Keywords:
Radiation Protection, Paediatric, Radioprotection / Radiation dose, Thorax, Digital radiography, Radiation safety, Quality assurance, Prospective, Experimental, Performed at one institution
Authors:
C. I. D. C. T. Martins1, F. M. Nogueira2, J. Santos3; 1Lisboa/PT, 2Casal da Barota - Belas/Massamá Norte, Lisboa/PT, 3Coimbra/PT
DOI:
10.26044/ecr2020/C-13721
Results
1. Optimisation Tests
32 optimization tests were performed: 22 on the CIRS ATOM® 705 phantom and 10 on the KYOTO KAGAKU® PBU-60 phantom. For the CIRS ATOM® 705 phantom, the exposure field was 19 x 22 cm, while for the KYOTO KAGAKU® PBU-60 phantom the field was 34 x 38 cm. Focus-Detector Distance was on all 180 cm exposures.
The exposure parameters tested as well as the obtained KAP values are shown in Figures 8 (CIRS ATOM® 705 phantom) and 9 (KYOTO KAGAKU® PBU-60 phantom).
2. Image Quality Evaluation
SNR values obtained for each image are shown in Figures 8 and 9.
All observers rated above 4 all criteria in all images except criterion 1 (Visually sharp reproduction of the vascular pattern of the lungs) for CIRS ATOM® 705 phantom images due to its characteristics.
After analysis of the obtained data, the radiographic exposure protocol was established and is presented in Figure 10.
3. Clinical Application
Radiographic and dose data were collected for about 1 month after protocol application, and a sample of 44 examinations was obtained, of which 26 (59.1%) were performed on male children. In weight class 1 (under 5 kg) only one child was examined and this weight class was excluded.
The KAP values obtained before and after optimization are described in Figures 11 and 12.
The application of this protocol resulted in very relevant dose reductions for all weight classes, namely: 60% for class 2, 75% for class 3, 59% for class 4 and 54% for class 5. Statistically, the differences between both phases (before vs after optimization) were significant in all weight classes (p = 0.000).