Two MNI volume shapes

Hi all,
looking at outputs of various fMRI preproccessing scripts, the results in either of two volume sizes. For example,for 3mm isometric, there is:

  • (61, 73, 61) - which is also the shape of MNI, Harvard-Oxford, Schaefer and probably more atlases, and
  • (72, 72, 47) - which is C-PAC default pipeline output shape, and sometimes SPM default.

What is the latter shape standard, and what is the easy way to convert between the two?

Thank you