Discussion of Hp(3) calibration with two thermoluminescent dosimeters in the same standard X-ray RQR radiation field / 中国辐射卫生

Objective To compare Hp(3) calibration with a homemade (A) thermoluminescent dosimeter (TLD) and an imported (B) TLD in a standard X-ray RQR radiation field, to explore the different responses of A and B, and to provide foundation for the calibration of Hp(3). Methods A column mode was selected. Hp(3) calibration was performed using A and B in a standard X-ray RQR radiation field in the Secondary Standard Dosimetry Laboratory, National Institute for Radiological Protection, China Center for Disease Control and Prevention. Angle response, energy response, and linear response were calibrated with RQR4 (60 kV), RQR7 (90 kV), and RQR9 (120 kV), respectively. Results In terms of angle response, the calibration results of A were relatively high, while the calibration results of B were relatively low. In terms of energy response, the calibration results showed a similar pattern to angle response. In terms of linear response, the calibration results of both A and B were satisfactory. Conclusion Both A and B can be used for normal calibration of Hp(3) in a standard X-ray RQR radiation field. However, in actual monitoring, attention should be paid to the energy and angle response values of TLDs.

Research of TLD calibrated in different standard X-ray RQR radiation field in terms of eye lens dose Hp (3) / 中华放射医学与防护杂志

Objective To compare the calibration result of standard X-ray RQR radiation field between SSDL (NIRP) and CEA LIST LNHB (France),and to explore the feasibility of calibrating Hp (3) in standard X-ray RQR radiation field of SSDL (NIRP).Methods Using a column model with a diameter and high of 20 cm,TLD was calibrated in SSDL (NIRP) and CEA LIST LNHB (France) to measure the personal dose equivalent eye lens dose Hp (3),X-ray RQR radiation field included RQR4 (60 kV),RQR7 (90 kV),RQR9 (120 kV),with energy response,angle response and linear response.Results In terms of energy response,the calibration results of TLD in both SSDL (NIRP) and CEA LIST LNHB (France) were in good agreement.The difference between exposure value and response value was less than 10％.In terms of angle response,the calibration result of TLD in CEA LIST LNHB (France) was better in SSDL (NIRP).The difference between exposure value and response value in CEA LIST LNHB (France) was less than 6％,while the difference between exposure value and response value in SSDI (NIRP) was more than 10％ at angle of 20°.In terms of linear response,both calibration result of SSDL (NIRP) and CEA LIST LNHB (France) were in good agreement.Conclusions The standard X-ray RQR field in SSDL (NIRP) can be used for the calibration of Hp (3).

Research of TLD calibrated in different standard X-ray RQR radiation field in terms of eye lens dose Hp(3) / 中华放射医学与防护杂志

Objective@#To compare the calibration result of standard X-ray RQR radiation field between SSDL (NIRP) and CEA LIST LNHB(France), and to explore the feasibility of calibrating Hp(3) in standard X-ray RQR radiation field of SSDL(NIRP).@*Methods@#Using a column model with a diameter and high of 20 cm, TLD was calibrated in SSDL (NIRP) and CEA LIST LNHB (France) to measure the personal dose equivalent eye lens dose Hp(3), X-ray RQR radiation field included RQR4(60 kV), RQR7(90 kV), RQR9(120 kV), with energy response, angle response and linear response.@*Results@#In terms of energy response, the calibration results of TLD in both SSDL (NIRP) and CEA LIST LNHB (France) were in good agreement. The difference between exposure value and response value was less than 10%. In terms of angle response, the calibration result of TLD in CEA LIST LNHB (France) was better in SSDL(NIRP). The difference between exposure value and response value in CEA LIST LNHB (France) was less than 6%, while the difference between exposure value and response value in SSDL(NIRP) was more than 10% at angle of 20°. In terms of linear response, both calibration result of SSDL (NIRP) and CEA LIST LNHB (France) were in good agreement.@*Conclusions@#The standard X-ray RQR field in SSDL (NIRP) can be used for the calibration of Hp(3).

Establishment of standards of Hp(3) for the calibration of eye-lens dose equivalent dosimeters / 中国医学装备

Objective:To establish the X-ray standard was used to calibrate Hp(3) dosimeter in order to satisfy the requirement of eye-lens dose equivalents for the radiological occupational staff.Methods:The conventional values (Hp(3)) on the reference point of the narrow beams of X-ray fields were obtained by means of the product of air kerma (Kair) and the conversion coefficients (hp(3,ɑ)) recommended by ICRP116 recommendation. And these researches can be used by standard ionization chamber dosimeter. Finally, provided the conventional true value Hp(3) at calibrate point.Results:The standards and calibration program of calibrations eye-lens dose equivalent dosimeter were established under the X-ray radiation field. The detection error between slab phantom recommended by ISO and head phantom recommended by the 116th publication of ICRP was lower when the TLD was used to detect result.Conclusions:The standards for calibration Hp(3) dosimeters can satisfy the requirement of calibration for radiological occupational staff. It also provides theoretical foundation for detection data that assessed Hp(3) dosimeters and then improves trace ability and reliability of detection data of Hp(3) in national radiation supervision and inspection network.

