Table 2

Performances of the different imaging abnormalities ‘typical of axSpA’ with regard to axSpA recognition

Se (95% CI)Spe (95% CI)LR+ (95% CI)
XraysPelvic XraysLesionsErosion (y/n)*0.4(0.3,0.5)0.9(0.8,0.9)3.8(1.9,7.4)
Sclerosis (y/n)0.5(0.4,0.6)0.8(0.7,0.9)2.3(1.5,3.5)
Joint widening (y/n)0.3 (0.2, 0.4)0.9 (0.8, 0.9)1.9 (1.0, 3.4)
Joint narrowing (y/n)0.2 (0.1, 0.3)0.9 (0.8, 0.9)1.9 (0.9, 3.6)
Partial ankylosis (y/n)0.1 (0.1, 0.2)0.9 (0.9, 0.9)1.5 (0.6, 3.8)
Total ankylosis (y/n)0.0 (0.0, 0.1)1.0 (0.9, 1.0)NA*
At least a gradetwounilaterally0.54(0.4,0.6)0.7(0.6,0.8)2.0(1.4,2.9)
Modified NY criteria0.4(0.3,0.5)0.9(0.8,0.9)3.0(1.6,5.6)
Spine XraysLesionsAt least one erosion0.1 (0.1,0.2)0.8 (0.7,0.9)0.7 (0.4, 1.2)
At least one sclerosis lesion0.2 (0.2,0.3)0.8 (0.7,0.9)1.3 (0.7, 2.3)
At least one squaring lesions0.1 (0.0, 0.1)1.0 (0.9, 1.0)5.7 (0.7, 46.5)
At least one full bone bridge0.1 (0.0,0.1)1.0 (0.9,1.0)2.5 (0.5, 12.7)
MRIInflammatory lesionsSacroiliac jointsAt least one inflammatory lesion0.4 (0.3, 0.5)0.8 (0.7, 0.8)1.6 (1.0, 2.4)
ASAS definition of positive MRI sacroiliitis0.4(0.3,0.5)0.9(0.8,0.9)4.2(2.0,8.5)
ASAS definition of MRI sacroiliitis AND deep lesion0.2(0.1,0.3)1.0(0.9,1.0)16.2(2.2,119.0)
ASAS definition of MRI sacroiliitis AND intense lesion†0.2(0.1,0.3)1.0(0.9,1.0)9.5(2.3,39.6)
ASAS definition of MRI sacroiliitis AND (deep OR intense lesion)†0.2(0.2,0.3)1.0(0.9,1.0)7.6(2.4,24.2)
ASAS definition of MRI sacroiliitis AND (deep AND intense lesion)†0.1 (0.1, 0.2)1.0 (0.9, 1.0)NA*
SpineAt least one inflammatory lesion0.5 (0.4, 0.6)0.6 (0.5, 0.7)1.2 (0.9, 1.6)
At least three inflammatory lesions (ASAS definition of positive spine MRI)0.4 (0.3, 0.6)0.7 (0.6, 0.8)1.4 (0.9, 1.9)
At least five inflammatory lesions0.3 (0.2, 0.4)0.7 (0.7, 0.8)1.2 (0.8, 1.9)
Structural lesionsSacroiliac jointsAt least one structural lesion0.2 (0.2, 0.3)0.8 (0.7, 0.0)1.4 (0.8, 2.5)
At leastthreeerosions0.3(0.2,0.4)0.9(0.8,1.0)3.0(1.6,5.8)
At leastthreefatty lesions0.3(0.2,0.4)0.9(0.8,0.9)2.5(1.3,4.7)
At leastfivestructural lesions (erosions or fatty lesions)0.3(0.2,0.4)0.9(0.8,0.9)2.4(1.4,4.3)
SpineAt least one structural lesion0.4 (0.3, 0.5)0.5 (0.4, 0.6)0.8 (0.6, 1.2)
At least three erosions0.1 (0.0, 0.1)0.9 (0.9, 1.0)1.2 (0.4, 3.3)
At least three fatty lesions0.2 (0.1, 0.2)0.8 (0.7, 0.9)0.7 (0.4, 1.2)
At least five fatty lesions0.1 (0.0, 0.2)0.9 (0.8, 0.9)0.7 (0.3, 1.7)
At least five structural lesions (erosions OR fatty lesions)0.1 (0.1, 0.2)0.8 (0.7, 0.9)0.6 (0.3, 1.1)
  • *NA=not applicable, since one of the categories is 0, thus not calculable.

  • †According to the SPARCC scoring method.

  • ‡LR+ => 2 (considered relevant) are highlighted in bold

  • ASAS, Assessment of SpondyloArthritis international Society; CBP, chronic back pain; NY, New York; axSpA, axial Spondyloarthritis.