Radiology. 2016 Jan 14:151078. [Epub ahead of print]
Mileto A1, Heye TJ1, Makar RA1, Hurwitz LM1, Marin D1, Boll DT1.
Purpose
To investigate the feasibility of deformable, motion-coherent modeling based on electrocardiography-gated multidetector computed tomographic (CT) angiography of the thoracic aorta and to evaluate whether quantifiable information on aortic wall stress as a function of patient-specific cardiovascular parameters can be gained.
Materials and Methods
For this institutional review board-approved, HIPAA-compliant study, thoracic electrocardiography-gated dual-source multidetector CT angiographic images were used from 250 prospectively enrolled patients (150 men, 100 women; mean age, 79 years). On reconstructed 50-phase CT angiographic images, aortic strain and deformation were determined at seven cardiac and aortic locations. One-way analysis of variance was used by assessing the magnitude for longitudinal and axial strain and axial deformation, as well as time-resolved peak and maxima count for longitudinal strain and axial deformation. Interdependencies between aortic strain and deformation with extracted hemodynamic parameters were evaluated.
Results
With increasing heart rates, there was a significant decrease in longitudinal strain (P = .009, R2 = 0.95) and a decrease in the number of longitudinal strain peaks (P < .001, R2 = 0.79); however, a significant increase in axial deformation (P < .001, R2 = 0.31) and axial strain (P = .009, R2 = 0.61) was observed. Increasing aortic blood velocity led to increased longitudinal strain (P = .018, R2 = 0.42) and longitudinal strain peak counts (P = .011, R2 = 0.48). Pronounced motion in the longitudinal direction limited motion in the axial plane (P < .019, R2 = 0.29-0.31).
Conclusion
The results of this study render a clinical basis and provide proof of principle for the use of deformable, motion-coherent modeling to provide quantitative information on physiological motion of the aorta under various hemodynamic circumstances. © RSNA, 2016 Online supplemental material is available for this article.