Effect of auxiliary radiological protective devices on reducing dose to the eye lens of interventional staff / 中华放射医学与防护杂志

Objective To establish a method for reducing the dose to the eye lens of interventional staff,and provide the data basis for improving radiological protection measures.Methods One piece of interventional equipment coupled with conventional auxiliary protective devices and two types of common neural interventional procedures were selected to monitor 46 and 35 procedures before and after the device modification.The doses to the eye lens of staff were measured with direct-reading dosimeters for analysis of dose trends.Results After modification of the devices,the average dose to the left eye lens decreased from (9.71 ±10.86) to (3.23 ±5.59) μSv for the first operator,from (9.51 ± 12.34) to (0.68 ± 0.78) μSv for the second in cerebral angiography;whereas the dose decreased from (14.83 ± 19.13) to (4.17±4.59) for the first operator and from (14.12±21.76) to (1.23 ±1.57)μSv for the second in embolization procedure,respectively.The left eye lens doses measured before and after the modification showed significant difference (U =-2.760,-2.467,-1.967,-2.655,P ＜0.05).Conclusions The modification of the auxiliary radiological protective devices may effectively reduce the dose to the eye lens dose.This method was shown to be feasible for the improvement of radiological protection of interventional staff.

Study of real-time measurements of occupational staff's eye lens doses by direct-reading dosimeters in interventional procedures / 中华放射医学与防护杂志

Objective To establish the methods for measuring the dose to occupational staff's eye lens in interventional procedures with direct-reading dosimeters,and to realize the real-time monitoring of eye lens dose and warning for high dose rate,thus providing the scientific basis of the staff radiological protection in interventional procedures.Methods Direct-reading dosimeters were calibrated with personal dose equivalent HP (3).The eye lens doses for occupational staff in different kinds of interventional procedures were measured by the devices with both single-and double X-ray tubes.The data obtained fromthe direct-reading dosimeters was compared to those obtained from TLDs.Results Direct-reading dosimeters showed good linear fitting with the calibration of HP (3),and the coefficients of variation were lower than 5％.The average eye lens HP (3) for the main operator in coronary arteriography and stent implantation in brain obtained by direct-reading dosimeters were 12.0 and 24.5 μSv,respectively,whereas those obtained by TLDs were 11.9 and 22.7 μSv,respectively.The direct-reading dosimeters gave similar t~nds as TLDs do so.The direct-reading dosimeters were able to provide eye lens HP (3) in each individual interventional procedure,and to monitor the real-time dose rate as well.Conclusions The calibration of HP (3) and the data gained by direct-reading dosimeters are reliable.Therefore,the methods for real-time measurement of eye lens dose for occupational staff in interventional procedures are successfully established.

The measurements of eye lens dose for occupational staff in interventional procedures / 中华放射医学与防护杂志

Objective To establish methods of measuring the eye lens dose to interventional staff,to obtain relevant dose data and to provide a scientific basis for reducing eye lens dose.Methods Two kinds of dosimeters,thermoluminescent dosimeter (TLD) and optically stimulated luminescence dosimeter (OSLD),were selected to measure the personal dose equivalent HP (3) to eye lens of occupational staff in several kinds of interventional procedures,including cardiovascular interventional procedures,cerebrovascular interventional procedures etc.Five types of Digital Subtraction Angiography (DSA) equipment were chosen in the study,including single tube equipment and double tube equipment.Results The eye lens dose HP (3) to interventional staff varied significantly with different interventional procedures.The lowest dose is shown in the coronary angiography procedure,while the highest dose shown in the cerebral stenting procedure.For the same type of interventional procedure,the eye lens dose to the primary interventionist was the highest.For same interventionist,the dose to the left eye was obviously higher than that to the right eye.In addition,the measured results of OSLD were apparently higher than that of TLD.Conclusions Both TLD and OSLD could be used to measure eye lens dose,and the ways of calibrating TLD to evaluate personal dose equivalent HP (3) were feasible.The reason of significant difference between the measured results of TLD and OSLD needs further research.