Reducing emergency CT radiation doses with simple techniques: A quality initiative project.

Introduction: Use of indication-specific CT protocols and adjustment of scan parameters to decrease radiation exposure may result in significant dose reduction. We implemented these strategies and compare pre- and post-implementation radiation dose in emergency department (ED) patients.

Method: This was a descriptive, retrospective study. Patients older than 15 years who had undergone emergency CT examinations of the head, chest, abdomen, pelvis and abdominopelvic region in periods before and after dose-reduction implementation were included. The primary outcome was volume CT dose index (CTDIvol ) and dose length products (DLP).

Results: There were 786 studies in the pre-implementation (group 1) and 955 studies in the post-implementation (group 2) periods. Radiation dose from all CT types significantly reduced in the post-implementation period. Average CTDIvol for head, chest, abdomen, pelvis and abdominopelvic region (doses during pre-implementation period in parentheses) were 51.5 (109), 8.1 (30.4), 13.1 (41.8), 11 (38), 11.2 (41.8) mGy, respectively. Average DLP was also significantly lower (pre-implementation dose in parentheses) in all CT types, which were 943 (2232), 324 (2517), 944 (5605), 280 (4024), 809 (7118) mGy●cm, respectively. Patients' age, gender, body mass index and size were not significantly different between the two groups. Image quality decreased but almost all examinations received an acceptable diagnostic subjective image quality.

Conclusion: Simple methods could help significantly reduce CT radiation exposure in ED patients while maintaining an acceptable level of diagnostic image quality.