Flow-sensitive four-dimensional magnetic resonance imaging: flow patterns in ascending aortic aneurysms

Area of Science:

• Cardiovascular Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Pathological aortic flow patterns significantly differ from healthy hemodynamics.
• The development and impact of pathological flow in thoracic aortic diseases are largely unknown.
• Altered flow may influence disease pathogenesis and progression.

Purpose of the Study:

• To present pathological blood-flow patterns in patients with ascending aortic aneurysms.
• To investigate the impact of aneurysms on aortic hemodynamics.
• To compare flow patterns in aneurysms to healthy individuals.

Main Methods:

• Utilized flow-sensitive 4D Magnetic Resonance Imaging (MRI) on a 3T system.
• Employed 3D computer-aided flow visualization (streamlines, particle traces).
• Investigated six adult patients with ascending aortic aneurysms and one healthy control.

Main Results:

• Healthy aorta showed helical flow (0.5-1.5 revolutions) with velocities up to 1 m/s.
• Atherosclerotic aneurysms exhibited increased helical flow or multiple vortical flows.
• Marfan-associated and pseudo-aneurysms showed increased vortical flow; bicuspid aortic valve aneurysm had a major vortex above the valve.

Conclusions:

• Ascending aortic aneurysms present diverse local flow patterns compared to healthy individuals.
• Significant variations in flow patterns exist among patients with aneurysms.
• Further research is needed to link specific flow patterns to aneurysm development and adverse events.