title: Transperineal and transvaginal sonography of perianal inflammatory disease.
abstract: OBJECTIVE
  Perianal infection arises in small intersphincteric anal glands predominantly located at the dentate line. Documentation of fluid collections and the relationship of inflammatory tracts to the sphincter mechanism is important for surgical treatment. Transanal sonography for assessment of perianal inflammatory disease is limited because placement of the rigid probe into the anal canal does not allow assessment of disease in the perineal region. The purpose of this study was to validate the use of transperineal sonography in men and both transvaginal and transperineal sonography in women for evaluation of perianal inflammatory disease.
  
  
  METHODS
  Fifty-four patients, 28 men and 26 women, were imaged with transperineal and a combination of transperineal and transvaginal sonography, respectively. All patients were examined in the supine lithotomy and left lateral position with a transvaginal 8-to 4-MHz probe or a linear 12- to 7-MHz transducer. All fluid collections, sinus tracts, and fistulas were described by their location in relation to the sphincter mechanism and perineum.
  
  
  RESULTS
  Forty-six of 54 patients had perianal fistulas or sinus tracts: 33 transphincteric, seven intersphincteric, and six extrasphincteric. Fifteen patients had an associated abscess. In the eight remaining patients, there were two anovaginal fistulas, one rectovaginal fistula, one prolapsed internal hemorrhoid, two perianal complex masses, and two vascular perianal or perirectal inflammatory masses. Twenty-six patients underwent surgical procedures involving the anorectal canal or perirectal region, and of these, preoperative sonographic findings were confirmed in 22 (85%) of 26 patients. Three patients refused surgery, and six are awaiting surgery at this writing. Fifteen patients were treated conservatively.
  
  
  CONCLUSIONS
  Transperineal and transvaginal sonography are accurate, painless, and cost-effective methods for documenting perianal fluid collections and fistulas or sinus tracts or both.
authors.affiliation: Department of Medical Imaging, Toronto General Hospital-University Health Network, 200 Elizabeth St., Toronto, Ontario, Canada M5G 2C4.
authors.forename: L K
authors.initials: LK
authors.lastname: Stewart
authors.forename: J
authors.initials: J
authors.lastname: McGee
authors.forename: S R
authors.initials: SR
authors.lastname: Wilson
mesh_terms: D000038:Abscess / Q000000981:diagnostic imaging; D000328:Adult; D000368:Aged; D003093:Colitis, Ulcerative / Q000000981:diagnostic imaging; D003424:Crohn Disease / Q000000981:diagnostic imaging; D017577:Cutaneous Fistula / Q000000981:diagnostic imaging; D019160:Endosonography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011349:Proctitis / Q000000981:diagnostic imaging*; D012003:Rectal Fistula / Q000000981:diagnostic imaging*; D012006:Rectovaginal Fistula / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity