The Sonographic Appearance of theAnal Canal by Endoanal Sonography with a 7 mmProbeEndosonographische Darstellung desanalen Kanals mittels 7-mm-Sonde

Imaging of the anorectal region has drastically changed over the past decade by the introduction of anal endosonography. This method has been used to localize injuries to the anal sphincters, fistula tracts and abscesses as well as to assess local invasion of cancerous lesions. It allows a quick and easy visualisation of the anorectal mucosa and the surrounding muscular structures. Limitations of endosonography include strictures and acute painful conditions. These caveats are largely caused by the size of regular rectal probes with an average diameter of 17 to 20 mm.