1. Ultrahigh speed magnetic resonance imaging equipment, comprising: an excitation and detection unit configured to expose a spatially displacing object to be imaged to a static magnetic field, to apply a radiofrequency wave and a gradient magnetic field temporally constant in an x direction, y direction or z direction in an orthogonal coordinates system, and to observe signals specified by temporal and spatial distributions of nuclear magnetic resonance elements induced in the object within k-space, receiver means for collecting the signals distributed in the k-space and observing upper N points (N is an integer; N=1, 2, 3,. .. ) from the signals according to a sequence in largeness of amounts of data, and image display means for reconstructing the signals as images, said excitation and detection unit having a function to observe signals only at the upper N points in time series as data of a reference image, said receiver means having a function to calculate changes in phase of the signals at the upper N points based on the data of the reference image to obtain calculation results and continuously estimate a motion of the object to be imaged between measurement times based on the calculation results and phase distributions and amplitudes of the signals at the upper N points, and said image display means having a function to complement unacquired data based on the estimated motion and to reconstruct a three-dimensional image.