title: Contrast-enhanced harmonic endoscopic ultrasound in solid lesions of the pancreas: results of a pilot study.
abstract: OBJECTIVE
  Distinguishing pancreatic adenocarcinoma from other pancreatic masses remains challenging with current imaging techniques. This prospective study aimed to evaluate the accuracy of a new procedure, imaging the microcirculation pattern of the pancreas by contrast-enhanced harmonic endoscopic ultrasound (CEH-EUS) with a new Olympus prototype echo endoscope.
  
  
  METHODS
  35 patients presenting with solid pancreatic lesions were prospectively enrolled. All patients had conventional B mode and power Doppler EUS. After an intravenous bolus injection of 2.4 ml of a second-generation ultrasound contrast agent (SonoVue) CEH-EUS was then performed with a new Olympus prototype echo endoscope (xGF-UCT 180). The microvascular pattern was compared with the final diagnosis based on the pathological examination of specimens from surgery or EUS-guided fine-needle aspiration (EUS-FNA) or on follow-up for at least 12 months.
  
  
  RESULTS
  The final diagnoses were: 18 adenocarcinomas, 9 neuroendocrine tumors, 7 chronic pancreatitis, and 1 stromal tumor. Power Doppler failed to display microcirculation, whereas harmonic imaging demonstrated it in all cases. Out of 18 lesions with a hypointense signal on CEH-EUS, 16 were adenocarcinomas. The sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and accuracy of hypointensity for diagnosing pancreatic adenocarcinoma were 89 %, 88 %, 88 %, 89 %, and 88.5 %, compared with corresponding values of 72 %, 100 %, 77 %, 100 %, and 86 % for EUS-FNA. Of five adenocarcinomas with false-negative results at EUS-FNA, four had a hypointense echo signal at CEH-EUS.
  
  
  CONCLUSIONS
  CEH-EUS with the new Olympus prototype device successfully visualizes the microvascular pattern in pancreatic solid lesions, and may be useful for distinguishing adenocarcinomas from other pancreatic masses.
authors.affiliation: Department of Gastroenterology, Hôpital Privé Jean Mermoz, Lyon, France. dr.napoleon@wanadoo.fr
authors.forename: B
authors.initials: B
authors.lastname: Napoleon
authors.forename: M V
authors.initials: MV
authors.lastname: Alvarez-Sanchez
authors.forename: R
authors.initials: R
authors.lastname: Gincoul
authors.forename: B
authors.initials: B
authors.lastname: Pujol
authors.forename: C
authors.initials: C
authors.lastname: Lefort
authors.forename: V
authors.initials: V
authors.lastname: Lepilliez
authors.forename: M
authors.initials: M
authors.lastname: Labadie
authors.forename: J C
authors.initials: JC
authors.lastname: Souquet
authors.forename: P E
authors.initials: PE
authors.lastname: Queneau
authors.forename: J Y
authors.initials: JY
authors.lastname: Scoazec
authors.forename: J A
authors.initials: JA
authors.lastname: Chayvialle
authors.forename: T
authors.initials: T
authors.lastname: Ponchon
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D021441:Carcinoma, Pancreatic Ductal / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D003287:Contrast Media; D019160:Endosonography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging / Q000601:surgery; D010179:Pancreas / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D010182:Pancreatic Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D010865:Pilot Projects; D011446:Prospective Studies
chemical_list: D003287:Contrast Media