title: Accuracy of contrast-enhanced harmonic EUS with a second-generation perflutren lipid microsphere contrast agent (with video).
abstract: BACKGROUND
  EUS-FNA has limitations in cancer diagnosis/staging. New contrast agents, transducers, and processors have improved the potential of contrast-enhanced harmonic (CEH)-EUS.
  
  
  OBJECTIVE
  To determine optimal settings and preliminary accuracy of CEH-EUS by using a second-generation perflutren lipid microsphere contrast agent and a prototype linear echoendoscope.
  
  
  METHODS
  Prospective, comparative, pilot study.
  
  
  METHODS
  Tertiary-care medical center.
  
  
  METHODS
  This study involved patients with esophageal/pancreatic/liver tumors or adenopathy.
  
  
  METHODS
  Contrast agent was injected (10 μL/kg intravenously in 1-2 doses), and the mechanical index was optimized over 5 cases (0.3). Intermittent/continuous imaging was used with extended pure harmonic detection.
  
  
  METHODS
  Before-contrast and after-contrast predictions of neoplasia (5-point Likert scale). The reference standard was positive tissue or 6-month follow-up. Perfusion factors (sequence, pattern, washout) were noted, and phases were video recorded (arterial, venous, and postvenous).
  
  
  RESULTS
  Thirty sites (7 nodes and 16 pancreatic and 7 nonpancreatic masses) were imaged in 21 patients; 21 of 30 had FNA, and 5 had surgery. Four cases (13.3%) were rated as undecided/indeterminate with EUS (vs 1 [3.3%] with CEH-EUS; P = .35). Twenty-four cases with confirmed diagnoses (12 malignant and 12 benign) were used for test performance: positive/negative predictive values for CEH-EUS were 80.0% (95% confidence interval, 51.9%-95.7%)/100.0% (95% confidence interval, 63.0%-100.0%) versus 84.6%/100.0% for EUS. Accuracies, counting "undecided" (1 in CEH-EUS and 4 in EUS) as incorrect, were 83.3% and 79.2%. In 2 cases, management would change significantly: (1) liver hemangioma, avoiding FNA; and (2) mediastinal "cyst" confirmed as solid.
  
  
  CONCLUSIONS
  Small sample. Tissue not always available.
  
  
  CONCLUSIONS
  CEH-EUS adds minimal imaging time and is accurate, with small improvement over EUS. Added information in vascular and cystic lesions can potentially change management.
authors.affiliation: Department of Medicine, Digestive Disease Center, Medical University of South Carolina, Charleston, South Carolina 29425, USA. romagnuo@musc.edu
authors.forename: Joseph
authors.initials: J
authors.lastname: Romagnuolo
authors.forename: Brenda
authors.initials: B
authors.lastname: Hoffman
authors.forename: Stacie
authors.initials: S
authors.lastname: Vela
authors.forename: Robert
authors.initials: R
authors.lastname: Hawes
authors.forename: Shivakumar
authors.initials: S
authors.lastname: Vignesh
mesh_terms: D044963:Biopsy, Fine-Needle; D003287:Contrast Media; D019160:Endosonography / Q000379:methods*; D004938:Esophageal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D005466:Fluorocarbons; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008055:Lipids; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D008206:Lymphatic Diseases / Q000000981:diagnostic imaging / Q000473:pathology; D008863:Microspheres; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology; D010865:Pilot Projects; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D005466:Fluorocarbons; D008055:Lipids; C042852:perflutren