Calculation of the aortic arch angles from three-dimensional reconstructions of computed tomography scans: Comparison between an automated program and visual assessment. (November 2019) - Gaudric, Julien
Abstract: Background: The curvature of the aortic arch is associated with the risk of endoleak formation after thoracic endovascular aortic repair (TEVAR). However, the adequate assessment of the angles of the aorta continues to represent a major difficulty. We developed a new program based on three-dimensional (3D) reconstructions of computed tomography (CT) scans to objectively identify the location of the aortic points of maximum curvature, and to automatically calculate the main aortic arch angles, comparing final values with visual assessment methods. Methods: This is a cross-sectional validation study of a convenience sample of subjects with multislice CT angiography scans of the thoracic aorta from an institutional imaging database. The center lumen line (CLL) of the aorta was determined semi-automatically using Endosize software. The points of maximum curvature on the CLL were determined by two methods: visually by two physicians and through a custom program. Results: The study enrolled 9 subjects: 4 with thoracic aneurysms and 5 with normal aortas. The inter-observer and inter-method correlation, agreement and reliability for each of the 3D spatial coordinates of the points of maximum curvature were appropriate. However, the aortic angles determined by visual assessment showed a very low to moderate correlation and reliability with those determined by our custom program. Conclusion: An automated custom program can reflect clinician's intuitive assessment of the location of points of maximum curvature and translate it into aortic angles with an apparently higher precision, reducing potential error and user time. Graphical abstract: Image 1 Highlights: Aortic points of maximum curvature can be identified by an automated program. High correlation between aortic points measured by program and visual assessment. Aortic angles can be calculated from the aortic points of maximum curvature. Poor correlation between aortic angles measured by program and visual assessment. Possible higher precision with program, being more objective and reproducible.