title: Anoperineal disease in Hidradenitis Suppurativa : MR imaging distinction from perianal Crohn's disease.
abstract: OBJECTIVE
  To determine whether Hidradenitis suppurativa (HS)-related anoperineal disease can be distinguished from Crohn's disease (CD) using MRI.
  
  
  METHODS
  Pelvic MRI of 23 HS and 46 CD patients with anoperineal disease between 2007 and 2014 were independently analysed by two radiologists. For diagnosis of HS, sensitivity, specificity and positive likelihood ratios (LRs) of inflammatory features and of their anatomical distribution were calculated and compared to those of CD.
  
  
  RESULTS
  In HS, fistulae were less present (P = .033) and less frequently involved the sphincters (P = .001) than in CD. Granulomas were more frequent (P = .0005). For anterior/inguinal and posterior localizations, sensitivity, specificity and LR for diagnosis of HS were 70% (49.1, 84.4), 87% (74.3, 93.9), 5.3 (2.41, 11.79) and 57% (36.8, 74.4), 93% (82.5, 97.8), 8.67 (2.74, 27.41), respectively. Combination of signs including posterior involvement, absence of rectal wall thickening and bilaterality of features yielded specificity of 100% (95% CI: 92.3-100) for HS.
  
  
  CONCLUSIONS
  Although MRI presentations of anoperineal disease may overlap between CD and HS, specific diagnosis of HS is possible with a combination of three features: absence of features' predominance in perianal area, absence of rectal wall thickening and bilaterality of features.
  
  
  CONCLUSIONS
  • Spectrum of MRI features of HS-related anoperineal disease is wide. • Specific diagnosis of HS-related anoperineal disease is possible using MR imaging. • A combination of three MR signs allows distinction between HS and CD.
authors.affiliation: Department of Radiology, Hôpital Maison Blanche, Avenue du Général Koenig, 51092, Reims Cedex, France. louisemonnier@live.fr.
authors.forename: Louise
authors.identifier: http://orcid.org/0000-0002-3387-6821
authors.initials: L
authors.lastname: Monnier
authors.affiliation: Department of Radiology, Hôpital Lariboisière, Assistance Publique-Hôpitaux de Paris, 2 rue Ambroise Paré, 75010, Paris, France.|Université Paris-Diderot, Sorbonne Paris Cité, 10 Avenue de Verdun, 75010, Paris, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Dohan
authors.affiliation: Department of Radiology, Hôpital Maison Blanche, Avenue du Général Koenig, 51092, Reims Cedex, France.
authors.forename: Nedjoua
authors.initials: N
authors.lastname: Amara
authors.affiliation: Department of Radiology, Saint Louis Hospital, 1 Avenue Claude Vellefaux, 75010, Paris, France.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Zagdanski
authors.affiliation: Department of Statistics, Hôpital Robert Debré, Avenue du Général Koenig, 51092, Reims Cedex, France.
authors.forename: Moustapha
authors.initials: M
authors.lastname: Drame
authors.affiliation: Université Paris-Diderot, Sorbonne Paris Cité, 10 Avenue de Verdun, 75010, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Soyer
authors.affiliation: Department of Radiology, Hôpital Maison Blanche, Avenue du Général Koenig, 51092, Reims Cedex, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Hoeffel
mesh_terms: D000328:Adult; D000368:Aged; D003424:Crohn Disease / Q000000981:diagnostic imaging*; D005260:Female; D017497:Hidradenitis Suppurativa / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging; D010502:Perineum / Q000000981:diagnostic imaging; D012003:Rectal Fistula / Q000000981:diagnostic imaging; D012007:Rectum / Q000000981:diagnostic imaging; D012680:Sensitivity and Specificity; D055815:Young Adult
keywords: Crohn’s disease; Hidradenitis suppurativa; Magnetic resonance imaging; Perineum; Rectal fistula