A questionnaire survey reviewing radiologists’ and clinical specialist radiographers’ knowledge of CT exposure parameters

OBJECTIVE: To review knowledge of computed tomography (CT) parameters and their influence on patient dose and image quality amongst a cohort of clinical specialist radiographers (CSRs) and examining radiologists. METHODS: A questionnaire survey was devised and distributed to a cohort of 65 examining radiologists attending the American Board of Radiology exam in Kentucky in November 2011. The questionnaire was later distributed by post to a matching cohort of Irish CT CSRs. Each questionnaire contained 40 questions concerning CT parameters and their influence on both patient dose and image quality. RESULTS: A response rate of 22 % (radiologists) and 32 % (CSRs) was achieved. No difference in mean scores was detected between either group (27.8 ± 4 vs 28.1 ± 4, P = 0.87) although large ranges were noted (18–36). Considerable variations in understanding of CT parameters was identified, especially regarding operation of automatic exposure control and the influence of kilovoltage and tube current on patient dose and image quality. Radiologists were unaware of recommended diagnostic reference levels. Both cohorts were concerned regarding CT doses in their departments. CONCLUSIONS: CT parameters were well understood by both groups. However, a number of deficiencies were noted which may have a considerable impact on patient doses and limit the potential for optimisation in clinical practice. KEY POINTS: • CT users must adapt parameters to optimise patient dose and image quality. • The influence of some parameters is not well understood. • A need for ongoing education in dose optimisation is identified.