|
|
Algorithms for multimodal radiography with novel imaging detectors.
Tureček, Daniel ; Šefc, Luděk (advisor) ; Tlustos, Lukas (referee) ; Linhart, Vladimír (referee)
Medical imaging is a technique that allows us to visualize non surgically the internal structure of the human body in order to diagnose or treat medical conditions. It permits also monitoring of physical processes or functions of different organs inside the body. The medical imaging encompasses wide range of techniques based on different physical prin- ciples, including techniques using ionizing radiation. The quality of the images depends significantly on the quality of the used imaging detectors. There are many types of the detectors, from old analog devices (e.g. films) to fully digital detectors such as flat panels, that are the most widely used today. The newer technology is being developed and the techniques such as photon counting explored. However, the state of the art technology is the single photon counting, where the experimental detectors such as Medipix are able to count and process each individual photon. This works studies the properties, features and applications of the newest detector from the Medipix family Timepix3 in different imaging modalities. Firstly, a design of a new hardware readout interface for Timepix3 is presented together with data acquisition software and new analysis and calibration algorithms. Then, different applications of Timepix3 detector were explored: very...
|
|
|
A system for 3D localization of gamma sources using Timepix3-based Compton cameras
Mánek, Petr ; Zavoral, Filip (advisor) ; Vinárek, Jiří (referee)
Compton cameras localize γ-ray sources in 3D space by observing evidence of Compton scattering with detectors sensitive to ionizing radiation. This thesis proposes a software system for operating a novel Compton camera device comprised of Timepix3 detectors and Katherine readouts. To communicate with readouts using UDP-based protocol, a dedicated hardware library was developed. The presented software can successfully control the acquisition of multiple Timepix3 detectors and simultaneously process their measurements in a real-time setting. To recognize instances of Compton scattering among observed interactions, a chain of algorithms is applied with explicit consideration for a possibly high volume of measured information. Unlike alternate approaches, the presented work uses a recently published charge drift time model to improve its spatial resolution. In order to achieve localization of γ-ray sources, the software performs conical back projection into a discretized cuboid volume. Results of randomized evaluation with simulated data indicate that the presented implementation is correct and constitutes a viable method of γ-ray source localization in 3D space. Experimental verification with a prototype model is in progress.
|
guest ::
