A method of reducing artifacts produced during Fast Spin Echo measurements made using permanent magnet NMR instruments. The method includes applying encoding gradients that do not switch signs throughout the experiment. Prior to the 90° RF pulse, a strong RM gradient pulse is given to produce a dominant and constant residual magnetization. The encoding is done through the combination of encoding gradients with the aid of the 180° RF pulses of the echo train. A first constant encoding gradient is given before the first 180 pulse. Then two variable encoding gradients are provided after each 180 pulse; one applied prior to and one applied subsequent to each acquisition in the echo train.