FISTULA IN ANO - ENDOANAL SONOGRAPHY VERSUS ENDOANAL MR-IMAGING IN CLASSIFICATION

PURPOSE: To assess agreement between endoanal sonography, endoanal mag netic resonance (MR) imaging, and surgery in depiction and classificat ion of fistula in ano. MATERIALS AND METHODS: Twenty-eight consecutive patients with nonspecific, cryptoglandular fistula in ano were studie d. The fistulas were classified with endoanal sonography, endoanal MR imaging, and surgery. Agreement between the modalities was also evalua ted. RESULTS: Classification of fistulas was possible in 17 of 28 pati ents (61%) with sonography, in 25 of 28 (89%) with MR imaging, and in 26 of 28 (93%) with surgery. Concordance between endoanal sonography a nd MR imaging occurred in 46% of the cases (kappa = 0.27, poor agreeme nt); between sonography and surgery in 36% (kappa = 0.09, no agreement ); and between MR imaging and surgery in 64% (kappa = 0.43, moderate a greement). CONCLUSION: Endoanal MR imaging more accurately allows depi ction and classification of fistula in ano than endoanal sonography.