论文部分内容阅读
利用自制的微成象系统,在7T的主磁场下,测量了模型样品的核磁共振图象中磁化率引起的失真。观察到图象的失真随频率编码梯度场强度的增大而减弱,对不同的成象脉冲序列,场梯度回波序列所产生的失真最大,自旋回波序列其次,双相位编码的脉冲序列则能完全消除磁化率效应引起的失真。
Using a home-made micro-imaging system, the distortion caused by the susceptibility in the nuclear magnetic resonance image of the model sample was measured under the main magnetic field of 7T. It is observed that the distortion of the image is weakened with the increase of the intensity of the frequency encoding gradient field. For different imaging pulse sequences, the distortion caused by the field gradient echo sequence is the largest, and the spin echo sequence is followed by the pulse sequence of the dual phase encoding Can completely eliminate the distortion caused by susceptibility effects.