Three-dimensional endoanal ultrasound for diagnosis of perianal fistulas: Reliable and objective technique

Table 3 Concordance grade and k coefficient (k) between intraoperative findings and the different diagnostic techniques used

	PE		2D-EAUS		3D-EAUS
	Concordance	k	Concordance	k	Concordance	k
IO identified	51/70 (72.8%)	1	68/70 (97.1%)	1	68/70 (97.1%)	1
Primary tract	37/70 (52.9%)	0.33	55/70 (78.6%)	0.67	58/70 (82.8%)	0.75
Secondary tract	61/70 (87.1%)	0.44	64/70 (91.4%)	0.66	65/70 (92.8%)	0.60
Adjacent abscesses	58/70 (82.8%)	0.30	61/70 (87.1%)	0.57	60/70 (85.7%)	0.54

¹P > 0.05. k < 0: No agreement; k = 0: Concordance due to chance; k = 0-0.19: Insignificant; k = 0.2-0.39: Low; k = 0.4-0.59: Moderate; k = 0.6-0.79: good; k = 0.8-0.1: Very good. 2D-EAUS: Two dimensional endoanal ultrasound; 3D-EAUS: Three dimensional endoanal ultrasound; IO: Internal opening; PE: Physical examination.