| 摘要 |
A magnetic resonance imaging apparatus includes a static magnetic field forming magnet, an RF coil and a transmitter/receiver adapted to transmit a 90 DEG rf pulse and a 180 DEG rf pulse in turn to a human body under examination and receive an echo signal from the human body, gradient magnetic field forming coils and gradient magnetic field power supplies adapted to form a first slice selection gradient magnetic field simultaneously with the 90 DEG rf pulse and a second slice selection gradient magnetic field simultaneously with the 180 DEG rf pulse, a computer system adapted to reconstruct a magnetic resonance image from the echo signal, and a display unit adapted to visualize the reconstructed magnetic resonance image. The frequency bandwidth of the 90 DEG rf pulse is adjusted so that a region in which proton spins in water are excited and a region in which proton spins in fat are excited will not overlap each other. The first and second slice selection magnetic fields are made opposite in polarity to each other. Water proton spins that have been subjected to the 90 DEG rf pulse will also be subjected to the 180 DEG rf pulse, thereby producing a magnetic resonance signal. Fat proton spins that have been subjected to the 90 DEG rf pulse will not be subjected to the 180 DEG rf pulse. The fat proton spins will not produce a magnetic resonance signal.
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