Composition of MRI Slabs

The abdominal MRI under review is composed of three slabs of around 100 slices each. The slabs are acquired in hold-breath supine position taking around 20 seconds. Naturally, a step between two such slabs may occur due to different breathing statuses. I understand that Slicer covers a wide range of registration techniques, which is why I’m kindly asking for somebody to point me in the right direction.