Three-dimensional characterization of ascending aortic strain, motion and growth in patients undergoing thoracic endovascular aortic repair

Figures

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  Fig 1. Flow diagram outlining patient selection. dTAA, Descending thoracic aortic aneurysm; TBAD, type B aortic dissection; TEVAR, thoracic endovascular aortic repair.

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  Fig 2. The upper panel illustrates the step-by-step workflow for growth mapping (vascular deformation mapping-growth [VDM-G]), which begins with automated segmentation of two electrocardiography (ECG)-gated computed tomography angiograms (CTAs) (baseline scan and follow-up) acquired in diastole, followed by a multistep image registration process to compute aortic wall deformation over time (ie, growth).17 The lower panel outlines the workflow for quantifying three-dimensional (3D) pulsatile displacement (VDM-D), which begins similarly with segmentation of peak systole and peak diastolic phases, followed by a multistep image deformable registration process to quantify 3D displacement over the cardiac cycle.20 In both VDM techniques, the resulting data is visualized using a colorized map overlaid on the surface of a 3D aortic model by anatomic subregions.

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  Fig 3. Multi-level extraction of pulsatile cross-sectional area changes. Diastolic cross-sectional area (red) and systolic cross-sectional area (yellow/gray).

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  Fig 4. Mean ascending aortic shape, total displacement (color scale in mm) and aortic strain (mean and standard deviation) at three ascending levels for each subgroup: non-dilated, dilated, and thoracic endovascular aortic repair (TEVAR) groups.

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  Fig 5. Scatterplots between aortic strain post-thoracic endovascular aortic repair (TEVAR) and aortic growth. The upper scatterplot depicts the growth rate of the ascending aorta against the aortic strain measured at the midascending aorta (MA). The lower scatterplot depicts the growth rate of the native aortic arch against the aortic strain measured at the proximal arch (PA). The blue circles around points indicate a ascending aortic dilation (>40 mm).