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 des cribed and an example of its application given in the context of veloc ity phase-encoded MRI of blood flow in the aorta. The method takes as its starting point Zernike's technique of phase contrast microscopy. I t 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. T he method then effectively combines phase and magnitude information in to a single image. The technique is complementary to existing methods of displaying phase information.