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Fig 1. Pulse sequence diagram for a diffusion-weighted acquisition shows that 2 diffusion-sensitizing gradients (dark gray) are added to a spin-echo sequence, 1 before and 1 after the 180° refocusing pulse. The diffusion-weighting factor b depends on the amplitude of the diffusion gradient (G), the duration of each diffusion gradient (
), and the interval between the onset of the diffusion gradient before the refocusing pulse and that following the refocusing pulse (
). RF indicates radiofrequency pulses; Gz, gradient pulses.
