Using averaged models from 4D ultrasound strain imaging, circumferential strains in calcified areas of abdominal aortic aneurysms were 23.2% smaller than in non-calcified areas.
Observational (n=10)
No
Does the use of averaged models from 4D ultrasound strain imaging improve the differentiation of local wall strains in calcified regions of abdominal aortic aneurysms compared to single segmentations?
Averaged models from 4D ultrasound strain imaging reliably differentiate local elastic properties in abdominal aortic aneurysms, providing a potential new tool for assessing rupture risk beyond simple diameter measurements.
p-value: p=<0.05
Abdominal aortic aneurysms are a degenerative disease of the aorta associated with high mortality. To date, in vivo information to characterize the individual elastic properties of the aneurysm wall in terms of rupture risk is lacking. We have used time-resolved 3D ultrasound strain imaging to calculate spatially resolved in-plane strain distributions characterized by mean and local maximum strains, as well as indices of local variations in strains. Likewise, we here present a method to generate averaged models from multiple segmentations. Strains were then calculated for single segmentations and averaged models. After registration with aneurysm geometries based on CT-A imaging, local strains were divided into two groups with and without calcifications and compared. Geometry comparison from both imaging modalities showed good agreement with a root mean squared error of 1.22 ± 0.15 mm and Hausdorff Distance of 5.45 ± 1.56 mm (mean ± sd, respectively). Using averaged models, circumferential strains in areas with calcifications were 23.2 ± 11.7% (mean ± sd) smaller and significantly distinguishable at the 5% level from areas without calcifications. For single segmentations, this was possible only in 50% of cases. The areas without calcifications showed greater heterogeneity, larger maximum strains, and smaller strain ratios when computed by use of the averaged models. Using these averaged models, reliable conclusions can be made about the local elastic properties of individual aneurysm (and long-term observations of their change), rather than just group comparisons. This is an important prerequisite for clinical application and provides qualitatively new information about the change of an abdominal aortic aneurysm in the course of disease progression compared to the diameter criterion.
Hegner et al. (Wed,) conducted a observational in Abdominal aortic aneurysm (n=10). Averaged models from 4D ultrasound strain imaging vs. Single segmentations was evaluated on Difference in circumferential strains between areas with and without calcifications (p=<0.05). Using averaged models from 4D ultrasound strain imaging, circumferential strains in calcified areas of abdominal aortic aneurysms were 23.2% smaller than in non-calcified areas.