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

Table 4 Efficacy parameters in relation to surgery for the different diagnostic techniques: Sensitivity, specificity, positive predictive value and negative predictive value

		S	SP	PPV	NPV
IO identified (%)	PE	76	33	96	6
	2D-EAUS	98	66	98	66
	3D-EAUS	98	66	98	66
Primary tract (%)
Intersphincteric	PE	69	82	47	92
	2D-EAUS	77	93	71	95
	3D-EAUS	22	98	90	93
Transsphincteric
Low	PE	45	81	68	67
	2D-EAUS	67	92	88	75
	3D-EAUS	85	84	82	86
High	PE	38	87	68	78
	2D-EAUS	64	76	70	70
	3D-EAUS	88	91	84	93
Secondary tract (%)	PE	40	97	67	91
	2D-EAUS	90	90	60	98
	3D-EAUS	90	88	56	98

2D-EAUS: Two-dimensional endoanal ultrasound; 3D-EAUS: Three-dimensional endoanal ultrasound; PE: Physical examination; IO: Internal opening; S: Sensitivity; SP: Specificity; PPV: Positive predictive value; NPV: Negative predictive value.