Surface Parameterization of an Abdominal Aortic Aneurysm to Characterize Geometrical Evolution During Longitudinal Study of Patients

For an abdominal aortic aneurysm (AAA) in vivo there are multiple tissues contacting its boundary, none of which have been fully considered for their effect throughout disease progression. Trends such as arterial asymmetry, surface curvature flattening, and arterial tortuosity could be significantly influenced by both surrounding tissue and hemodynamic factors. In order to quantify either the combined or separate influence of such factors during disease progression a precise characterization of aneurysm geometry evolution is needed. Multiple methods for geometrical parameterization of abdominal aortic aneurysms (AAAs) have been previously developed using isolated patient CT scan data but the focus has been mainly on the association of such geometrical parameters with the rupture risk and the efficacy of the parameterization is not fully investigated for a longitudinal study yet (multiple CT scans per patient at progressive intervals) [1]. For this study we have produced a series of 3D models for AAAs in longitudinal studies, developed an arterial centerline generation algorithm, and automated a geometric parameterization procedure for the arterial surfaces. It should be noted that the caliber of our collection of data is relatively rare as it is high resolution, features many patients, and on average has 4–5 images per patient.