PROBLEM TO BE SOLVED: To provide a magnetic resonance imaging apparatus for reducing image deterioration due to ununiformity in magnetic field, such as ununiformity in static magnetic field or ununiformity in RF transmission magnetic field.SOLUTION: The apparatus is configured to sequentially transmit RF pulses 90°x, &alpha1°y, &alpha2°y, -&alpha1°y, -&alpha2°y, and -90°x. The flip angle &alpha1° of the RF pulse &alpha1°y is expressed in the equation: &alpha1°=180°-&Deltad1°, the flip angle &alpha2° of the RF pulse &alpha2° is expressed in the equation: as &alpha2°=180°+&Deltad2°, the flip angle -&alpha1° of the RF pulse -&alpha1°y is expressed in the equation: -&alpha1°= -(180°-&Deltad1°), and the flip angle -&alpha2° of the RF pulse -&alpha2°y s expressed in the equation: -&alpha2°= -(180°+&Deltad2°). Further, time intervals &Deltat1, &Deltat2, &Deltat3, &Deltat4, and &Deltat5 of the RF pulses 90°x, &alpha1°y, &alpha2°y, -&alpha1°y, -&alpha2°y, and -90°x are set in such a manner that the following relationship is established: &Deltat1:&Deltat2:&Deltat3:&Deltat4:&Deltat5=1:2:2:2:1.COPYRIGHT: (C)2011,JPO&INPIT【課題】静磁場不均一やRF送信磁場不均一などの磁場不均一による画質の劣化を低減する磁気共鳴イメージング装置を提供する。【解決手段】RFパルス90°x、α1°y、α2°y、-α1°y、-α2°y、および-90°xを順に送信する。RFパルスα1°yのフリップ角α1°を、α1°=180°-Δd1°、RFパルスα2°のフリップ角α2°を、α2°=180°+Δd2°、RFパルス-α1°yのフリップ角-α1°を-α1°=-(180°-Δd1°)、RFパルス-α2°yのフリップ角-α2°を-α2°=-(180°+Δd2°)とする。更に、RFパルス90°x、α1°y、α2°y、-α1°y、-α2°y、および-90°xの時間間隔Δt1、Δt2、Δt3、Δt4、およびΔt5は、Δt1:Δt2:Δt3:Δt4:Δt5=1:2:2:2:1とする。【選択図】図5
