Ascending aortic aneurysms altered normal flow patterns on 4D-flow MRI, causing larger helices, prolonged retrograde flow, and increased average velocity (145 mm/s increase, P<0.001).
Observational (n=32)
Does 4D-flow MRI reveal differences in aortic flow patterns and velocities between patients with ascending aortic aneurysms and healthy volunteers?
4D-flow MRI demonstrates that ascending aortic aneurysms significantly alter normal hemodynamics, causing increased velocity, larger helices, and prolonged retrograde flow compared to healthy aortas.
Absolute Event Rate: 145% vs -47.9%
p-value: p=<0.001
PURPOSE: To determine the difference in flow patterns between healthy volunteers and ascending aortic aneurysm patients using time-resolved three-dimensional (3D) phase contrast magnetic resonance velocity (4D-flow) profiling. MATERIALS AND METHODS: 4D-flow was performed on 19 healthy volunteers and 13 patients with ascending aortic aneurysms. Vector fields placed on 2D planes were visually graded to analyze helical and retrograde flow patterns along the aortic arch. Quantitative analysis of the pulsatile flow was carried out on manually segmented planes. RESULTS: In volunteers, flow progressed as follows: an initial jet of blood skewed toward the anterior right wall of the ascending aorta is reflected posterolaterally toward the inner curvature creating opposing helices, a right-handed helix along the left wall and a left-handed helix along the right wall; retrograde flow occurred in all volunteers along the inner curvature between the location of the two helices. In the aneurysm patients, the helices were larger; retrograde flow occurred earlier and lasted longer. The average velocity decreased between the ascending aorta and the transverse aorta in volunteers (47.9 mm/second decrease, P = 0.023), while in aneurysm patients the velocity increased (145 mm/second increase, P < 0.001). CONCLUSION: Dilation of the ascending aorta skews normal flow in the ascending aorta, changing retrograde and helical flow patterns.
Hope et al. (2007) conducted an observational in Ascending aortic aneurysms (n=32). 4D-flow magnetic resonance velocity mapping vs. Healthy volunteers was evaluated on Average velocity change between the ascending aorta and the transverse aorta (p=<0.001). Ascending aortic aneurysms altered normal flow patterns on 4D-flow MRI, causing larger helices, prolonged retrograde flow, and increased average velocity (145 mm/s increase, P<0.001).