Purpose: To compare a STIR sequence with gadolinium‐enhanced techniques on endoanal magnetic resonance (MR) imaging of fistulas‐in‐ano by correlating the findings with those at surgery. Material and Methods: Twenty‐two consecutive patients with clinical suspicion of perianal sepsis were studied using an endoanal coil followed immediately by a phased array coil. T1‐weighted precontrast and postcontrast and STIR images in transverse and coronal planes were produced with each coil and analysed by noting the presence and site of a collection, primary track, the position of any internal opening, and subcutaneous or supralevator extension. An “expert” and also a “trainee” radiologist assessed the images. Operative findings were similarly recorded. The Fisher exact test was used to compare imaging with surgery. Interobserver variation was calculated using a kappa statistic. Results: Of 22 patients with suspected fistulas, 8 were simple, 4 were complex, and 3 were superficial sinuses. Five had no anal pathology, 1 had anal excoriation, and 1 had a polyp. At surgery, 6 intersphincteric, 1 transsphincteric, 8 extrasphincteric, no supralevator collections, and 9 internal openings were noted. The overall sensitivity and specificity for detecting these were 75% and 64%, respectively, for STIR imaging, and 58.3% and 62.8% for gadolinium‐enhanced imaging. There was good agreement between the “trainee” and the “expert” in the interpretation of images (kappa = 0.7). Conclusion: A STIR sequence is more sensitive overall than gadolinium‐enhanced techniques on endoanal magnetic resonance imaging of fistulas‐in‐ano because of increased sensitivity in detecting the internal opening. A combination of endoanal and phased array techniques using STIR imaging sequences is valuable preoperative assessment in both simple and complex cases.
Preoperative assessment of deep myometrial and cervical invasion in endometrial carcinoma: Comparison of magnetic resonance imaging and histopathologic evaluation