A novel spiral phase contrast (PC) technique was developed for high temporal resolution imaging of blood flow without cardiac gating. An autocalibrated spiral sensitivity encoding (SENSE) method is introduced and used to reconstruct PC images. Numerical simulations and a flow phantom study were performed to validate the technique. To study the accuracy of the flow measurement in vivo, a high-resolution cardiac experiment was performed and a subset of undersampled SENSE reconstructed data were reconstructed. Good agreement between the velocity measurement from the fully-sampled and undersampled data was achieved. Real-time experiments were performed to measure blood velocity in the ascending aorta and aortic valve, and during a Valsalva maneuver. The results demonstrate the potential of this technique for real-time flow imaging.