To evaluate the knowledge of CT technologists and radiographers concerning CT parameters, in order to keep CT users be aware of all CT parameters and their impact on image quality and patient dose while keeping their knowledge up to date.

This cross-sectional descriptive-analytic study was conducted in Zanjan province, Iran, using a valid and reliable online questionnaire with 53 questions distributed to 153 radiology personnel. Each questionnaire included questions about demographic characteristics and CT parameters, including kVp, mAs, image noise, slice thickness, pitch and automatic tube current modulation (ATCM), and the effects of these parameters on image quality and radiation dose.

A response rate of 61.0% (94/153) was achieved. This study enrolled 30 radiographers and 64 CT technologists. There was no significant difference in the mean scores of the two groups (52.16 ± 9.90 vs. 56.09 ± 12.00, t = -1.545, P= 0.126). CT personnel had the highest and lowest knowledge scores in image reconstruction (t = -28.33, P = 0.001) and mAs (t = 4.27, P = 0.590), respectively, whereas radiographers had the highest and lowest knowledge scores in the fields of image noise (t = 9.85, P = 0.015) and kVp (t = -12.73, P = 0.007), respectively.

The total knowledge scores of CT technologists and radiographers for various scan parameters affecting image quality and dose were insufficient. Thus, it is recommended that regular retraining courses be held to enhance and update technologists’ knowledge.