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ST 3.2 –
Protección radiológica en radiodiagnóstico
(orientada a la tomografía computada)
EVALUATION OF IMAGE SYSTEM SPATIAL RESOLUTION USING
TEXTURE ANALYSIS IN THE
BCR BREAST PHANTOM MAMMOGRAPHIC IMAGE
Viloria, Carolina
1
*; Leyton, Fernando
1
; Paixão, Lucas
2
;
Nogueira, Maria do Socorro
3
1
Pós-Graduação em Ciências e Técnicas Nucleares.
Universidade Federal de Minas Gerais. Brasil.
2
Pós-Graduação em Ciência e Tecnologia das Radiações. Centro de Desenvolvimento da
Tecnologia Nuclear. Brasil.
3
Centro de Desenvolvimento da Tecnologia Nuclear. Brasil.
* Responsible author, email: cmvb@cdtn.br
Mammography is the main radiographic technique for imaging the breast, being indicated for
cancer diagnosis and clinical monitoring. The Brazilian College of Radiology (BCR) developed
the Quality Program in Mammograph (QPM). This program provides reference levels for
radiation exposure and evaluates the image system quality through a visual inspection of
images obtained with the BCR phantom. Texture is an important characteristic in a given
region. Texture analysis technique can be used to obtain spatial resolution results from
phantom’s grids present in the images. Therefore, the aim of this work is to develop texture
analysis algorithms to perform an automatic quality evaluation of BCR phantom images. For this
study, BCR phantom images were collected from different facilities in Belo Horizonte, Brazil.
The methodology consists in selecting a region of interest (ROI) and then performing image
background subtraction and filtration. Thereafter, statistical values are calculated to quantify the
gray level spatial distribution. Spectral parameters are useful to differentiate between models of
periodic and non-periodic texture. They were used to quantify the differences between periodic
models. These algorithms were developed in MATLAB and the test objects evaluations were
made following the QPM parameters. The visual and computerized evaluations were compared.
The results showed that the developed algorithms can differentiate the four different grids of
BCR phantom. The use of these digital image processing techniques in the test object images
allows an objective evaluation executed by the computer. Therefore, the developed algorithms
help to improve the evaluation performed by quality assurance programme specialists.
Keywords:
Mammography, Digital Image Processing Texture Analysis.