Article Details

Background: Computed tomography (CT) is widely used in emergency care due its speed, availability and diagnostic accuracy. However, reported radiation doses are not always representative of examinations performed under emergency indications, and dose is known to vary with protocols, organ exposed and clinical indication. Therefore, local assessment is required. Objective: To determine the radiation dose associated with brain CT examinations among patients referred from the accident and emergency unit of Aminu Kano Teaching Hospital, Kano. Methods: A cross sectional prospective study was conducted at the Muhammad Sanusi II Radio-diagnostic Centre, Aminu Kano Teaching Hospital. A data capture sheet was used to record tube potential (kVp), tube current time product (mAs), volume computed tomography dose index (CTDIvol), dose length product (DLP), scan length and pitch for 67 patients undergoing brain CT on a Toshiba Aquilion Prime 160 slice scanner with a maximum tube potential of 140 kVp. Effective dose was estimated by multiplying DLP by the head conversion coefficient of 0.0023 recommended by the European Union. Data were analyzed descriptively using SPSS version 23. Results: Of the 67 patients, 71.6% were male and 28.4% were female, with a mean age of 47.3 ± 19.1 years. CTDIvol ranged from 14.70 to 64.30 mGy (mean 60.76 ± 8.75 mGy), DLP ranged from 514.60 to 4919.40 mGy.cm (mean 1865.78 ± 665.43 mGy.cm), and effective dose ranged from 1.18 to 11.31 mSv (mean 4.29 ± 1.53 mSv). The 75th percentile values for CTDIvol, DLP and effective dose were 62.50 mGy, 2160.20 mGy.cm and 4.97 mSv respectively. Conclusion: The effective dose delivered to accident and emergency patients undergoing brain CT was higher than values reported by comparable national and international surveys, while CTDIvol values were broadly consistent with international recommendations. A protocol audit is recommended to optimize scan length and other exposure parameters in this unit.