Imaging of the Anal Canal and Rectum

Prior to 1989 the only method of anal sphincter mapping was by utilising a painful technique of electromyography. Recently, new radiological techniques for anal sphincter imaging have evolved that include endoanal ultrasound and magnetic resonance imaging (with surface and endoluminal coils). These techniques are now available to provide information on anal sphincter anatomy in patients with traumatic or idiopathic faecal incontinence, anorectal sepsis and anorectal malignancy.