Abstract 13303: Improved Semi-Automated 4D Flow MRI Analysis in the Aorta in Patients With Congenitally Altered and Tricuspid Aortic Valves
Purpose: To systematically investigate a new semi-automated workflow for the analysis of aortic 4D flow MRI data. The ability to detect hemodynamic differences in patients with dilated aorta and congenitally altered aortic valve compared to tricuspid aortic valves was assessed.
Methods: ECG and respiration-synchronized 4D flow MRI data were acquired for 20 patients with aortic dilation (sinuses of valsalva (SOV) diameter>4cm). 9 patients had a tricuspid aortic valve (TAV, SOV dia=4.3±0.5cm, age=56±6) and 11 patients congenitally altered aortic valves (BAV) (SOV dia=4.2±0.6cm, age=47±9). 4D flow data were analyzed using a new semi-automated workflow including standardized 3D blood flow visualization and quantification of net flow, regurgitant fraction and peak systolic velocity in 4 analysis planes (root, mid-ascending aorta, mid-arch and descending aorta). Inter-observer variability, quantification accuracy, and the ability to detect hemodynamic differences between cohorts were compared to flow quantification based on manual segmentation of vessel contours (reference standard).
Results: Semi-automated 4D flow MR analysis reduced total processing time (40±16min) by 57%. Inter-observer agreement was good for all parameters (mean differences d<10% of average values). Good agreement was found for net flow and peak systolic velocity (d<8%) compared to the reference standard. Moderate agreement was found for regurgitation (d<41%). Significant differences in peak systolic velocities in the DAo (BAV: 1.0±0.2m/s, TAV: 0.8±0.1m/s, P=0.014) were detected between patient groups by both analysis methods.
Conclusion: 4D flow MRI-based analysis of aortic hemodynamics can be performed with good reproducibility and accuracy using a new faster and semi-automated workflow. Future prospective studies are warranted to investigate the integrating semi-automatic 4D flow analysis into the clinical workflow for the comprehensive evaluation of aortic disease.
- © 2013 by American Heart Association, Inc.