ABSTRACT
Objective:According to the requirement of ISO and National Standard, new X-ray environmental standard for the calibration of environmental dosimeter was established in Beijing SSDL. Methods:Half value layer and air kerma dose-rate was determined in the X-ray environmental qualities by a standard dosimeter. Results: The technical requirement of ISO and National Standard are met within 2% for the X-ray environmental standard qualities in Beijing SSDL. Conclusion:The X-ray standard radiation field can be used for the calibration of environmental dosimeters and experiment of research.
ABSTRACT
Background: Different computational methods have been used for the prediction of X-ray spectra and beam quality in diagnostic radiology. The purpose of this study was to compare X-ray beam qualities based on half-value layers (HVLs) determined through measurements and computational model estimations. Methods: The HVL estimations calculated by IPEM78 (Spectrum Processor of the Institute of Physics and Engineering in Medicine’s Report 78) and SpekCalc software were compared with those determined through measurements. In this study, the HVLs of both Philips (Phil) (Philips Healthcare, Best, NL) and General Electric Company (GE) (GE Global Research, Niskayuna, US) diagnostic range X-ray machines (50 kVp to 125 kVp) were evaluated. Results: In the HVL estimations, SpekCalc and IPEM78 showed maximum differences of 10% and 9%, respectively, compared with direct measurements. Both models provided means and SDs of HVLs that were within 5% of the HVL measurements of GE and Phil machines. Conclusion: Both computational models provide an alternative method for estimating the HVL of diagnostic range X-ray. These models are user-friendly in predicting HVLs, which are used to characterise the quality of the X-ray beam, and these models provide predictions almost instantly compared with experimental measurements.