Table 2:

Detection of the presence of dural AVF by MRDSA and by IADSA

	Reviewer	MRDSA		IADSA		Sensitivity (%)	Specificity (%)	Positive Predictive Value (%)	Negative Predictive Value (%)
	Reviewer	Present	Absent	Present	Absent	Sensitivity (%)	Specificity (%)	Positive Predictive Value (%)	Negative Predictive Value (%)
Preoperative study
Feeding arteries	R1	3	21	23	1	13.0	100	100	4.8
	R2	2	22			8.7	100	100	4.5
Early venous filling	R1	24	0	23	1	100	—^*	95.8	0/0
	R2	24	0			100	—^*	95.8	0/0
Sinus occlusion	R1	1	23	1	23	100	100	100	100
	R2	1	23			100	100	100	100
Leptomeningeal venous drainage	R1	12	12	16	8	75.0	100	100	66.7
	R2	14	10			87.5	100	100	80
Varices	R1	5	19	5	19	100	100	100	100
	R2	5	19			100	100	100	100
Pseudophrebitic pattern	R1	3	21	3	21	100	100	100	100
	R2	2	22			66.7	100	100	95.4
Postoperative and follow-up study
Feeding arteries	R1	0	22	3	19	0	100	100	13.6
	R2	1	21			33.3	100	100	9.5
Early venous filling	R1	6	16	6	16	100	100	100	100
	R2	5	17			83.3	100	100	94.1
Sinus occlusion	R1	0	22	0	22	100	100	100	100
	R2	0	22			100	100	100	100
Leptomeningeal venous drainage	R1	2	20	1	21	—^*	90.4	0/2	95.0
	R2	0	22			—^*	100	100	95.4
Varices	R1	0	22	0	22	100	100	100	100
	R2	0	22			100	100	100	100
Pseudophrebitic pattern	R1	0	22	0	22	100	100	100	100
	R2	0	22			100	100	100	100

* Not calculated because of the small number. R1 indicates reviewer 1; R2, reviewer 2.
Note.—AVF indicates arteriovenous fistula; MRDSA, magnetic resonance digital subtraction angiography; IADSA, intraarterial digital subtraction angiography.