Introduction ‘Porcelain aorta’ is listed in the 2nd consensus document of the Valve Academic Research Consortium as a risk factor in aortic valve replacement. However, the extent of circumferential involvement is poorly defined with great variability in reported incidence. We present a simple, reproducible classification to describe the extent of aortic calcification and thus appropriately define ‘porcelain aorta’, aiding clinical decision-making and registry data collection.

Methods 175 consecutive CT aortograms were reviewed. The aorta was divided into 3 sections: with and each section ?divided into quadrants. These were individually scored using a 5-point scale (0 – no calcification, 5 – complete contiguous calcification). Results for each quadrant were summated for each segment to provide an indication of the distribution of calcification.

Results Only one patient (0.6%) had a ‘true’ porcelain aorta, defined as contiguous calcification across all quadrants at any aortic level. Intra- and inter-observer variation was excellent for the ascending aorta (K=0.85–0.88 and 0.81–0.96 respectively) whilst the inter-observer variation in the transverse arch was good at 0.75.

Conclusions Our data suggests the incidence of ‘true’ porcelain aorta may be significantly lower than reported in the literature. The predominance of calcification within the anterior wall of the proximal ascending aorta and the superior wall of the transverse arch may be clinically important. Application of this quick, simple and reproducible grading system, with no requirement for advanced software, may provide a tool to support accurate assessment of focal aortic calcification and its relationship to subsequent procedural risk.