Resumo

MORA, Patricia. Optimización de la técnica radiográfica del tórax PA. Acta méd. costarric [online]. 2002, vol.44, n.4, pp.149-154. ISSN 0001-6002.

Objective: Low kilovoltages (<100 kVp) to obtain chest films are commonly used in Costa Rica, regardless of international recommendations. This study aims to demonstrate that at higher kVps the visualization of low contrast objects is improved and that the absorbed doses are lower. Methods: Two chests films, one at high kVp and one at low kVp, were taken to 11 patients. At the skin of each patient, two TLD-100 chips were placed to record the entrance skin doses, the chips were analyzed at the Nuclear Physics Laboratory of the University of Costa Rica. Using the anatomic criteria test tool 28 radiologists compared the anatomic findings for each technique. Results: At higher kVps the average entrance skin doses were lower by 40% and the overall contrast of the image was decreased between 10% to 50%. The anatomic criteria test tool gave a total of 448 positive points, showing a clear preference for the high kilovoltaje technique. Conclusions: The optimization of chest studies based on the ratio risk versus benefit shows that high kilovoltage techniques should be implemented in our country due to the diminution in the delivered doses and an improved visualization of the anatomy shown in the chest film according to the interpreting radiologists.

Palavras-chave : radiología; tórax; dosis; contraste.