Full text
| |
| Author(s): |
Paulo Domingues de Oliveira Júnior
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Escola de Engenharia de São Carlos (EESC/SBD) |
| Defense date: | 2009-12-04 |
| Examining board members: |
Marcelo Andrade da Costa Vieira;
Mauricio Cunha Escarpinati;
Martin Eduardo Poletti
|
| Advisor: | Marcelo Andrade da Costa Vieira |
| Abstract | |
The aim of this work is to develop a set of procedures for quality assurance of mammographic equipment by the digital image processing of radiographic images of standard test objects (phantoms) acquired by the radiographic equipment. It allows the evaluation of several physical parameters of the radiographic image quality by a simple and quick procedure, with good accuracy, using the equipment the shortest time as possible. The main evaluated parameters related to the quality of an imaging system are: spatial resolution - by measuring the modulation transfer function (MTF) - image contrast - by the measurement of the H&D curve and noise - evaluated by the noise power spectrum (NPS). Thus, it attends the recommendations of the ICRU (International Commission on Radiation Units and Measurements), which deals as the guidelines for quality assurance of radiographic images all over the world. Through these quality parameters is possible to measure the detective quantum efficiency (DQE) of any mammographic system, which allows a full evaluation of the image quality related to the dose absorbed by the patient. The results confirm the possibility of the practical application of the developed system, which provides a full evaluation of the image quality, acquired by the mammographic equipment. All results showed low error estimation, substantiated by the analysis of the uncertainty in measurements procedures. Moreover, the evaluation through the DQE allowed to perform a comparison of mammography systems involved in this research. Thus, based on these results, it is possible to confirm that its system can perform a fundamental part of the quality assurance in mammographic images system. (AU) | |
| FAPESP's process: | 06/05135-8 - Quality control in mammographic imaging systems: a computational scheme for automatic determination of physical parameters of image quality |
| Grantee: | Paulo Domingues de Oliveira Junior |
| Support Opportunities: | Scholarships in Brazil - Master |