title: The challenge of endoscopic ultrasonography.
authors.affiliation: University Hospitals of Cleveland, Ohio.
authors.forename: M V
authors.initials: MV
authors.lastname: Sivak
mesh_terms: D020776:Endoscopes, Gastrointestinal; D016099:Endoscopy, Gastrointestinal / Q000379:methods; D005767:Gastrointestinal Diseases / Q000175:diagnosis; D006801:Humans; D018084:Ultrasonography, Interventional / Q000295:instrumentation / Q000379:methods