M . EL Fahssi et al .: Radioprotection 2024 , 59 ( 1 ), 13 – 18 17
dosimetric values recorded for brain CT scans require a review of the procedures and protocols for this type of examination at our hospital . In addition , the authors of this study have planned a study including several hospitals in the Souss Massa region to further study brain CT examinations .
For chest CT without contrast media , the calculated DRLs in terms of CTDIvol and DLP are 11,13 mGy , and 417,73 mGy . cm respectively . These values are lower than those reported by El Mansouri et al ., 2022 ( CTDI vol : 12,3 mGy ; DLP : 632 mGy . cm ), but they are higher than those reported in Saudi Arabia ( CTDI vol : 7 mGy ; DLP : 250 mGy . cm ), and the IRSN ( CTDI vol : 9,5 mGy ; DLP : 350 mGy . cm ). Variations in dosimetric values across different studies for chest CT-scans , may be accounted for differences in scan lengths , institutional preferred protocols , availability of dose reduction algorithms and age of scanners ( Arlany et al ., 2023 ).
The data from the abdominal CT show that the CTDI vol ( 9,74 mGy ) and DLP ( 529,31 mGy . cm ) values for abdomen CT with contrast media are higher than those without contrast media , which are ( 9,35 mGy ) and ( 515,21 mGy . cm ) respectively . Indeed , one of the objectives of using iodinated contrast media is to better adapt the higher voltage ranges of the X-ray tube , which would allow greater flexibility in scanning protocols and thus lead to techniques that can provide equivalent diagnostic value at lower radiation doses ( Schöckel et al ., 2020 ). However , the operators of the CT examinations in the site concerned in this study do not consider using contrast products to reduce kv and mAs and consequently , the dose delivered to patients .
DRls in terms of CTDI vol and DLP for AP with contrast media were 8,14 mGy and 444,51 mGy . cm respectively . These values are lower than those fixed by the IRSN ( CTDIvol : 13 mGy ; DLP : 625 mGy . cm ), and also lower than those reported in Saudi Arabia ( CTDIvol : 11 mGy ; DLP : 957 mGy . cm ). For CAP with contrast media , DRLs in terms of CTDIvol and DLP are 8,51 mGy , and 571,30 mGy . cm respectively . These values are lower than those fixed by the IRSN ( CTDIvol : 11 mGy ; DLP : 750 mGy . cm ).
The results of this study show a significant relationship between BMI and the effective dose for AP CT ( p = 0.000 ) and CAP CT ( p = 0.003 ), and the effective dose increases with BMI . For the same CT examinations , Chan et al . found that for every kilogram of weight , there is a 0.13 mSv increase in the effective dose , which is equal to 6.5 chest radiographs per CT examination ( Chan et al ., 2012 ).
In addition , the mean CTDI vol and DLP values for the chest , AP , and CAP were lower than those reported by Amaoui et al . and Semghouli et al . ( Amaoui et al ., 2019 ; Semghouli et al ., 2022b ). The last two studies were conducted at the same site as this study .
Reductions in CTDIvol and DLP will reduce the total collective dose to the population ( Dimitroukas et al ., 2022 ). In addition , it is possible to maintain the radiation dose at an optimum level by using a combination of CT protocol homogenization and optimization of radiation doses with an iterative process that maintains the image quality ( Rajiah , 2020 ), standardizing acquisition protocols , properly using dose reduction tools , examining and adjusting the acquisition parameters and image quality indices when abnormally high NRD values are observed ( Sebelego et al ., 2023 ), and improving education of practitioners in medical radiation protection ( Paulo et al ., 2020 ).
5 Conclusion
The results of this study showed that the dosimetric values for brain CT and chest CT were significantly higher than those reported in several previous studies . Therefore , it is necessary to review the protocols for performing this CT examination . Our results also show that the dosimetric values for the other CT examinations covered in this study are lower than those reported in similar studies .
Conflicts of Interest The authors declare no conflict of interest .
Funding This research did not receive any specific funding .
Ethical approval
This study received ethical approval from ethics committee for biomedical research , Mohammed V University of Rabat , under the protocol number 28 / 22 .
Informed consent
This article does not contain any studies involving human subjects .
Authors contributions
M . EL FAHSSI , S . SEMGHOULI , M . CAOUI : Conceptualization , Methodology , M . EL FAHSSI , S . SEMGHOULI , B . AMAOUI : Writing original draft . M . EL FAHSSI , S . SEMGHOULI , M . CAOUI : Visualization , Investigation . S . SEMGHOULI , M . CAOUI , L . JROUNDI : Supervision . M . EL FAHSSI , S . SEMGHOULI , M . CAOUI , L . JROUNDI , B . AMAOUI : Reviewing and Editing .
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