaluation of an independent system for absorbed dose calculations in radiotherapy
Sammanfattning : The aim of this work was to develop, implement and evaluate an independent system with which to calculate the absorbed dose, delivered by high-energy X-ray beams, to the prescription point and the depth of dose maximum. The introduction of such a system in the clinical routine may help ensure high-quality treatment and avoidance of errors which may jeopardise the clinical outcome of the treatment (i. LÄS MER