Does Height Matter? The Effect of Operator Height on Exposure Level in the Interventional Suite

Purpose: To demonstrate the relationship between operator height and annual occupational dose equivalents of interventional radiologists.

Methods/Materials: Dosimeter data was obtained for fellow (n=49) and attending (n=8) interventional radiologists at an academic hospital from June 2012 to June 2022 (academic years 2012-2021). Twelve-month averages of monthly deep dose equivalents were compared to self-reported heights of each operator and analyzed by academic year using multivariate ordinary least squares (OLS) and t-statistics. Regression slope parameter estimates (rads/inch) were used to demonstrate the strength of correlation between operator height and occupational dose.

Results: Multivariate OLS regression showed that operator height (fellow [p < 0.001], attending [p < 0.012]) and academic-year (fellow [p < 0.001], attending [p < 0.001]) explained significant components of yearly average procedure radiation exposure variability. Overall, multivariate regression model explained 65% (R2 =0.65, p< 0.001) of fellow and 60% (R2 =0.60, p< 0.001) of attending variability in yearly average radiation exposure over the academic years 2012-2021.
Regression slope parameter estimates of fellow physician yearly average procedure radiation exposure was negative for academic years 2012-2018 and lost statistical significance for academic years 2019-2020; for academic year 2021, it was positive and not significant (Figure A). For attending physicians, the negative relationship was significant for academic years 2012-2019 and not significant from academic years 2020-2021 (Figure B).

Conclusions: The majority of years analyzed in this study demonstrate a significant negative correlation between operator height and annual occupational dose equivalents, implying shorter operators receive higher radiation exposure. This relationship depended on the year of data collection, with the strength of negative correlation steadily decreasing for both fellow and attending physicians through the observation years. These results possibly suggest that advancements in safety equipment and improved operator awareness are decreasing disparity of occupational exposure between taller and shorter operators.