Diagnostic reference levels for adult’s abdominal computed tomography in a referral centre in Nigeria

Abstract

To address the limitation of CTDIvol, the American Association of Physicists in Medicine recently published a report on SSDE in body CT, where a patient’s size is used to compute an estimate of patient dose from CTDIvol. This study estimates patients’ radiation dose in abdominal computed tomography examination by considering patient size and established a facility diagnostic reference levels (DRLs) based on CTDI, DLP and SSDE for the purpose of dose optimization. A prospective cross-sectional study was carried out at Aminu Kano Teaching Hospital (AKTH), Kano-Northwestern Nigeria from April 2019 to September 2019. The study reviewed Fifty-five patients for abdominal Computed Tomography based on the recommendation of ICRP for DRLs. The study considered CTDIvol, DLP and SSDE. The SSDE is based on the anterior-posterior and lateral diameters of the patients; and a conversion factor (f). Statistical Package for Social Sciences (SPSS) Version 23.0 was used to analysed the mean, median, standard deviation and interquartile range of the radiation dose received. Independent Student t-test was used to determine the relationship between CTDIvol, DLP and SSDE by taking SSDE as an independent variable. The mean and standard deviation values of the estimated SSDE for 18-27, 28-37, 38-47, 48-57, 58-67 and 68-77 patients’ age groups are 12.9, 13.74, 13.22, 13.49, 10.44 and 12.43mGy and 4.15, 5.71, 5.21, 4.05, 3.14 and 5.24 respectively. The established DRL values for CTDI, DLP and SSDE are 11.50, 620.30 and 16.85 respectively. There was no statistical significance difference (P<0.05) between reported CTDI and DLP and the estimated SSDE. There is good optimization of radiation dose in Aminu Kano teaching hospital, with regard to CT abdomen but still patients’ size needs to be considered.