1. A method for imaging a magnetic resonance (MR) image by using a radio frequency (RF) multi-coil which includes a plurality of channel coils, the MR image generating method comprising: generating a plurality of pieces of K-space completion data which respectively correspond to the plurality of channel coils, and converting the plurality of pieces of K-space completion data to a frequency domain in order to generate a plurality of pieces of image data; acquiring the plurality of pieces of image data in order to acquire the MR image; and acquiring phase information which relates to the MR image based on at least one of first phase information, which is channel-specific phase information for a plurality of channels and acquired from the plurality of pieces of image data, and second phase information which is channel-specific phase information for a plurality of channels and acquired from the plurality of pieces of K-space completion data, wherein the generating a plurality of pieces of image data comprises, acquiring a plurality of pieces of K-space raw data which respectively correspond to the plurality of channel coils, and acquiring the plurality of pieces of K-space completion data by performing an auto-calibration on each of the acquired plurality of pieces of K-space raw data.