Whole Slide Image Information Object Definition (WSI IOD) from DICOM supplement 145 proposes storing tiles from a multi resolution hierarchy in multi-frame object(s). Each tile is stored in a Frame and is located within a 232x232 total pixel matrix. Specific Z planes or/and optical paths may be specified at the frame level.
Daniel et al. Diagnostic Pathology 2011 6(Suppl 1):S17 doi:10.1186/1746-1596-6-S1-S17