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Keywords:
Radioprotection / Radiation dose, Professional issues, Radiation physics, CT, Experimental, Technical aspects, Technology assessment, Radiation safety, Occupational / Environmental hazards, Quality assurance, Dosimetric comparison
Authors:
R. Pescada, P. Sousa, A. F. Abrantes, L. P. V. Ribeiro, R. P. P. Almeida, S. Rodrigues, K. B. Azevedo, J. P. Pinheiro; Faro/PT
DOI:
10.1594/ecr2015/B-0869
Conclusion
In routine head CT examinations,
to use the barium lens protector,
allowed a reduction in the radiation dose of only 3% at a depth of both 10mm and 0.07mm ( Fig. 36 & Fig. 37,
respectively).
In the same examination,
for a depth of 10mm the use of lead thyroid protection allowed a decrease in dose of 22% and the use of bismuth breast protection allowed a reduction in breast of 65%.
For a depth of 0.07mm the use of lead thyroid protection allowed a decrease in dose of 21% and the use of bismuth breast protection allowed a reduction in breast of 30%.
In routine thorax CT examinations,
for a depth of 10mm (Fig. 38),
the use of thyroid lead protection allowed the redution of 73% in dose,
the bismuth breast protection allowed the redution of 37% in breast dose and the use of barium lens protection allowed the redution of 49% in lens dose.
At a depth of 0.07% (Fig. 39),
the use of thyroid lead protection allowed the redution of 56% in dose,
the bismuth breast protection allowed the redution of 34% in breast dose and the use of barium lens protection allowed the redution of 37% in lens dose.
In routine abdomen CT examinations,
for a depth of both 10mm (Fig. 40) and 0.07mm (Fig. 41),
the use of bismuth breast protection allowed a reduction of 36% in breast radiation dose.
In pelvic region,
the radiation dose has increased by 16% for a depth of 10mm and in 24% for a depth of 0.07mm,
because the lead apron was placed just in the front of the anthropomorfic phantom,
which increased the pelvic radiation dose due to the considerable backscattered radiation caused by the lead in the apron,
towards the measuring devices.
A limitation arose,
because there was no more OSL dosimeters available for this research.
However it is important to share this information,
because future researches on this theme,
should place lead aprons all around the patient beforre access the secondary radiation.
As for image quality,
the results were not so encouraging,
since the use of bismuth shield decreased the image quality regarding the calibration of HU values,
low contrast resolution and image uniformity.
Despite the results demonstrate that the protections are very useful in dose reduction,
they have negative effects when intended to reduce primary radiation on the patient.