title: Imaging of acute anorectal conditions with CT and MRI.
abstract: Anorectal disorders are a common cause of presentation to the emergency department (ED). While the most frequently encountered anorectal conditions, such as hemorrhoids and anal fissures, are relatively benign and do not require imaging for diagnosis or management, there are multiple potentially life threatening anorectal conditions for which imaging is an important component of evaluation, diagnosis, and management. Although computed tomography (CT) is the most commonly used imaging modality for evaluation of anorectal pathology in the ED, magnetic resonance imaging (MRI) has an increasingly important role in the detection, characterization and management of specific anorectal conditions. This pictorial essay will review the imaging anatomy of the anorectum, summarize imaging protocols, and discuss the clinical presentation, imaging appearance, and differential diagnosis of anorectal conditions that may present to the emergency department, including infectious, inflammatory, malignant and vascular conditions.
authors.affiliation: Department of Radiology, New York-Presbyterian Hospital, Weill Cornell Medical College of Cornell University, 525 East 68th Street, Starr 900, New York, NY, 10065, USA. prg9018@med.cornell.edu.
authors.forename: Preethi
authors.identifier: 0000-0001-6178-4089
authors.initials: P
authors.lastname: Guniganti
authors.affiliation: Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Pl, Box 1234, New York, NY, 10029, USA.
authors.forename: Sara
authors.initials: S
authors.lastname: Lewis
authors.affiliation: Department of Radiology, Icahn School of Medicine at Mount Sinai, One Gustave Levy Pl, Box 1234, New York, NY, 10029, USA.
authors.forename: Ally
authors.initials: A
authors.lastname: Rosen
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University in St. Louis, 510 S. Kingshighway, St. Louis, MO, 63110, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Connolly
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University in St. Louis, 510 S. Kingshighway, St. Louis, MO, 63110, USA.
authors.forename: Constantine
authors.initials: C
authors.lastname: Raptis
authors.affiliation: Mallinckrodt Institute of Radiology, Washington University in St. Louis, 510 S. Kingshighway, St. Louis, MO, 63110, USA.
authors.forename: Vincent
authors.initials: V
authors.lastname: Mellnick
mesh_terms: D003937:Diagnosis, Differential; D006801:Humans; D008279:Magnetic Resonance Imaging; D012002:Rectal Diseases / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
keywords: Anorectal; Emergency; Fistula; Perianal; Proctitis