1. A magnetic resonance (MR) image generating method for acquiring an 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; combining 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 a plurality of pieces of first phase information and a plurality of pieces of second phase information, wherein each of the plurality of pieces of first phase information is channel-specific, and is acquired from and corresponds to a respective one of the plurality of pieces of image data, and wherein each of the plurality of pieces of second phase information is channel-specific, and is acquired from and corresponds to a respective one of the plurality of pieces of K-space completion data.