Estimates of Patient Doses and Kerma-Area Product Monitoring in Digital Radiography

Abstract

The application of the kerma-area product (PKA) meter is increased rapidly in dosimetry. This study presents measurements of PKA in adherence to the International Atomic Energy Agency protocol for 300 adult patients in digital radiographic procedures. Effective doses (ED) were calculated from PKA measurements and conversion coefficients (E-103/PKA) obtained from the International Commission on radiological protection 103. In skull posteroanterior (PA), skull lateral (LAT), cervical spine anteroposterior (AP), cervical spine LAT, chest PA, abdomen AP, lumbar spine AP, pelvis AP and lumbar spine LAT, the third-quartile PKA values were found to be 0.2, 0.28, 0.33, 0.19, 0.26, 0.95, 0.93, 0.96 and 3.15 Gycm2, and estimated mean EDs were 0.005, 0.008, 0.056, 0.021, 0.037, 0.146, 0.165, 0.097 and 0.258 mSv, respectively. The third-quartile PKA values were suggested as local diagnostic reference levels (LDRLs). Results were compared with the diagnostic reference levels (DRLs) of the UK, the European Commission, previously published LDRLs in Greece and China by Metaxas et al. and Zhang and Chu, respectively. The PKA (third-quartile) value for cervical spine AP was 120% higher than UK 2010 DRLs, lumbar spine LAT was 123% higher than LDRLs given by Metaxas et al. and chest PA was 160% higher than UK 2010 DRLs and 225% higher than Metaxas et al. provided LDRLs. The PKA results were lower than the UK, and two studies in Greece by Metaxas et al. except for chest PA, cervical spine AP and lumbar spine LAT showed the need for further optimization. The LDRLs reported in this study may further contribute to establishing future national DRLs.

Evaluation of patient doses for routine digital radiography procedures toward establishing an institutional diagnostic reference levels: A case study in Sri Lanka

“…The reported studies in India and Greece were conducted on a single DR system similar to the present study with 300 and 1504 patients,respectively. 16,17 The mean kVp values for most of the examinations were lower than the corresponding values for India and Greece. However, the mean mAs values were significantly higher than those used in India, except for the lumbar spine LAT examination.…”

“…Furthermore, the mean weight of this patient group was comparatively lower compared with the Greece (72 kg), 16 and India (65 kg). 17 The BMI values were also calculated for each patient using weight and height measurements (weight/(height) 2 ) obtained in this study. The BMI range (14.3-35.1 kg m −2 ) of the patients considered in this study is wider than the dosimetric surveys conducted in India (23.9-26.4 kg m −2 ) and Greece (24.8-25.3 kg m −2 ), and it provides a simple and useful classification scheme about the crude size and shape of the patients.…”

“…This could be explained by the higher mAs values used for skull PA (8.0 times) and LAT (6.5 times) examinations compared to the corresponding values in India. 17 The mean and 75th percentiles of the KAP distribution were compared with the LDRLs reported from Greece and India, as presented in Table 5. Dose measurements obtained on DR systems were used to establish the corresponding LDRLs in Greece and India.…”

“…Furthermore, dosimetric surveys conducted in certain countries revealed that there are wide variations in patient doses for the same X-ray examination even within the same institution. 16,17 These variations are mainly attributed to differences in patient size, clinical condition, competencies and experience of radiologic technologists, equipment conditions, and radiographic techniques utilized. 17,18 However, such variations should be minimized or prevented in good and normal practices, and further actions should be taken to optimize the doses.…”

“…16,17 These variations are mainly attributed to differences in patient size, clinical condition, competencies and experience of radiologic technologists, equipment conditions, and radiographic techniques utilized. 17,18 However, such variations should be minimized or prevented in good and normal practices, and further actions should be taken to optimize the doses. Therefore, DRLs are usually specified for standard-sized patients or phantoms for a specific X-ray examination but not for individual patients.…”