|
|
Digital radiography- image processing simulation
Lamoš, Martin ; Kolář, Radim (referee) ; Drastich, Aleš (advisor)
This paper describes a MATLAB application with the main purpose of the simulation of noise components and noise elimination methods of Digital Radiography. The main parts of simulator are the model of a scene, procedures for loading the noise components to image data and methods for image processing. Various methods are employed depending on the type of noise. Subtraction techniques are used for the elimination of structural noise. The physical noise suppression is obtained using several methods of cumulation and Pixel Shift is used to reduce motion artifacts caused by the existence of moving noise. The techniques of superposition highlight the areas of interest in an image. Included are also auxiliary procedures for simulator running and presentation of final data. The model and the presented application can be used mainly for educational purposes as a powerful didactic tool.
|
|
|
Modern trends in radiographic procedures and methods in defectoscopy
Skřivánková, Vendula ; Vlašic, František (referee) ; Juliš, Martin (advisor)
Presented thesis deals with modern trends and techniques in radiographic methods of crack detection which are recently used in engineering practice. In the first part, conventional (analogue) radiography principles based on creating a visible image of tested object to radiographic film are discussed. The next part is aimed to the digital radiography and radioscopy. To digitize existing X-ray film images, application of storage phosphor plates (CR), flat panels (DR) and computed tomography (CT).
|
|
|
Imperfections of the skiagraphs.
JECHOVÁ, Kateřina
The purpose of my Thesis was to find and document occurrence of imperfect skiagrams in all types of radiographic views, this means classic films, computed radiography (CR) and direct radiography (DR). The research question is "Is there any correlation between number of imperfect skiagrams and number of total skiagrams taken?" I documented rate of imperfect skiagrams in hospital České Budějovice in the time between the years 2013 2015. The Thesis is divided to two main sections: History of Display media and the principle of displaying with all types of displays. Imperfect skiagrams were sorted by origin to: Imperfections caused by operations, imperfections caused by patient and imperfections caused during processing. In my thesis I found out that there is not direct correlation between icreasing number of examinations and number of processed skiagrams. In the reporting period between 2013 2015 there is dependency only in year 2013. In the next two years there is discrepancy in the tracked parameter. The increasing number of examinations and the introduction of new investigative techniques and the rotation of employees (the onset of graduates, as well as radiologists and doctors, their incorporation) are the occurrence of erroneous skiagrams inconsistent with the increasing number of examinations. The monitoring of imperfect skiagrams at the Hospital of České Budějovice is an indicator of the quality of displaying where the upper limit is set at 2.5%. In the reference period, it ranges from 0.2% to 1.76%. Employees are introduced every month and cumulatively once a year to the numbers and types of bad skiagrams to eliminate these errors as much as possible.
|
|
|
Digital radiography- image processing simulation
Lamoš, Martin ; Kolář, Radim (referee) ; Drastich, Aleš (advisor)
This paper describes a MATLAB application with the main purpose of the simulation of noise components and noise elimination methods of Digital Radiography. The main parts of simulator are the model of a scene, procedures for loading the noise components to image data and methods for image processing. Various methods are employed depending on the type of noise. Subtraction techniques are used for the elimination of structural noise. The physical noise suppression is obtained using several methods of cumulation and Pixel Shift is used to reduce motion artifacts caused by the existence of moving noise. The techniques of superposition highlight the areas of interest in an image. Included are also auxiliary procedures for simulator running and presentation of final data. The model and the presented application can be used mainly for educational purposes as a powerful didactic tool.
|
|
|
Modern trends in radiographic procedures and methods in defectoscopy
Skřivánková, Vendula ; Vlašic, František (referee) ; Juliš, Martin (advisor)
Presented thesis deals with modern trends and techniques in radiographic methods of crack detection which are recently used in engineering practice. In the first part, conventional (analogue) radiography principles based on creating a visible image of tested object to radiographic film are discussed. The next part is aimed to the digital radiography and radioscopy. To digitize existing X-ray film images, application of storage phosphor plates (CR), flat panels (DR) and computed tomography (CT).
|
|
|
The ambulatory radiology institution - the transition from the analog to the digital system
DOUCHOVÁ, Irena
This work offers general information about digitizing an outpatient radiodiagnostic department. It presents physical principles of digital imaging and the equipment that is necessary for the transition to a new technology. The introduction explains the functional principle of memory foils, digitizers and data archiving. Some attention is also paid to economic and organizational problems related to maintaining partial operation of the analogue system at a digitalized department. At the same time, some mistakes are described that can be eliminated having greater knowledge of the system of work at a digitalized department. A comparison of the amount of finance expended on chemicals, films and servicing of a developing automatic machine with operating costs after digitizing led me to a conclusion that the cost of digitizing will not return after five years by saving finance related to the analogue process. Most of the memory foils have to be replaced after four years due to their ``worn-outness{\crqq}. The most important benefit digitizing brings is the improvement and acceleration of the access to information, which means saving of labour time. The new technology makes it possible to shorten the time of examination helping thus in critical situations.
|
|
| |
|
|
New Experimental Setup for Study of Physical Processes Preceding Specimen Failure
Vavřík, Daniel ; Bryscejn, Jan ; Holý, T. ; Jakůbek, J. ; Jakůbek, M. ; Valach, Jaroslav ; Vykydal, Z.
Failure of a high ductile specimen usually precedes a decrease of the loading force under the condition of displacement control in the monotonic loading. Unfortunately, the elastic energy stored in the standard loading equipment can result in sudden failure within very short time corresponding to the loading unstability. We can prolong this time interval by reducing the elastic energy in the loading equipment. The proposed new loading frame fulfils the indicated requirement and enables extraordinary precise displacement loading control even beyond the maximal loading force. Plastic deformation on a surface is investigated by the optical Method of Interpolated Ellipses and together with damage processes inside of the specimen are simultaneously observed by the X-ray Dynamic Defectoscopy method.
|
guest ::
