title: Characterisation of focal liver lesions with unenhanced and contrast enhanced low MI real time ultrasound: on-site unblinded versus off-site blinded reading.
abstract: OBJECTIVE
  To compare on-site and blinded off-site reading of baseline ultrasound (US) and contrast enhanced ultrasound (CEUS) for classification and characterisation of focal liver lesions.
  
  
  METHODS
  99 patients (57 women and 42 men, age range 18-89 years, mean age: 59 years) with 53 malignant and 46 benign liver lesions were studied with unenhanced US followed by contrast enhanced US after injection of 2.4 ml SonoVue® (Bracco, Milano, Italy). Image interpretation was performed on-site with clinical information available by consensus of two readers and off-site by two independent blinded readers at two different centers. Comparison of pre and post contrast scans and of the different readers was performed. Reference examinations were histology, intraoperative US, MRI or CT.
  
  
  RESULTS
  Sensitivity for malignancy improved from 81/89/66% (on-site/off-site reader 1/2) before to 100/96/96% post contrast administration (p<0.05, except for reader 1). Specificity improved from 48/48/54% on baseline US to 89/80/76% on CEUS (p<0.05). Accuracy for specific lesion diagnosis was 62/59/50% pre and 90/77/72% post contrast (p<0.05). Classification and characterisation post contrast were mildly inferior for off-site reading. Agreement between on-site and off-site readers of unenhanced scans was fair (κ=0.29-0.39) while it was good for CEUS (κ=0.63-0.79).
  
  
  CONCLUSIONS
  CEUS improves classification and characterisation of focal liver lesions and interobserver agreement compared to conventional US. Classification and characterisation post contrast were mildly but statistically significantly better for on-site than for off-site reading.
authors.affiliation: Department of Radiology and Nuclear Medicine, University Hospital Basel, University of Basel, Petersgraben 4, 4031 Basel, Switzerland. jhohmann@uhbs.ch
authors.forename: Joachim
authors.initials: J
authors.lastname: Hohmann
authors.forename: Jan
authors.initials: J
authors.lastname: Skrok
authors.forename: Raffaella
authors.initials: R
authors.lastname: Basilico
authors.forename: Manfred
authors.initials: M
authors.lastname: Jennett
authors.forename: Anja
authors.initials: A
authors.lastname: Müller
authors.forename: Karl-Jürgen
authors.initials: KJ
authors.lastname: Wolf
authors.forename: Thomas
authors.initials: T
authors.lastname: Albrecht
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D011795:Surveys and Questionnaires; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride