Comparison of incident air kerma (k_i) of common digital and analog radiology procedures in Kohgiluyeh and Boyer-Ahmad province

Introduction: Although in many developed countries, Analog radiography (AR) is replaced with digital radiography (DR) but AR is still widely used in many countries included Iran. Therefore, dosimetrically assessment of delivered dose is very important to avoid unnecessary patient dose.

Materials and Methods: In this study, all imaging centers in Kohgiluyeh and Boyer-Ahmad were selected. The initial information included the mean kVp and mAs used by the personnel to perform each radiological procedure were gathered through a questionnaire. Barracuda dosimeter was then used to measure Incident air kerma (k_i). Data obtained from digital radiography (DR) and analogue radiography (AR) were then analyzed and compared to each other.

Results: The mean incident air kerma (k_i) for five radiological procedures (chest AP&Lat, Skull AP&Lat, Lumbar spine AP&Lat, Thoracic spine AP&Lat and Pelvis) in digital devices were 0.38&1.34, 2.1&1.94, 4.99&7.83, 4.18& 6.41 and 4.33 mGy and those for analogue devices were 0.7&1.28, 3.05&3.02, 7.25&9.9, 7.125&8.36 and 5.36 mGy, respectively.

Discussion and Conclusion: The use of low kVp or high mAs is one of the reasons to increase the incident air kerma (k_i) in analogue methods comparing to digital methods in all procedures except the chest (in Lateral view). Also the results, surprisingly, showed that in some of the analogue methods incident air kerma (k_i) was less than digital methods which is most probably because of the auto-exposure conditions.