Patent ID: 8594766

Claim:
A magnetic resonance imaging apparatus comprising: a magnetic field generation system configured to generate each of a static magnetic field, an RF magnetic field, and a gradient magnetic field; a transfer unit configured to move a subject at a moving velocity in a moving direction in the static magnetic field; a signal processing system configured to measure a nuclear magnetic resonance signal generated from the subject and produce an image of the subject; an imaging controller which controls the magnetic field generation system, the transfer unit and the signal processing system, and which executes, while moving the transfer unit continuously, an imaging sequence for measuring multiple nuclear magnetic resonance signals by applying multiple readout gradient magnetic fields, after applying RF pulse of one-time excitation; and a phase calculation unit configured to calculate a phase difference produced by a positional deviation of the readout gradient magnetic fields between echoes, given to the multiple nuclear magnetic resonance signals, the positional deviation being caused by the continuous movement of the transfer unit, the moving direction being a readout gradient direction of the readout gradient magnetic fields, and the phase difference being calculated by using a value of readout gradient (Gr), application time of the readout gradient pulse (Δt), a signal acquisition interval (IET) and a positional shift (Δx) along the moving direction in the signal acquisition interval IET, wherein the phase calculation unit applies one of formula (5) and formula (5′) to calculate the phase difference θ: θ=Δω×Δ t MOD 2π=(γ× Gr×Δx )×Δ t MOD 2π (5), and θ( t )=∫Δω( t ) dt MOD 2π=∫[γ× Gr×Δx ( t )] dt MOD 2π (5′), where Δω represents a difference in angular frequency caused by the positional deviation, and γ represents a gyromagnetic ratio, the imaging controller corrects the phase difference calculated by the phase calculation unit.