Four QD surface coil assemblies each constituted by an 8-shaped coil and a rectangular coil are one-dimensionally arranged under the spine array of a patient in the direction of the body axis of the patient. Each 8-shaped coil senses an RF magnetic field in an x direction near the spine array of the patient, and each rectangular coil senses an RF magnetic field in a y direction. Outputs from the 8-shaped coils and the rectangular coils are input to 90.degree. hybrid combiner circuits through pre-amplifiers, the phase of any one of the outputs is shifted by 90.degree., and then the outputs are added to each other. Outputs from the 90.degree. hybrid combiner circuits are supplied as raw data, through receiver/data acquisition systems, to a data processing unit (computer). In the data processing unit, raw data are two-dimensionally Fourier-transformed to form image signals p.sub.i (x,y,z) (i=1 to 4). The signals p.sub.1 (x,y,z) are squared, the sum of p.sub.i (x,y,z) is calculated with respect to i, and finally, the square root of the sum is calculated to obtain an image.