title: Characterization of intra-abdominal lesions of undetermined origin by contrast-enhanced harmonic EUS (with videos).
abstract: BACKGROUND
  The diagnosis of intra-abdominal lesions of undetermined origin is often a challenge for endoscopists and radiologists.
  
  
  OBJECTIVE
  To evaluate the microvasculature of benign and malignant intra-abdominal lesions by contrast-enhanced harmonic EUS (CEH-EUS) and to investigate its usefulness for discriminating between malignant and benign lesions.
  
  
  METHODS
  The vascularity of intra-abdominal lesions of undetermined origin was observed by using CEH-EUS. The lesions were classified according to their vascular patterns. The effectiveness of CEH-EUS in differentiating malignant from benign lesions was evaluated.
  
  
  METHODS
  Kinki University School of Medicine, Osaka, Japan.
  
  
  METHODS
  Forty-three patients, each with a lesion of undetermined origin, were evaluated prospectively by CEH-EUS between March 2007 and March 2009.
  
  
  METHODS
  CEH-EUS was performed by using a prototype echoendoscope and the extended pure harmonic detection mode (a specific mode for contrast harmonic imaging).
  
  
  METHODS
  The lesions were categorized by 2 physicians as having no, homogeneous, or heterogeneous enhancement. A consensus was reached for each case offline. How the benign and malignant groups differed in terms of their enhancement patterns was examined.
  
  
  RESULTS
  The kappa coefficient of the interobserver agreement test was 0.953 (P < .001). Of the 27 malignant lesions, 26 (96.3%) exhibited heterogeneous enhancement. The 1 remaining malignant lesion (3.7%) showed homogeneous enhancement. Of the 16 benign lesions, none displayed heterogeneous enhancement, and 12 (75%) and 4 (25%) exhibited homogeneous and no enhancement, respectively. The malignant and benign lesion groups differed significantly in terms of homogeneous and heterogeneous enhancement (P < .001). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy with which CEH-EUS differentiated malignant from benign lesions were 96.3%, 100%, 100%, 94.1%, and 97.6%, respectively.
  
  
  CONCLUSIONS
  A single medical unit with a limited number of patients.
  
  
  CONCLUSIONS
  CEH-EUS depicted the microvasculature of intra-abdominal lesions of undetermined origin very clearly and may be useful for characterizing such lesions.
authors.affiliation: Department of Gastroenterology and Hepatology, Kinki University School of Medicine, Osaka, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Xia
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kitano
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kudo
authors.forename: Hajime
authors.initials: H
authors.lastname: Imai
authors.forename: Ken
authors.initials: K
authors.lastname: Kamata
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sakamoto
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Komaki
mesh_terms: D000008:Abdominal Neoplasms / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D019160:Endosonography / Q000295:instrumentation*; D005260:Female; D005290:Ferric Compounds; D006801:Humans; D007089:Image Enhancement; D007501:Iron; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D015588:Observer Variation; D010087:Oxides; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D018084:Ultrasonography, Interventional / Q000295:instrumentation
chemical_list: D003287:Contrast Media; D005290:Ferric Compounds; D010087:Oxides; C069727:Sonazoid; D007501:Iron