In multi-echo imaging AND in multi-slice imaging AND when multi-echo and multi-slice are combined, each TE contributes a single line of k-space to a single image per TR. In the following example:

Excite Slice #1 >> 180 >> TE-a >> 180 >> TE-b | Excite Slice #2 >> 180 >> TE-a >> 180 >> TE-b | …….TR Excite Slice #1….

The above is repeated at TR for the number of phase encoding steps required (Np)

We will generate a single line of data for the following 4 images:

Slice #1/TE-a

Slice #1/TE-b

Slice #2/TE-a

Slice #2/TE-b

Slices 1, 2 with TE-b will represent the same anatomy, at greater T2 contrast, compared to Slices 1 and 2 with TE-a.