1. A high-speed magnetic resonance imaging (MRI) method comprising: applying, to a subject, a radio frequency (RF) pulse sequence; splitting magnetic resonance signals produced in response to the RF pulse sequence based on sampling intervals between samples that configure a k-space and based on image resolutions of magnetic resonance images corresponding to the magnetic resonance signals, wherein sampling intervals of the magnetic resonance signals vary; and producing the magnetic resonance images with different resolutions using the split magnetic resonance signals, wherein the magnetic resonance images with different resolutions comprise a full-length body image with a lower resolution and an expanded image of an area of interest with a higher resolution.