Factors influencing non-invasive tube voltage measurement for mammography(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第11期
- Page:
- 1325-1332
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Factors influencing non-invasive tube voltage measurement for mammography
- Author(s):
- DONG Fenghua; ZHANG Xiaodong; DONG Wenlong; YANG Jian; FAN Jie
- National Institute of Measurement and Testing Technology, Chengdu 610021, China
- Keywords:
- Keywords: non-invasive tube voltage mammography filtration average kilovolt peak practical peak voltage
- PACS:
- R318
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.11.002
- Abstract:
- Abstract: Objective To study the variations and differences of Fluke X2 and RTI piranha 657 measurement results caused by the changes of distance, filtering conditions and anode angle in two kinds of radiation fields (Mo/Mo and W/Rh) with the increase of tube voltage according to IEC 61676 standard. Methods The stability of tube voltage was determined by an intrusive method. The distance, filtering conditions and anode angle were changed for the non-invasive measurement of tube voltage in two kinds of radiation fields. According to the measurement results, the change trends of the measurement results obtained by two kinds of instruments in two kinds of radiation fields were calculated, and the counting ratio difference (change rate of R value) of the instrument due to the filtering conditions change in two kinds of radiation fields was obtained by Monte Carlo simulation. Results In W/Rh radiation field, even if distance and anode angle differed greatly and filtering conditions changed slightly, their effects on the measurement results of two kinds of instruments met the requirements of IEC 61676 and were within 0.5 kV. However, in Mo/Mo radiation field, the measurement difference of the two kinds of instruments caused by the same filtering conditions changes was relatively larger, especially the maximum change of Fluke X2 measurement results which even reached 1.6 kV. Conclusion When calibrating the non-invasive tube voltage measuring instrument, a unified calibration distance, the anode angle of the bulb tube and the filtering conditions should be considered as important reference conditions in each laboratory, especially the limitation of filtering is extremely important in Mo/Mo radiation field, so as to reduce the effect on the non-invasive measurement of the average kilovolt peak of tube voltage, ensure the consistency of the results among the calibration laboratories, improving comparability. It is suggested that in the non-invasive tube voltage measurement for mammography, practical peak voltage instead of average kilovolt peak should be used to reflect the measurement results.
Last Update: 2021-11-26