title: Perspective on the role of transrectal and transvaginal sonography of tumors of the rectum and anal canal.
abstract: OBJECTIVE
  Intestinal sonography is characterized by excellent resolution of the multiple layers of the intestinal wall and sensitive depiction of the degree of invasion of rectal tumors. Traditional transrectal sonography has been enhanced by the addition of transvaginal scanning for women and by advances in transducer technology. Our purpose is to describe the current status of sonography in the evaluation of rectal and anal tumors and in the staging of rectal cancer.
  
  
  CONCLUSIONS
  Endorectal and transanal sonography are fast, minimally invasive techniques that can be performed with portable equipment and yield rapidly interpreted images. They are considered the reference standard for the preoperative staging of rectal and anal cancers and have relatively high accuracy in categorization of tumors and nodes in TNM staging.
authors.affiliation: Section of Ultrasound, Department of Medical Imaging, Toronto General Hospital, University of Toronto, Toronto, ON, Canada.
authors.forename: Francesca
authors.initials: F
authors.lastname: Berton
authors.forename: Giada
authors.initials: G
authors.lastname: Gola
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Wilson
mesh_terms: D001005:Anus Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging*; D012007:Rectum / Q000000981:diagnostic imaging*; D014463:Ultrasonography; D014621:Vagina / Q000000981:diagnostic imaging*