Santrauka:
Darbe tiriama tinklelio netinkamo fokuso atsumo artefaktas ir jo sasajos su mAs vertėm. Darbą sudaro mokslinės literatūros analizė, tyrimo metodikos aprašymas, tyrimo metodikos aprašymas, rezultatų analizė. Pateiktos gautos išvados ir rekomendacijos
Description:
In Lithuania, radiological technologists are still little aware of the grid's artifacts and the grid itself. Often, radiology technologists do not follow the focal length, thus obtaining an artefact with the distortion of focus. Purpose of work: To determine the grid artifacts in routine X-ray diagnostics. Tasks of work:
1. To describe the characteristics and importance of the grid in conventional X-ray diagnostic examination. 2. To determine the interval range of focus of the grid of different characteristics, in which image artifacts of the grid do not show up. 3. To evaluate the exposure changes in the grid focus interval range and outside the range.
Specialists in scientific literature have no consensus about the need to use in all X-ray examination of grid that improve the quality of images, while at the same time increasing the dose of radiation by patients. This controversy is very important in the X-ray tests of children who are sensitive to ionizing radiation. Setting and reaserch medhology. The research was conducted at Kaunas Clinics. The research investigated the grids with two different characteristics. The main reference point (focal distance) of each grid was chosen to be the as specified in the grid technical data. The distance was increased and reduced every 5 cm with a possible 1 cm error due to technical obstacles until an incorrect focal distance artifact occurs. The theoretical values of mAs were obtained using the formula
. The study outcomes. The study showed that in the grids of better technical parameters, the distortion of the wrong focus appears faster than for poorer ones. The focus interval range of the first grid, in which the wrong focal length range did not appear, was from 1 m to 1,22 m. The second grid range is from 1,50 m to 1,55 m. Conclusion. The allowed range in the first grid is from 1 m to 1,22 m, the second from 1,50 m to 1,55 m.
