RESUMO
Objective To investigate the patients' radiation dose received in digital radiography (DR) and provide basic data for developing diagnostic reference levels.Methods The patient' s ESD was estimated using the TLDs and DAP was measured by the dose-area product meter.The E values were then calculated by the DAP using Monte Carlo data and RefDose software.Measurements were made for twelve types of examination:skull PA,skull LAT,chest PA,chest LAT,abdomen AP,pelvis AP,cervix spine PA,cervix spine LAT,thoracic spine PA,thoracic spine LAT,lumber spine PA and lumber spine LAT.Results Both kV and mAs varied in the same type of examination for ESD,DAP and E(F =33.47,24.68,43.19,P ＜ 0.05).The dose each time for lumber spine LAT was the highest,reached 4.62 mGy in ESD and 2.26 Gy·cm2 in DAP,respectively.The E of abdomen AP averaged as 0.59 mSv,higher than that of lumber spine LAT.Even for the same type of examination,the dose from each equipment was different.Conclusions DR has the potential to reduce the patients' radiation doses.The guidance levels suitable for Chinese population should be established as soon as possible.
RESUMO
Objective To study the calculational method for the radiotherapy facilities of the medical linear accelerator' s useful beam towars its maze.Methods The shielding calculation was made under the relevant national standards for a radiotherapy treatment room and compared with the test results.Results The dose rates at the maze entrance as calculated and measured were 89 and 86 μSv/h inside the maze door,as well as 5.7 and 6.2 μSv/h outside the maze door,respectively.The calculated results were consistent with measured results.Conclusions By comparison of calculated results with measured results,the accuracy of the theoretical calculation method could be verified.