title: Prospective evaluation of an over-the-wire catheter US probe.
abstract: BACKGROUND
  Pancreaticobiliary strictures identified at endoscopic retrograde cholangiopancreatography (ERCP) can be evaluated by intraductal ultrasonography (US). Two major difficulties are that sphincterotomy may be required and the stricture may not be traversable. We prospectively evaluated the ease and success of intraductal US using a new over-the-wire catheter US probe.
  
  
  METHODS
  Biliary or pancreatic strictures discovered at ERCP were imaged with the new probe. Intraductal US performance times, image clarity, imaging depth and technical ease were measured.
  
  
  RESULTS
  Twenty-one patients with a variety of inflammatory and malignant pancreaticobiliary lesions were studied. Thirteen of the 16 (81%) masses imaged by intraductal US were 10 mm or less in diameter. Sphincterotomy was not required. All strictures traversed by a guidewire were imaged. The sphincter of Oddi was successfully imaged in all patients with intact normal sphincters. Performance of intraductal US was rated as technically easy in all cases and image clarity was rated as good or very good in 15 of 21 (71%) cases.
  
  
  CONCLUSIONS
  The new over-the-wire catheter US probe facilitates intraductal US. Sphincterotomy is avoided and strictures are successfully traversed. This probe makes it possible to image the sphincter of Oddi.
authors.affiliation: Division of Gastroenterology, University Hospitals of Cleveland and Cleveland VAMC, Case Western Reserve University, Cleveland, OH 44106-1736, USA.
authors.forename: A
authors.initials: A
authors.lastname: Chak
authors.forename: G
authors.initials: G
authors.lastname: Isenberg
authors.forename: K
authors.initials: K
authors.lastname: Kobayashi
authors.forename: R C
authors.initials: RC
authors.lastname: Wong
authors.forename: M V
authors.initials: MV
authors.lastname: Sivak
mesh_terms: D000328:Adult; D000368:Aged; D001652:Bile Ducts / Q000000981:diagnostic imaging*; D002404:Catheterization; D002779:Cholestasis / Q000000981:diagnostic imaging; D003251:Constriction, Pathologic; D019160:Endosonography / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D010183:Pancreatic Ducts / Q000000981:diagnostic imaging*; D010195:Pancreatitis / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012008:Recurrence