A simple and reliable tool to quantify calcium burden of ascending aorta

Background

Ascending aorta calcific plaques represent a potential source of emboli during open-heart procedures. The aim of our study was to validate a simple and new technique to quantify aorta calcium burden.

Methods

Ten thoracic CT scans (TCMD General Electric LightSpeed VCT 64 Slices) of octogenarian subjects were analysed by two radiologists and one vascular surgeon, using the Osirix Pro Software. A 3D reconstruction of the ascending thoracic aorta was obtained from the annular plane to the origin of the innominate trunk. The outer curvature maximal length was measured; therefore this value was divided by ten Region Of Interest (ROI) points. At each ROI an exact perpendicular section of the aorta was obtained, whose calcium involvement was expressed as a percentage. The overall calcium burden was expressed as the mean of the ten measurements.

Results

Cronbach test estimate was 0.975. Intraclass correlation coefficient (ICC) was 0.927 (95% confidence limits = 0.904-0.946) with F test = 39.3 and p < 0.001.

Conclusion

Our technique represents a simple and effective way to provide quantitative assessment of ascending aorta calcium burden. There is an excellent intra-observer congruity with high reproducibility of measurements. This method may be particularly useful when screening optimal candidates for transcatheter aortic valve implantation.