ABSTRACT
Objective To study the radiation dose distribution in the X-ray room,and provide the strategy of radiation protection for the medical staff and the patient’s nursing who had to enter the room while the X-ray was exposing.Methods The thermolumi-nescent dosemeters(TLDs)was placed around the center of the X-ray tube with the same level of the bed.Then,exposure parame-ters,including the X-ray tube voltage value and the field of view,were changed for different groups while exposing.All of the TLDs were taken back to the lab for analysis.Results The differences between the two groups which had the same distance in different di-rections were statistically significant (P <0.01).With the same radiographic condition and direction,the radiation dose on the site of 10 cm from X-ray tube center was the maximum,while the site of 120 cm was the minimum.With the same radiographic condition and distance,the radiation dose on the anode side of the X-ray tube in the room was relative lower,while the site behind the X-ray tube was relative higher.With the same voltage value,distance and direction,the same sites that had the smaller FOV(34 cm×34 cm) received lower radiation dose than those with larger FOV(52.6 cm× 52.6 cm).Meanwhile,the sites with the voltage of 70 kV re-ceived the lower radiation dose than that with the voltage value of 120 kV.Conclusion In the X-ray room,the medical staff and the patient’s nursing can choose the area on the right side(anode side),keep far away from the X-ray tube center,avoid the rear of the X-ray tube and the cathodic direction of the X-ray tube to reduce the radiation dose.
ABSTRACT
The potential problems of QA (quality assurance) and safety control of medical equipment in hospital were analyzed. On this base, this paper developed the testing system for the performance tests and the safety inspections of medical equipment in hospital, and discusses the results and the problems existing in the running systems.
Subject(s)
Equipment Safety , Equipment and Supplies , Quality ControlABSTRACT
Objective To study the effects on tissue CT number caused by scan protocols.Methods The phantom was repeatedly scanned in different protocols by changing only one of parameters,such as X-ray tube voltage,mAs and recon kernel,while other parameters were ketp unchanged.The CT number of different materials in phantom were measured and analyzed.Results The CT numbers of tissues changed remarkably with the tube voltage and had different relativity for different tissues.The CT numbers had positive correlation with kV for such maierials as polyethyle,lexan,perspex,but for teflon the correlation was negative.The mAs and recon kernel had no effects on CT number.Conclusions The CT number of tissue changes with scanning X-ray tube voltage,so the setting of scan parameters should be taken into account in image diagnosis and radiotherapy.