Head computed tomography: Dose output and relationship with anthropotechnical parameters

Background: The number of computed tomography (CT) centers and examinations in Nigeria has shown a steady increase. This will increase the collective dose and may potentially result in an increased incidence of cancer, hereditary diseases, and the possibility of mild deterministic effects. Objective: To determine radiation dose output and its relationship with anthropotechnical parameters. Methodology: A retrospective analyses of digital CT files. Effective dose was derived from the dose-length product and factor for examination of head CT (0.0023 mSv/mGy-cm). SPSS version 20.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the data. Results: Files of 43 male and 42 female (n = 85) adult patients were analyzed. The mean (and 75 th percentile) of the CT dose index (CTDI), dose-length product (DLP), and effective dose in noncontrast examinations were 48 (59) mGy, 874 (1301) mGy-cm, and 1.8 (2.7) mSv, respectively. Contrast examinations yielded 54 (61) mGy, 1476 (2044) mGy-cm, and 3.1 (4.3) mSv, respectively. DLP showed a weak relationship with BPD (r = −0.220), age (r = 0.211), cephalic index (r = −0.186), height (r = 0.158), and gantry tilt (r = 0.154). There was no relationship with weight (r = 0.076), range (r = −0.073), occipitofrontal diameter (r = 0.037), and body mass index (r = −0.018). The correlations were neither statistically nor clinically significant. Conclusion: The CTDI is comparable with local values while the DLP is lower by a range of 5-31% but higher than foreign values by a range of 19-35%. Further optimization of CT radiation dose should be explored to eliminate the gulf between local and foreign dose outputs.