Characterization of high-sensitivity metal oxide semiconductor field effect transistor dosimeters system and LiF:Mg,Cu,P thermoluminescence dosimeters for use in diagnostic radiology

Monitoring radiation exposure during diagnostic radiographic procedures has recently become an area of interest. In recent years, the LiF:Mg,Cu,P thermoluminescence dosimeter (TLD-100H) and the highly sensitive metal oxide semiconductor field effect transistor (MOSFET) dosimeter were introduced as good candidates for entrance skin dose measurements in diagnostic radiology. In the present study, the TLD-100H and the MOSFET dosimeters were evaluated for sensitivity, linearity, energy, angular dependence, and post-exposure response. Our results indicate that the TLD-100H dosimeter has excellent linearity within diagnostic energy ranges and its sensitivity variations were under 3% at tube potentials from 40 Vp to 125 kVp. Good linearity was also observed with the MOSFET dosimeter, but in low-dose regions the values are less reliable and were found to be a function of the tube potentials. Both dosimeters also presented predictable angular dependence in this study. Our findings suggest that the TLD-100H dosimeter is more appropriate for low-dose diagnostic procedures such as chest and skull projections. The MOSFET dosimeter system is valuable for entrance skin dose measurement with lumbar spine projections and certain fluoroscopic procedures. (C) 2002 Elsevier Science Ltd. All rights reserved.