Application of the principle of optical phase-contrast microscopy to velocity phase-encoded MRI of blood flow in the aorta

A new method of presenting magnetic resonance phase information is described and an example of its application given in the context of velocity phase-encoded MRI of blood flow in the aorta. The method takes as its starting point Zernike's technique of phase contrast microscopy. It exploits the parallel between the transform plane in Fourier optics and k-space in MRI. In the example described two datasets are acquired, one with and the other without velocity encoding as in conventional phase-encoded velocity imaging. A dataset is formed which is corrected for unwanted phase variations caused by static field inhomogeneity. The method then effectively combines phase and magnitude information into a single image. The technique is complementary to existing methods of displaying phase information.