Quantification of epicardial adipose tissue in coronary calcium score and CT coronary angiography image data sets: Comparison of attenuation values, thickness and volumes

Objective: The aim of the study was to compare epicardial adipose tissue (EAT) characteristics assessed with coronary calcium score (CS) and CT coronary angiography (CTCA) image data sets.
Methods: In 76 patients (mean age 59613 years) who underwent CS and CTCA owing to suspected coronary artery disease (CAD), EAT was quantified in terms of density (Hounsfield units), thickness and volume. The EAT volume was extracted with a semi-automatic software.
Results: A moderate correlation was found between EAT density in CS and CTCA image data sets (2100619HU vs 270624 HU; p,0.05, r50.55). The distribution of EAT was not symmetrical with a maximal thickness at the right atrioventricular groove (14.265.3mm in CS, 15.765mm in CTCA; p.0.05, r50.76). The EAT volume resulted as 122650cm3 in CS and 86640cm3 in CTCA (D530%, p,0.05, r50.92). After adjustment for post-contrast EAT attenuation difference (D530 HU), the volume was 101647cm3 (D517%, p,0.05, r50.92). Based on EAT volume median values, no differences were found between groups with smaller and larger volumes in terms of Agatston score and CAD severity.
Conclusion: CS and CTCA image data sets may be equally employed for EAT assessment; however, an underestimation of volume is found with the latter acquisition even after post-contrast attenuation adjustment.