Endoscopic ultrasound (EUS)
Endoscopic ultrasound is an emerging technology that uses an ultrasound probe mounted on the end of an endoscope. This allows much closer assessment and, as a result, better definition of internal organs than conventional transabdominal ultrasound. It also allows for interventions to be performed simultaneously – such as fine needle biopsies of tumours that were previously difficult to reach. Endoscopic ultrasound is either radial or longitudinal. Different information is gathered from each technique.
This form of radial ultrasound is used primarily is the assessment of oesophageal cancers. Fine detail regarding tumour penetration and lymph node spread can be obtained.
Hepatopancreaticobiliary EUS looks at conditions affecting the liver, biliary system and pancreas. It is most commonly used for assessment and biopsy of pancreatic tumours or cysts.
Anorectal EUS can be either radial or longitudinal. Radial EUS is used to assess the anal sphincter and peri-anal conditions. Longitudinal EUS can be used to assess the pelvic organs and can be very useful in the work-up of vaginal and rectal prolapse.