J. Bazoma et al.: Radioprotection 2026, 61( 2), 105 – 112 111
( E = 8.2 mSv)( Etim Ekpo, 2018), in the USA( E = 5.9 mSv)( Gao, 2020), and in Iran( E = 3.7 mSv)( Khoramian, 2017).
For AP scan, the stomach dose( 4.3 mGy), the liver dose( 4.2 mGy) and the colon dose( 4.9 mGy) determined in this study are lower than those determined in Iran( stomach dose = 9.4 mGy, liver dose = 9.2 mGy)( Khoramian, 2017), and in the USA( stomach dose = 13.1 mGy, liver dose = 17.5 mGy, colon dose = 16.0 mGy)( Gao, 2020). The effective dose( E = 2.2 mSv) associated with AP scan is lower than the value determined in Iran( E = 7.4 mSv)( Khoramian, 2017), and in the USA( E = 8.7 mSv)( Gao, 2020).
Regarding CAP scan, the stomach dose( 4.5 mGy), the liver dose( 4.3 mGy) and the colon dose( 4.9 mGy) determined in this study are lower than those determined in the USA( stomach dose = 15.8 mGy, liver dose = 19.0 mGy, colon dose = 16.3 mGy)( Gao, 2020). The effective dose( E = 2.4 mSv) associated with CAP scan is lower than the value determined in the USA( E = 12.8 mSv)( Gao, 2020).
It is clear that organ and effective doses determined in this study are significantly lower than those reported in the selected studies reported in the literature. This may be due to the fact that this study involved only one CT installation while the selected studies involved several installations with different CT machines and imaging protocols. This study also showed that the CAP and AP scans are associated with the highest effective dose while the head scan is associated with the lowest effective dose.
3.8 Image quality
Application of DRLs is not sufficient for optimization of protection. The diagnostic quality of the corresponding images must also be evaluated( ICRP, 2017). However, it was not possible to evaluate image quality with a normalized protocol. This could be evaluated in a future study.
Conflicts of interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Data availability statement
Research data are stored in our institutional repositories and could be shared upon request.
Author contribution statement
J. Bazoma: Writing- original draft, Data collection, Methodology, Conceptualization. G. B. Dallou: Writing- review & editing, Methodology, Conceptualization. P. Ondo Meye: Writing- review & editing, Methodology, Conceptualization. R. N. Nzambi Mfoutou: Review & editing, Methodology, Conceptualization. R. R. C. Moubakou Diahou: Review & editing, Methodology, Conceptualization. F. R. Moyikoua: Review & editing, Methodology, Conceptualization. C. Bouka Biona: Review & editing, Methodology, Conceptualization.
Ethics approval
All data were handled in agreements with the research authorization No. 0378 / MSP-CAB / DGAR / DARH / SFS-24 granted by the Ministry of health and population, Republic of Congo, and the research authorization No. 044 / MSP / CHUB-DG / DERE / SR-23 granted by the General Directorate of the university hospital of Brazzaville. Informed consent
As a retrospective study, the institutional review boards of the university hospital judged that this research work did not need to obtain patient informed consent.
4 Conclusion
The present paper aimed to assess typical values, size specific dose estimates, organ doses and effective doses of adult patients undergoing CT examinations in a university hospital in Brazzaville, Congo Republic. Overall, a significant variation of the mAs, CTDI vol and DLP collected was observed. Typical values, size specific dose estimates, organ doses and effective doses were computed. For Typical DRL values and SSDE values, it was observed that the values for female patients were not statistically different from those for male patient, globally. The overall dose values determined in this study were clearly lower than those reported in selected studies reported in the literature. The study also showed that the CAP and AP scans were associated with the highest effective dose while the head scan was associated with the lowest effective dose.
Funding
This work has received operational support from Marien Ngouabi university and from the National Research Institute in Exact and Natural Sciences, Republic of Congo.
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