Avaliação da dose recebida por cães e gatos em exames radiográficos de tórax

Abstract

The present study was developed on radiographic examinations of the chest, performed in dogs and cats, taking into account that the examination has high specificity for the evaluation of bone, pulmonary, vascular and, many times, joint structures. Therefore, this study aims to evaluate the dose received by dogs and cats in chest X-rays. This evaluation was carried out through the exposure of three phantoms representing animals of sizes called P (small), M (medium) and G (large). As national legislation does not address radiological protection in animals and there is no guideline on image quality in animals in Brazil, it is believed that the doses are not adequate. For each category, an estimate was made of the entry dose into the skin that the animals receive through the use of an ionization chamber of 6 cm3 of sensitive volume, connected to an electrometer. Phantom exposures were made with the following parameters: voltage varying between 40 kvp – 48 kvp and current-time product of 6.4 mAs. Two exposures were performed for each animal size and the value provided by the ionization chamber was corrected by the chamber calibration factor and by the temperature and pressure factor, thus obtaining the entrance skin dose (ESD). dose). As the standard for this exam is three exposures in different projections, without changing the technical parameters, the ESD value, previously found, was multiplied by three and results ranging from 0.375 mGy to 0.903 mGy were obtained. These values found were compared with dosimetric studies and literature on the subject, obtaining as a conclusion that the study doses are low and may or may not affect image quality. It is recommended that an image quality study be carried out at the site under study.