Fig. 4
From: Anatomical variation of the sacroiliac joints: an MRI study with synthetic CT images
Multiple sacroiliac joint (SIJ) variants coexisting in one patient. Semi-axial (a) and axial (b) synthetic CT images of multiple coexisting variants in a 27-year-old woman. An accessory SIJ is visible posterior to the cartilaginous part of the SIJ on both sides (short arrow), as well as crescent iliac bony plate (curved arrow). Additionally, dysmorphic SIJ (long arrow) accompanied by degenerative subchondral cyst and bipartite iliac bony plate (arrowhead) are present on the right side. Also note erosions and marked sclerosis on the left side