Untitled

Abstract

In medical imaging, Computed Tomography (CT) scan examination is a major source of ionizing radiation. All medical radiological exposures should be justified and optimized to meet up with the needed clinical outcome. Therefore, to avoid unnecessary radiation doses to patients, Diagnostic Reference Levels (DRLs) for CT examinations should be adhered to. The DRLs are used to identify radiation dose outliers during CT scan examinations, which does not contribute to good clinical diagnosis. DRLs have been successfully implemented in the UK, Australia, Japan, Canada and United States of America; and a few underdeveloped countries. The present study aimed at assessment of patients' radiation dose during chest CT scan examination with a view to establishing local diagnostic levels in Rivers State, South-South, Nigeria. Sixty (60) adult patients comprising of 20 patients from center A, 20 patients from center B, and 20 patients from centre C were purposively sampled. The patients aged between 16-100 years and weighed 70±10 kg. The prospective data collection spans four months, and CTDIv and DLP were retrieved after each CT scan examination. SPSS version 25.0 was used to analyze data. Mean CTDIv and DLP values were calculated and their 75 th percentile value was obtained as the DRL for anatomical region studied. DRLs proposed for chest CT examinations for Rivers state were: 10.6 mGy and 414.70 mGy.cm for CTDIv and DLP respectively. These values are lower than the European Commission DRLs and comparable to other international studies. Wide variation in mean doses are noted across the region. Therefore, the chest CT examination practice within the region is optimized.