FIGURE 1.

In each multiplanar reconstruction image perpendicular to the automatically defined aortic centerline with a regular slice thickness of 1.2 to 1.7 mm, the contour of the aortic lumen was recognized and traced (i), and its length (A) was calculated. Simultaneously, diameters of the aortic luminal contour through the central luminal line were measured automatically for each individual degree (ii), and the mean value of 180 measurements of the diameters was computed (B, dotted line). Then, the ratio of A to the circumference of a perfect circle with a diameter of B (dotted circle) was determined [C = A/(3.14·B)]. The mean value of (C − 1) × 100 from the left subclavian artery ostium to the celiac artery ostium was calculated and defined as the shagginess score.