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Updated: Apr 29, 2026
In vitro Assessment of Aortic Regurgitation Using Four-Dimensional Flow Magnetic Resonance Imaging
Published on: February 25, 2022
Noninvasive pressure difference mapping derived from 4D flow MRI in patients with unrepaired and repaired aortic
Fabian Rengier1, Michael Delles1, Joachim Eichhorn1
11 University Hospital Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany ; 2 German Cancer Research Center (dkfz) Heidelberg, Department of Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany ; 3 Karlsruhe Institute of Technology (KIT), Department of Informatics, Institute for Anthropomatics and Robotics, Adenauerring 2, 76131 Karlsruhe, Germany ; 4 University Hospital Heidelberg, Department of Paediatric Cardiology, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany ; 5 Inselspital, University Hospital Bern, Institute for Diagnostic, Interventional and Pediatric Radiology (DIPR), Freiburgstr. 10, 3010 Bern, Switzerland.
Purpose:
To develop a method for computing and visualizing pressure differences derived from time-resolved velocity-encoded three-dimensional phase-contrast magnetic resonance imaging (4D flow MRI) and to compare pressure difference maps of patients with unrepaired and repaired aortic coarctation to young healthy volunteers.
Methods:
4D flow MRI data of four patients with aortic coarctation either before or after repair (mean age 17 years, age range 3-28, one female, three males) and four young healthy volunteers without history of cardiovascular disease (mean age 24 years, age range 20-27, one female, three males) was acquired using a 1.5-T clinical MR scanner. Image analysis was performed with in-house developed image processing software. Relative pressures were computed based on the Navier-Stokes equation.
Results:
A standardized method for intuitive visualization of pressure difference maps was developed and successfully applied to all included patients and volunteers. Young healthy volunteers exhibited smooth and regular distribution of relative pressures in the thoracic aorta at mid systole with very similar distribution in all analyzed volunteers. Patients demonstrated disturbed pressures compared to volunteers. Changes included a pressure drop at the aortic isthmus in all patients, increased relative pressures in the aortic arch in patients with residual narrowing after repair, and increased relative pressures in the descending aorta in a patient after patch aortoplasty.
Conclusions:
Pressure difference maps derived from 4D flow MRI can depict alterations of spatial pressure distribution in patients with repaired and unrepaired aortic coarctation. The technique might allow identifying pathophysiological conditions underlying complications after aortic coarctation repair.
