The performance of a prototype device designed to evaluate quality parameters of radiological equipment: Complementary study

Abstract

Quality control measurements in radiological equipment are essential to verify their achievable performance standards, as average peak voltage (kVp), practical peak voltage (kVpp), exposure time, radiation dose and half-value layer (HVL). In a recent study, a multifunctional prototype's partial results were presented using a solid-state detector to evaluate quality parameters as kVp, exposure time and HVL of radiological equipment. In the present work, the accuracy of these measurements was improved, and dosimetric parameters were developed aiming to comply with normative requirements. The prototype board hardware was built with four sensors PIN RD100 A and a dedicated software based on their signals. In a single exposure, these signals were used in settled polynomial functions to determine kVp, kVpp, exposure time, radiation dose, dose rate and HVL. Characterization tests were undertaken at an instruments calibration laboratory and at a clinical research laboratory. A mathematical function was fitted for 50–120 kVp range, with R2 = 0.999. This new algorithm allowed improving the kVp accuracy from [0.3–2.3%] to [0.03–1.5%]. The reproducibility and accuracy of the radiation dose rate reached 0.94% and 0.34%, respectively. The dose range measurements varied from 0.01 to 40 mGy. In addition, calibration tests were performed in calibration laboratory at standard traceable radiation qualities of RQR6 and RQR8. The total uncertainty associated with this calibration did not exceed 2%. In conclusion, the prototype can be considered a multifunctional non-invasive instrument appropriate to evaluate radiological equipment performance with an effective range from 50 kV to 120 kV.