Table 3.

Comparison of X-ray and MRI examinations in identifying inflammatory changes with the use of the Cohen’s kappa coefficient.

		MRI		Total
Radiographs	Blurred margins/oedema	Absent	Present
	Absent	105	36	141
	Present	29	26	55
	Total	134	62	196
Comparison	Radiographs and MRI agreement=67% Cohen’s kappa coefficient=0.21; CI: 0.05–0.37
		MRI		Total
Radiographs	Subchondral sclerosis	Absent	Present
	Absent	76	59	135
	Present	17	44	61
	Total	93	103	196
Comparison	Radiographs and MRI agreement=61% Cohen’s kappa coefficient=0.24; CI: 0.11–0.37
		MRI		Total
Radiographs	Change in joint space width	Absent	Present
	Absent	172	6	178
	Present	12	6	18
	Total	184	12	196
Comparison	Radiographs and MRI agreement=91.0% Cohen’s kappa coefficient=0.35;CI: 0.07–0.64
		MRI
Radiographs	Erosions	Absent	Present	Total
	Absent	164	26	190
	Present	3	3	6
	Total	167	29	196
Comparison	Radiographs and MRI agreement=85% Cohen’s kappa coefficient=0.13;CI: 0.0–0.42
		MRI
Radiographs	Bony Ankylosis	Absent	Present	Total
	Absent	193	2	195
	Present	0	1	1
	Total	193	3	196
Ccomparison	Radiographs and MRI agreement=99.0% Cohen’s kappa coefficient=0.5; CI: 0.0–1.0