Ursula Reiter, Presenter: Nothing to Disclose

Gert Reiter, Abstract Co-Author: Employee, Siemens AG

Gabor Kovacs MD, Abstract Co-Author: Nothing to Disclose

Aurelien F. Stalder, Abstract Co-Author: Employee, Siemens AG

Mehmet Akif Gulsun, Abstract Co-Author: Employee, Siemens AG

Andreas Greiser PhD, Abstract Co-Author: Employee, Siemens AG

Horst Olschewski MD, Abstract Co-Author: Nothing to Disclose

Michael Herbert Fuchsjaeger MD, Abstract Co-Author: Nothing to Disclose

To compare relative period of existence of vortical blood flow in the main pulmonary artery in patients with pulmonary hypertension (PH) from velocity vector field, streamline and particle trace visualization of time resolved three-dimensional (4D) magnetic resonance phase-contrast imaging (MR-PCI) data and to compare their linear relationship with invasively determined mean pulmonary arterial pressure (mPAP).

This prospective study was approved by the local ethical review board. 23 patients with manifest PH underwent right heart catheterization (RHC) and 4D MR-PCI of the main pulmonary artery. Blood flow patterns were visualized as 3D velocity vector fields projected on 2D anatomical images (3D-vector visualization), as 3D streamlines and as 3D particle traces and evaluated for period of existence of vortical blood flow (tvortex in percent of the cardiac interval) in the main pulmonary artery. Dependence of tvortex on visualization and relation to mPAP were analyzed by means of correlation, linear regression and Bland-Altman analysis.

tvortex derived from different visualizations strongly correlated (r = 0.94 for 3D-vector versus streamline and r = 0.92 for 3D-vector versus particle trace visualization). Bias and 95%-limits-of-agreement were -4% and ±14% for comparison 3D-vector versus streamline visualization and were -3% and ±15% for 3D-vector versus particle trace visualization. In all techniques tvortex showed strong correlation with mPAP with small standard errors from regression lines (r = 0.96, SE = 3.4 mmHg for 3D-vector, r = 0.95, SE = 3.6 mmHg for streamline, and r = 0.92, SE = 4.4 mmHg for particle trace visualization).

Although periods of existence of vortical blood flow determined from 3D-vector visualization correlated best with mPAP, visualization of streamlines and particle traces provide similar results.

4D velocity mapping represents an emerging tool in the analysis of PH hemodynamics and enables estimation of elevated mPAP irrespectively of flow visualization technique.

Reiter, U, Reiter, G, Kovacs, G, Stalder, A, Gulsun, M, Greiser, A, Olschewski, H, Fuchsjaeger, M, 4-Dimensional Magnetic Resonance Velocity Mapping Based Evaluation of Elevated Mean Pulmonary Arterial Pressure: Comparison of Vector, Streamline and Particle Trace Flow Visualization.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13024361.html