High-resolution direct magnetic resonance imaging fistulography with hydrogen peroxide for diagnosing anorectal fistula: A preliminary retrospective study

Table 5 Interobserver agreement across diagnostic modalities for detecting fistula-in-ano features

Observational indicator	Diagnostic modality	Kappa value	95%CI	Interpretation
Internal openings	Physical examination	0.48	0.40-0.56	Fair agreement
	TPUS	0.63	0.55-0.71	Moderate agreement
	Low-spatial-resolution MRI	0.78	0.71-0.85	Substantial agreement
	High-resolution HPMRI	0.89	0.83-0.95	Almost perfect agreement
Fistula tracks	Physical examination	0.41	0.34-0.48	Fair agreement
	TPUS	0.57	0.50-0.64	Moderate agreement
	Low-spatial-resolution MRI	0.74	0.68-0.80	Substantial agreement
	High-resolution HPMRI	0.85	0.79-0.91	Almost perfect agreement
Perianal abscess	Physical examination	0.33	0.25-0.41	Fair agreement
	TPUS	0.45	0.37-0.53	Moderate agreement
	Low-spatial-resolution MRI	0.69	0.62-0.76	Substantial agreement
	High-resolution HPMRI	0.8	0.74-0.86	Almost perfect agreement

HP: Hydrogen peroxide; MRI: Magnetic resonance imaging; TPUS: Trans-perineal ultrasonography.