DIAGNOSTIC ACCURACY OF MAGNETIC RESONANCE IMAGING IN PREOPERATIVE ASSESSMENT OF PERIANAL FISTULAE AND ABSCESSES

Background: Perianal fistulae and abscesses are the different manifestations of the same clinical disease. They have been afflicting humans since ages. Although the disease is benign, it still adversely affects the patient’s quality of life. Up to 38% fistulae in ano arise from perianal abscesses. This study is aimed at determining the diagnostic accuracy of magnetic resonance imaging (MRI) in preoperative assessment of fistula in ano and perianal abscess, taking surgical confirmation as gold standard for the diagnosis. Methods: This cross-sectional validation study was conducted at Department of Radiology, Pakistan Institute of Medical Sciences, Islamabad, over a period of 6 months. In this study a total of 121 patients were enrolled using WHO software for sample size determination and by consecutive sampling (non-probability) technique. Results: The mean age of the patients was 43±12.77 years. Sixty-eight percent patients were male while 32% patients were female. Diagnostic accuracy of MRI for perianal fistula assessment was 95.04%, Sensitivity 95.72%, Specificity 75%, Positive predictive value 99.11%, and Negative predictive value was 37.50%. Diagnostic accuracy of MRI of abscess on the basis of surgical findings turned out to be 90.08%, Sensitivity 91.45%, Specificity 50%, Positive predictive value 98.16%, and Negative predictive value 16.66%. Conclusion: MRI is quite an accurate, non-invasive imaging technique for determination of type and extent of peri-anal fistula and abscess. Pak J Physiol 2024;20(4):65-7, DOI: https://doi.org/10.69656/pjp.v20i4.1552