FIG. 2.

Spiral 3D TSE sequence diagram and resulting k-space trajectory. The same interleaf from each 3D phase encode is acquired in a single echo train. Partitions (3D phase encodes) are acquired linearly through the third k-space dimension and scrolled to achieve the desired TE. Echo train 1 acquires the red interleaf from partitions 1, 2, and 3, with partition 2 encoded as the center partition. After a wait time TR, echo train 2 acquires the green interleaf, and so on. Within each echo spacing, the net area of the readout gradients is zero.