Patient-Specific In-vivo Dynamic Motion of Ascending Thoracic Aortic Aneurysms from Cine CTA

Ascending Thoracic Aortic Aneurysm (ATAA) is a potentially fatal cardiovascular condition that may result in dissection or rupture. As a general rule, current guidelines recommend surgical intervention when the aneurysm diameter exceeds a critical threshold, typically around 55 mm in average-risk patients. However, acute complications have been reported in patients with smaller aneurysms, underscoring the need for more accurate and individualised risk stratification criteria. In this work, we propose a novel method to extract the motion of the ATAA from Cine Computed Tomography Angiography cCTA data, enabling the derivation of multiple motion-related variables and the assessment of their clinical significance. This method involves a multi-view 2D U-Net segmentation, followed by an algorithm to calculate nodal deformation between independent segmentations at each time-step of the cardiac cycle. The motion is described generally across the ATAA and then specifically focused on the Aortic Root AR. The analysis was performed on 82 patients and, afterwards, a Principal Component Analysis PCA was performed on 28 metrics to understand which have a relevant impact on inter-patient variability. This showed that mean pressure, weight and centreline length are the most relevant variables to understand patient's variability considering PCA loadings. These results can offer new insights into ATAA biomechanics, supporting the development of future risk stratification models and clinical decision-making.