Artefacts
Multi-slice helical interpolation artefacts probably worse than single slice, for the same pitchx
Narrow collimation and high pitch gives reduced artefacts relative to wider collimation and low pitch
Pitchd 3, Collimation 2.5 mm 3mm slice
Pitchd 7, Collimation 1 mm3mm slice
Images courtesty of Siemens