title: Contrast-enhanced harmonic endoscopic ultrasonography in the differential diagnosis of gallbladder wall thickening.
abstract: OBJECTIVE
  Differentiation of gallbladder (GB) carcinoma from benign GB wall thickening is challenging. The recent introduction of second-generation ultrasonic contrast agents has made contrast harmonic imaging with EUS possible. The aim of our study was to evaluate the utility of contrast-enhanced harmonic EUS (CH-EUS) for the differential diagnosis of GB wall thickening.
  
  
  METHODS
  Thirty-six consecutive patients with GB wall thickening imaged by CH-EUS and then underwent surgery were enrolled in this study. After the lesions were observed with conventional harmonic EUS (H-EUS), CH-EUS was performed with intravenous injection of 0.015 ml/kg of Sonazoid. Three reviewers with various levels of experience of EUS (Reviewer A: experienced endosonographer, B: EUS trainee, C: experienced gastroenterologist with expertise in transabdominal ultrasound but no EUS experience) were blinded to findings of recorded video of H-EUS and CH-EUS. The diagnostic accuracy of H-EUS and CH-EUS for malignant GB wall thickening was compared.
  
  
  RESULTS
  Final diagnoses based on surgical histology were GB carcinoma in 16, cholecystitis in 11, adenomyomatosis in 6 and cholesterolosis in 3. Overall sensitivity, specificity and accuracy for diagnosing malignant GB wall thickening of H-EUS and CH-EUS were 83.3 versus 89.6, 65 versus 98% (p < 0.001) and 73.1 versus 94.4% (p < 0.001). The inter-observer agreement for H-EUS was moderate (κ = 0.51), whereas that for CH-EUS was substantial (κ = 0.77). The inhomogeneous enhanced pattern on CH-EUS was a strong predictive factor of malignant GB wall thickening.
  
  
  CONCLUSIONS
  CH-EUS has the potential to improve the preoperative diagnostic accuracy and inter-observer agreement in the differential diagnosis of GB wall thickening.
authors.affiliation: Department of Endoscopy, The Jikei University School of Medicine, 3-25-8 Nishishinbashi, Minato-ku, Tokyo, 105-8461, Japan, himazu21@aol.com.
authors.forename: Hiroo
authors.initials: H
authors.lastname: Imazu
authors.forename: Naoki
authors.initials: N
authors.lastname: Mori
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kanazawa
authors.forename: Masafumi
authors.initials: M
authors.lastname: Chiba
authors.forename: Hirobumi
authors.initials: H
authors.lastname: Toyoizumi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Torisu
authors.forename: Seita
authors.initials: S
authors.lastname: Koyama
authors.forename: Shoryoku
authors.initials: S
authors.lastname: Hino
authors.forename: Tiing Leong
authors.initials: TL
authors.lastname: Ang
authors.forename: Hisao
authors.initials: H
authors.lastname: Tajiri
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000000981:diagnostic imaging*; D003287:Contrast Media; D003937:Diagnosis, Differential; D019160:Endosonography; D005260:Female; D005290:Ferric Compounds; D005706:Gallbladder Neoplasms / Q000000981:diagnostic imaging*; D006801:Humans; D007501:Iron; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010087:Oxides; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; C069727:Sonazoid; D007501:Iron