Table 5.

Sacroiliitis diagnosis in relation to the final clinical diagnosis.

		Patients		Total
Radiographs +/− ray according to modNY	SIJ image	No axSpA	axSpA
	Normal	47 (47%)	39 (39%)	86 (86%)
	Sacroiliitis	3 (3%)	11 (11%)	14 (14%)
	Total	50 (50%)	50 (50%)	100 (100%)
Comparison	Sensitivity 22% (11/50), positive predictive value 79% (11/14), LR+ 3.67 Specificity 94% (47/50), negative predictive value 55% (47/86), LR – 0.83
		Patients		Total
MRI	SIJ image	No axSpA	axSpA
	Normal	45 (45%)	15 (15%)	60 (59%)
	Sacroiliitis	5 (5%)	36 (35%)	41 (41%)
	Total	50 (50%)	51 (50%)	101 (100%)
Comparison	Sensitivity 71% (36/51), positive predictive value 88% (36/41), LR+ 7.1 Specificity 90% (45/50), negative predictive value 75% (45/60), LR –0.32