Table 3

Interobserver variability in measurement of degree of carotid stenosis on digital subtraction intra-arterial angiography, CT angiography, and MR angiography in asymptomatic arteries

Digital subtraction intra-arterial angiography
		Observer 1
		Operable	Not operable
Observer 2:	Operable	2	1
	Not operable	2	29	0.52*

MR angiography
		Observer 3
		Operable	Not operable	κ Value
Observer 4:	Operable	2	2
	Not operable	2	28	0.43*

Spiral CT angiography
		Observer 5
		Operable	Not operable	κ Value
*κ Values are not reliable owing to small numbers of operable stenoses.
CT, computed tomography; MR, magnetic resonance.
Observer 6:	Operable	3	1
	Not operable	2	28	0.62*