‘Porcelain aorta’: a proposed definition and classification of ascending aortic calcification

Figures

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  Figure 1. (A) Sagittal section through the thoracic aorta demonstrating division of the ascending aorta from the sinotubular junction to the origin of the left subclavian artery (blue arrow) into three segments. (B) Axial section through the ascending aorta at the level of the right pulmonary artery demonstrating division of the ascending aorta (segments 1 and 2) into four quadrants (anterior (a), posterior (p), right (r) and left (l)). (C) Coronal reformat at the level of the left subclavian artery origin (blue arrow) demonstrating division into right (r), left (l), superior (s), inferior (i) quadrants. (D) Axial section through the ascending aorta at the level of the left pulmonary artery (segment 2) demonstrating calcification extending across just over 50% of the posterior segment (assigned a score of 3: 50%–74% involvement). No calcification is demonstrated in the other quadrants at this level.

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  Figure 2. A truly ‘porcelain aorta’. Coronal (A) and axial (B) CT reconstructions demonstrate confluent, circumferential calcification extending from the sinuses of Valsalva to the distal transverse aortic arch. The full extent of calcification is well demonstrated on volume-rendered tomograms (C and D) with further, less confluent, involvement of the proximal descending aorta.

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  Figure 3. Focal calcification at the borders between segments impacts on reproducibility. This is particularly relevant in segment 3 (between the red lines), where calcification both proximal and distal to the segment boundaries may be included (arrows), likely explaining poorer interobserver and intraobserver variability in this segment.

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  Figure 4. Extent and distribution of calcification in the ascending aorta/arch by location, normalised by dividing quadrant totals by segment length. (Segment 3 represents proximal aortic arch and therefore quadrant orientation changes, eg, anterior quadrant becomes superior quadrant.) Mean absolute values are calculated by averaging axial image scores for each quadrant within each segment. Maximum score of 5 (segment 1: sinotubular junction (STJ) to mid-way to the origin of the innominate artery; segment 2: from midpoint to the origin of the innominate artery; segment 3: origin of the innominate artery to the origin of the left subclavian artery (LSCA)).