Dosimetry and image quality assessment in a direct radiography
                  system

Oliveira, Bruno Beraldo; Oliveira, Marcio Alves de; Paixão, Lucas; Teixeira, Maria Helena Araújo; Nogueira, Maria do Socorro

doi:10.1590/0100-3984.2013.1876

Acessibilidade / Reportar erro

Brasil

Español English

sumário « anterior atual seguinte »

Sumário

ORIGINAL ARTICLES • Radiol Bras 47 (6) • Dec 2014 • https://doi.org/10.1590/0100-3984.2013.1876 copy

Dosimetry and image quality assessment in a direct radiography system^* * Study developed in the Program of Post-graduation in Science and Technology of Radiations, Minerals and Materials – Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), Belo Horizonte, MG, Brazil.

Authorship SCIMAGO INSTITUTIONS RANKINGS

Objective:

To evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms.

Materials and Methods:

Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms.

Results:

Considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values.

Conclusion:

The present study contributes to verify the equipment conformity as regards dose values and image quality.

Mean glandular dose; Image; Direct radiography

PMMA plate thickness (mm)	Equivalent breast thickness (mm)	Fibroglandular tissue proportion of the breast equivalent (%)	Voltage (kV)	Load (mA.s_CAE)	Anode/filter combination
20	21	97	25	46	W/Rh
30	32	67	26	70	W/Rh
40	45	41	28	93	W/Rh
50	60	20	31	133	W/Rh
60	75	9	31	165	W/Ag
70	90	4	33	184	W/Ag

			CSR (mmAl)
PMMA plate thickness (mm)	Equivalent breast thickness (mm)	K_i (mGy)	Calculated	Tolerance
20	21	1.078	0.50	0.28–0.55
30	32	1.900	0.51	0.29–0.56
40	45	3.150	0.54	0.31–0.58
50	60	5.996	0.56	0.34–0.61
60	75	7.675	0.62	0.34–0.63
70	90	9.532	0.65	0.36–0.65

	Gold thickness evaluations (μm)
Diameter (mm)	Visual in the present study	Visual by Oliveira et al.⁽²⁷27 Oliveira MA, Dantas MVA, Santana PC, et al. Assessment of glandular dose and image quality in mammography using computerised radiography employing a polymethylmetacrilate breast simulator. Proceedings of the 16th Solid State Dosimetry Conference, 2011 Sep 19-24; Sidney, Australia. Radiat Meas. 2011;46:2081-5.⁾	Automatic – present study	Automatic by Oliveira et al.⁽²⁷27 Oliveira MA, Dantas MVA, Santana PC, et al. Assessment of glandular dose and image quality in mammography using computerised radiography employing a polymethylmetacrilate breast simulator. Proceedings of the 16th Solid State Dosimetry Conference, 2011 Sep 19-24; Sidney, Australia. Radiat Meas. 2011;46:2081-5.⁾	Reference value
0.10	2.00	2.00	0.995	2.00	1.680
0.25	0.36	0.36	0.142	0.16	0.352
0.50	0.16	0.16	0.064	0.10	0.150
1.00	0.10	0.08	0.037	0.03	0.091
2.00	0.06	0.06	0.040	0.05	0.069

Structures (total)	Visualized structures	Tolerance
Fibers (6)	4	≥ 4
Discs (8)	7	≥ 7
Tumor masses (5)	4	≥ 4
Microcalcifications (5)	4	≥ 4
Metal grids (4)	3	3

Publicação do Colégio Brasileiro de Radiologia e Diagnóstico por Imagem Av. Paulista, 37 - 7º andar - conjunto 71, 01311-902 - São Paulo - SP, Tel.: +55 11 3372-4541, Fax: 3285-1690, Fax: +55 11 3285-1690 - São Paulo - SP - Brazil
E-mail: radiologiabrasileira@cbr.org.br

Acompanhe os números deste periódico no seu leitor de RSS

[1] Mailing Address: Bruno Beraldo Oliveira. Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN). Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Pampulha. Belo Horizonte, MG, Brazil, 31270-901. E-mail: boliveira.mg@gmail.com.

Brasil

Brasil

Dosimetry and image quality assessment in a direct radiography system* * Study developed in the Program of Post-graduation in Science and Technology of Radiations, Minerals and Materials – Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), Belo Horizonte, MG, Brazil.

Objective:

Materials and Methods:

Results:

Conclusion:

Dosimetry and image quality assessment in a direct radiography system^* * Study developed in the Program of Post-graduation in Science and Technology of Radiations, Minerals and Materials – Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN), Belo Horizonte, MG, Brazil.