Maximilian Russe MD, Presenter: Nothing to Disclose

Philipp Blanke MD, Abstract Co-Author: Nothing to Disclose

Benjamin Fritz MD, Abstract Co-Author: Nothing to Disclose

Gregor Pache MD, Abstract Co-Author: Nothing to Disclose

Wulf Euringer, Abstract Co-Author: Nothing to Disclose

Mathias F. J. Langer MD, PhD, Abstract Co-Author: Nothing to Disclose

Evaluation of alterations in flow pattern in the infrarenal aortic aneurysm using 4D flow MRI.

4D flow MRI was performed at 3T MR systems for a prospective study of eight male patients (age 70±9 years) with infrarenal aortic aneurysms. Flow quantification was performed using ECG gated three-directional velocity encoding with full 3D coverage of the abdominal aorta. 4D flow MRI was acquired in a coronar oblique 3D volume using flip angle of 15°, VENC: 80 cm/s, spatial resolution = (1.0-2,7)³mm³, and temporal resolution: 39-42 ms. Data analysis included 3D blood flow visualization (EnSight, CEI, USA) based on 3D particle traces and 3D streamlines. Time-resolved 2D data was extracted on plane based queries in the suprarenal abdominal aorta and in the AAA for each dataset; flow and wall parameters were derived: diameter, velocity, percentage of retrograde flow, wall shear stress (WSS) and oscillatory shear index (OSI).

Following changes were revealed between the abdominal aorta and the AAA. Decrease in mean velocity (aorta: 8.89 (±4.31) cm/s; AAA: 1.30 (±1.50) cm/s; -85%; p-value<0.01) Increase in percentage of retrograde flow (aorta: 8.1 (±13.2)%; AAA: 24.1 (±13.7)%; +197% p-value<0.01). Decrease in mean WSS (aorta: 116.2 (± 46.5) mN/m²; AAA: 23.6 (± 15.7) mN/m²; -80% p-value< 0.01) and increase in OSI (aorta: 7.2(± 4.0); AAA: 14.2(±8.4); +96%; p-value=0.13). The mean diameter was measured in the aorta with 21.4 (± 1.4) mm and in the AAA with 39.3 (± 8.9) mm (+84%, p<0.01).  

4D flow MRI demonstrates significant quantifiable hemodynamic changes in the infrarenal aortic aneurysm compared to the non-dilated suprarenal aorta. There is a decrease in mean velocity and an increase in percentage of retrograde flow, WSS and OSI. Follow-up studies are warranted to investigate the influence of these findings on progress of the aneurysm and patient outcome.

These findings in wall and flow parameters are additional quantifiable parameters in the abdominal aneurysms and may help for risk stratification and further therapy planning.

Russe, M, Blanke, P, Fritz, B, Pache, G, Euringer, W, Langer, M, Assessment of Blood Flow Patterns in Infrarenal Abdominal Aortic Aneurysms— An Approach using 4D Flow MRI.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010061.html