Table 1.

The existing grading criteria of SIJ CT

mNY criteriaLee criteriaInnsbruck criteria
0 = Normal
1 = Suspicious for erosions or sclerosis
2 = Mildly abnormal with definite erosions or sclerosis, but without alteration in the joint width
3 = Moderately abnormal with erosions or sclerosis, joint space narrowing or widening and/or partial ankylosis
4 = Complete ankylosis		0 = Normal
1 = Focal erosions seen on only one of either semi-coronal or axial images
2 = ≤25% erosions*, but without alteration in the joint width
3 = ≥25% erosions*, joint space alteration and/or partial ankylosis
4 = Complete ankylosis		IA = SIJ>4 mm
IB = SIJ<2 mm
IIA = Contour irregularities
IIB = Erosion
IIIA = Subchondral sclerosis
IIIB = Spur formation
IVA = Transarticular bony bridges
IVB = Ankylosis

  • *Extent of erosions; (%) = number of slices with erosions/total number of slices × 100.