Calculation of left ventricle relative pressure distribution in MRI using acceleration data.
Measurements of pressure variations within the cardiac chambers could provide important information for clinical assessments of cardiovascular function. In this work an MRI method for evaluating spatial distributions of intracardiac relative pressure is presented. We first calculated pressure gradients from MR maps of blood acceleration by applying the NS equation. We then used an original algorithm to compute pressure distribution in a region of interest (ROI) by minimizing the pressure gradient curl so that the result in a given pixel is independent of the integration path. The method was assessed in five healthy volunteers by means of MR 2D maps of the blood acceleration in the left ventricle (LV) during ejection and filling phases. The pressure variations calculated from acceleration mapping fit the known physiological variations better than those based on velocity maps acquired in the same volunteers. Furthermore, the optimization algorithm presented here produced the same results as iterative algorithms proposed by other authors, but in much less time and without requiring adjustable parameters or boundary conditions.
Buyens
Fanny
F
Inserm, U494, University Pierre et Marie Curie, CHU Pitié-Salpêtrière, 91, bd de l'Hôpital, 75634 Paris Cedex 13, France. fanny.buyens@imed.jussieu.fr
Jolivet
Odile
O
De Cesare
Alain
A
Bittoun
Jacques
J
Herment
Alain
A
Tasu
Jean-Pierre
JP
Mousseaux
Elie
E
D000054:Acceleration; D000465:Algorithms; D001783:Blood Flow Velocity; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D016277:Ventricular Function, Left / Q000502:physiology*; D017725:Ventricular Pressure / Q000502:physiology*