Quantification of Particle Residence Time in Abdominal Aortic Aneurysms Using Magnetic Resonance Imaging and Computational Fluid Dynamics

• Published in: Annals of biomedical engineering Vol. 39; no. 2; pp. 864 - 883
• Main Authors: Suh, Ga-Young, Les, Andrea S, Tenforde, Adam S, Shadden, Shawn C, Spilker, Ryan L, Yeung, Janice J, Cheng, Christopher P, Herfkens, Robert J, Dalman, Ronald L, Taylor, Charles A
• Format: Journal Article
• Language: English
• Published: Boston Boston : Springer US 01.02.2011; Springer US; Springer Nature B.V
• Subjects: Aged; Aged, 80 and over; Aneurysm geometry; Aortic Aneurysm, Abdominal - physiopathology; Biochemistry; Biological and Medical Physics; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Biomedicine; Biophysics; Blood Flow Velocity; Boundary conditions; Classical Mechanics; Computer Simulation; Flow stagnation; Flow waveforms; Fluid dynamics; Gadolinium; hemodynamics; Humans; Hydrodynamics; Magnetic Resonance Angiography - methods; Male; Middle Aged; Models, Cardiovascular; Particle clearance; Particle Size; Pulsatile flow simulation; Subject-specific; Vascular diseases; Flow stagnation; Aneurysm geometry; Pulsatile flow simulation; Particle clearance; Hemodynamics; Subject-specific; Flow waveforms
• ISSN: 0090-6964; 1573-9686; 1573-9686; 1521-6047
• DOI: 10.1007/s10439-010-0202-4

Hemodynamic conditions are hypothesized to affect the initiation, growth, and rupture of abdominal aortic aneurysms (AAAs), a vascular disease characterized by progressive wall degradation and enlargement of the abdominal aorta. This study aims to use magnetic resonance imaging (MRI) and computational fluid dynamics (CFD) to quantify flow stagnation and recirculation in eight AAAs by computing particle residence time (PRT). Specifically, we used gadolinium-enhanced MR angiography to obtain images of the vessel lumens, which were used to generate subject-specific models. We also used phase-contrast MRI to measure blood flow at supraceliac and infrarenal locations to prescribe physiologic boundary conditions. CFD was used to simulate pulsatile flow, and PRT, particle residence index, and particle half-life of PRT in the aneurysms were computed. We observed significant regional differences of PRT in the aneurysms with localized patterns that differed depending on aneurysm geometry and infrarenal flow. A bulbous aneurysm with the lowest mean infrarenal flow demonstrated the slowest particle clearance. In addition, improvements in particle clearance were observed with increase of mean infrarenal flow. We postulate that augmentation of mean infrarenal flow during exercise may reduce chronic flow stasis that may influence mural thrombus burden, degradation of the vessel wall, and aneurysm growth.