Utility of MR Fistulography for Evaluation of the Suspected Case of Perianal Fistulas in Correlation with Intraoperative Findings

Background: Perianal fistulas are abnormal tracts connecting the anal canal to the perianal skin, often leading to recurring infections and significant morbidity. Magnetic Resonance Fistulography (MRF) has emerged as the gold standard for evaluating perianal fistulas by providing detailed anatomical visualization, aiding surgical planning, and minimizing recurrence rates. Objectives: To evaluate the utility of MR Fistulography in diagnosing and classifying perianal fistulas and to assess its correlation with intraoperative findings. The study also aimed to determine the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MRF. Methods: This prospective observational study involved 40 patients with suspected perianal fistulas who underwent MR Fistulography followed by surgical exploration. MRF findings were compared with intraoperative observations to evaluate diagnostic accuracy. Statistical analyses were performed using SPSS. Results: MR Fistulography demonstrated high diagnostic accuracy, with a sensitivity of 94%, specificity of 85%, and an overall accuracy of 91%. Agreement between MRF and intraoperative findings was 95% for primary tracts, 92% for secondary tracts, and 83% for abscesses. The majority of fistulas were intersphincteric and transsphincteric, accounting for 80% of cases, with ischiorectal abscesses being the most common (42.5%). Conclusion: MR Fistulography is a highly effective diagnostic tool for evaluating perianal fistulas, providing detailed preoperative mapping that enhances surgical outcomes and reduces recurrence rates. Its high sensitivity and specificity make it the gold standard imaging modality for these conditions.