The present invention includes a computerized method of detecting fluid flow in a vessel, the method comprising: obtaining at least one non-contrast enhanced magnetic resonance image from a magnetic resonance imager； performing a phase sensitive reconstruction of the at least one non-contrast enhanced magnetic resonance image using a processor； combining the phase sensitive reconstruction with a velocity selective preparation of the non-contrast enhanced magnetic resonance image, to determine using the processor, in a single acquisition, at least one of: a flow direction of a fluid in the vessel, a reduction or elimination of a background signal, body fat, water/fat separation, or differentiation of a fast moving flow signal from a slow moving flow signal in an opposite direction with suppression of the background signal； and storing or displaying at least one of flow direction or flow strength of the fluid flow in the vessel obtained from the single acquisition.
