title: Characterization of focal liver lesions in real time using harmonic imaging with high mechanical index and contrast agent levovist.
abstract: OBJECTIVE
  The aim of this study was to characterize focal hepatic lesions using agent detection imaging and Levovist.
  
  
  METHODS
  Sixty-five patients (21 male and 44 female; age range, 8-82 years; mean +/- standard deviation, 58.1 +/- 14.5 years) were independently evaluated by two observers in a blinded manner using stored sonographic images. Seventy-five lesions were found: 15 hepatocellular carcinomas, nine focal nodular hyperplasias, two adenomas, 21 hemangiomas, 23 metastases, and five regenerative nodules. Nine patients were excluded (six because of technical failures, three with unproven diagnoses). New high-mechanical-index software was used to reveal power harmonic responses from contrast microbubble destruction. After a venous bolus injection of 4 g of Levovist at a strength of 400 mg/mL, delayed imaging was used to study lesion enhancement in the arterial, portal, and parenchymal phases. Two comparisons were made. The first was between the B-mode image and the first contrast-enhanced image after the flash. The second was between color Doppler sonograms and real-time contrast-enhanced perfusion images.
  
  
  RESULTS
  Contrast-enhanced images after the flash and real-time contrast-enhanced images revealed more information for the characterization of the lesion than did gray-scale and color Doppler images (p < 0.0001, Wilcoxon's signed rank test). Different types of lesions showed statistically significant differences in enhancement during each of the three vascular phases (p < 0.005, Kruskal-Wallis test). Lesions with lower contrast enhancement were metastases and regenerating nodules. Good agreement was present between the two observers; differences were not statistically significant (p > 0.05).
  
  
  CONCLUSIONS
  Agent detection imaging with Levovist increased diagnostic confidence in the characterization of focal hepatic lesions as compared with standard sonography.
authors.affiliation: Sardinian Mediterranean Imaging Research Group, Via Gorizia no. 11, Sassari 07100, Sardinia, Italy. vmigale@tin.it
authors.forename: V
authors.initials: V
authors.lastname: Migaleddu
authors.forename: G
authors.initials: G
authors.lastname: Virgilio
authors.forename: D
authors.initials: D
authors.lastname: Turilli
authors.forename: M
authors.initials: M
authors.lastname: Conti
authors.forename: G
authors.initials: G
authors.lastname: Campisi
authors.forename: N
authors.initials: N
authors.lastname: Canu
authors.forename: D
authors.initials: D
authors.lastname: Sirigu
authors.forename: I
authors.initials: I
authors.lastname: Vincentelli
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011134:Polysaccharides; D016037:Single-Blind Method; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508