Joseph Dlama Zira, Christian Chukwuemeka Nzotta, Joseph Dimas Skam


Background: Diagnostic reference levels (DRLs) for computed tomography (CT) examination is important for dose optimization. The are suggested action levels and reference guide for achieving radiation protection among patients.

Objective of the study: To establish DRL for CT examination in north eastern Nigeria and to compare it with other established work.

Methodology: Prospective cross-sectional study conducted in two hospitals in north eastern Nigeria. One hundred and eighty subjects were recruited for the study. Computed tomography dose index (CTDI vol), dose length product (DLP) and Scan parameters were obtained. Weight, height and body mass index (BMI) were recorded. Student T-test was used to compare the relationship between the mean CTDIvol obtained in the two centers, Pearson’s correlation was used to determine the relationship between the dosimetric and anthropotechnical parameters. Statistical significance was set at P<0.05.

Results: The DRL values obtained in this work were 67.90 mGy, 18.83 mGy and 19.20 mGy for head CT, Chest CT and CT abdomen respectively. There was no statistical significant relationship (p>0.05) between CTDIvol with thickness, weight, height and BMI for head CT and abdominal CT. However, CTDI for Chest CT show statistical significant relationship (p<0.05) with weight and height.

Conclusion: DRL was higher when compared with international values. There is need for optimization of radiology practice in North Eastern Nigeria.

Key words: X-rays, computed tomography, diagnostic reference levels, CTDIvol, dose length product, dose, optimization.

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