Radiation exposure of the head, midface and pelvis in multi-slice CT (MSCT):: Comparison with single-slice CT (SSCT)

Purpose: Comparison of the radiation exposure of the head, midface and pelvis in multi-slice CT (MSCT) and single-slice CT (SSCT) for manufacturer-implemented standard protocols. Materials and Methods: An anthropomorphic Alderson-Rando phantom equipped with LiF-thermoluminescent dosimeters in the head, neck and pelvic region was examined with different MSCT and SSCT protocols, and the measured organ doses were compared. Results: In comparison with the SSCT protocols, the MSCT protocols delivered about twice the organ dose to the head and pelvis and about eight times the organ dose to the midface. The comparison indicates that the parameters (slice collimation, mAs, pitch) used for the MSCT protocols deliver increased radiation doses. Conclusions: The current standard MSCT protocols generally lead to higher organ doses to the head, midface and pelvis than the SSCT protocols, raising the question whether using the MSCT protocols recommended by the manufacturer can be justified. The dose parameters should be optimized to achieve an acceptable balance of dose reduction and adequate image quality.