Abstract
Thoracic aortic aneurysm is a common and lethal disease that requires regular imaging surveillance to determine timing of surgical repair and prevent major complications such as rupture. Current cross-sectional imaging surveillance techniques, largely based on computed tomography angiography, are focused on measurement of maximal aortic diameter, although this approach is limited to fixed anatomic positions and is prone to significant measurement error. Here we present preliminary results showing the feasibility of a novel technique for assessing change in aortic dimensions, termed vascular deformation mapping (VDM). This technique allows quantification of 3-dimensional changes in the aortic wall geometry through nonrigid coregistration of computed tomography angiography images and spatial Jacobian analysis of aortic deformation. Through several illustrative cases we demonstrate that this method can be used to measure changes in the aortic wall geometry among patients with stable and enlarging thoracic aortic aneurysm and dissection. Furthermore, VDM results yield observations about the presence, distribution, and rate of aortic wall deformation that are not apparent by routine clinical evaluation. Finally, we show the feasibility of superposing patient-specific VDM results on a 3-dimensional aortic model using color 3D printing and discuss future directions and potential applications for the VDM technique.
Highlights
The thoracic aorta is the largest blood vessel in the human body and is subject to most extreme hemodynamic forces
The aortic arch and descending aorta were not included in the initial surgical repair given the mild degree of preoperative dilation; the distal arch and descending aorta were noted to progressively enlarge over 3 subsequent computed tomography angiography (CTA) examinations spanning a period of 3.8 years (Figure 2)
The clinical radiologist’s assessment using maximal aortic diameters identified enlargement at each interval, the growth rate appeared to be decelerating by diameter measurements, and the growth was reported to be limited to the distal arch, whereas the vascular deformation mapping (VDM) clearly highlighted more extensive enlargement along the length of the aorta, involving the proximal and mid-descending aorta at the second and third intervals
Summary
The thoracic aorta is the largest blood vessel in the human body and is subject to most extreme hemodynamic forces. Aortic dissection is a related form of aortic disease characterized by tearing of the inner layers of the aortic wall (ie, intima and media), leading to the creation of a false lumen— or channel—within the aortic wall itself, which is structurally compromised and is subjected to high pressures. This results in aneurysm formation in ϳ60% of patients with chronic aortic dissection of the descending thoracic aorta (Stanford type B) [2]. Recent data suggest that the prevalence of thoracic aortic dilation (Ͼ4 cm) is ϳ3% of individuals older than 55 years of age, which, on the basis of current US population estimates, means that ϳ2.7 million people in the USA would be recommended to undergo regular imaging of the thoracic aorta on the basis of the current American Heart Association guidelines for imaging surveillance [4,5,6,7,8]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
