Electron beam tomography imaging of coronary calcium: the effect of body mass index on radiologic noise.

Purpose: To measure selected parameters of radiologic noise in electron beam tomographic (EBT) images obtained for coronary artery calcium (CAC) screening, and to determine an association between the level of radiologic noise and patient body mass index (BMI).

Methods: Electron beam tomographic CAC studies were performed on 311 persons. The study sample was stratified into three groups according to subjects' BMI. Three regions of interest (ROI) parameters of radiologic noise were used to measure the strength of association between the level of radiologic noise and BMI.

Results: The measured ROI parameters of radiologic noise demonstrated a significant difference across the strata, with values gradually increasing from the normal weight group to the obese group. All ROI parameters showed significant correlations with BMI.

Conclusion: These findings support proposals to modify the current EBT CAC scoring methodology to account for variability in patient body size. These modifications may reduce the image noise levels and subsequently decrease the number of false-positive results.