Fig. 2.

(a) Pulse sequence diagram of tag-on and tag-off 3D acquisition using 3D cSSFSE with magnetization states. Each slice encoding of tag-on and tag-off acquisitions is alternately acquired. Pre-pulse such as SPAIR fat suppression pulse can be applied before the readout acquisition. (b) Post-processing of 3D Fourier-transformed data of tag-off and tag-on brain images with a rectangular tag position in red (images at TI of 1500 ms, image details in Fig. 4). Simple subtraction enables visualization of movement of the tagged signal out of the tag region. cSSFSE, centric k_y–k_z single-shot fast spin echo; SPAIR, spectral adiabatic inversion recovery.