The validity and reliability of the exposure index as a metric for estimating the radiation dose to the patient

Erenstein, H. G. (Department of Medical Imaging and Radiation Therapy, Hanze University of Applied Sciences, Groningen, Netherlands) ; Browne, D. (Tameside and Glossop Integrated Care Unit NHS Foundation Trust, United Kingdom) ; Curtin, S. (Directorate of Allied & Public Health, University of Salford, United Kingdom) ; Dwyer, R. S. (Department of Medical Imaging and Radiation Sciences, University of Johannesburg, South Africa) ; Higgins, R. N. (Directorate of Allied & Public Health, University of Salford, United Kingdom) ; Hommel, S. F. (Department of Medical Imaging and Radiation Therapy, Hanze University of Applied Sciences, Groningen, Netherlands) ; Menzinga, J. (Department of Medical Imaging and Radiation Therapy, Hanze University of Applied Sciences, Groningen, Netherlands) ; Pires Jorge, José A. (HESAV School of Health Sciences, HES-SO University of Applied Sciences and Arts Western Switzerland) ; Sauty, M. (HESAV School of Health Sciences, HES-SO University of Applied Sciences and Arts Western Switzerland) ; de Vries, G. (Department of Medical Imaging and Radiation Therapy, Inholland University of Applied Sciences, Haarlem, Netherlands) ; England, A. (Directorate of Allied & Public Health, University of Salford, United Kingdom)

Introduction With the introduction of digital radiography, the feedback between image quality and over-exposure has been partly lost which in some cases has led to a steady increase in dose. Over the years the introduction of exposure index (EI) has been used to resolve this phenomenon referred to as ‘dose creep’. Even though EI is often vendor specific it is always a related of the radiation exposure to the detector. Due to the nature of this relationship EI can also be used as a patient dose indicator, however this is not widely investigated in literature. Methods A total of 420 dose-area-product (DAP) and EI measurements were taken whilst varying kVp, mAs and body habitus on two different anthropomorphic phantoms (pelvis and chest). Using linear regression, the correlation between EI and DAP were examined. Additionally, two separate region of interest (ROI) placements/per phantom where examined in order to research any effect on EI. Results When dividing the data into subsets, a strong correlation between EI and DAP was shown with all R-squared values > 0.987. Comparison between the ROI placements showed a significant difference between EIs for both placements. Conclusion This research shows a clear relationship between EI and radiation dose which is dependent on a wide variety of factors such as ROI placement, body habitus. In addition, pathology and manufacturer specific EI’s are likely to be of influence as well. Implications for practice The combination of DAP and EI might be used as a patient dose indicator. However, the influencing factors as mentioned in the conclusion should be considered and examined before implementation.


Keywords:
Article Type:
scientifique
Faculty:
Santé
Branch:
Technique en radiologie médicale
School:
HESAV
Institute:
Unité de recherche en santé, HESAV
Date:
2020-10
Pagination:
6 p.
Published in:
Radiography
Numeration (vol. no.):
October 2020, vol. 26, suppl. 2, pp. S94-S99
DOI:
ISSN:
1078-8174
Appears in Collection:



 Record created 2020-10-02, last modified 2020-10-27

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