title: Detection and differential diagnosis of hepatic masses using pulse inversion harmonic imaging during the liver-specific late phase of contrast enhancement with Levovist.
abstract: OBJECTIVE
  The purpose of this study was to investigate whether late-phase pulse inversion harmonic imaging (PIHI) increases conspicuity in hepatic masses, helps to differentiate benign from malignant lesions, and demonstrates a greater number of and smaller metastatic lesions than do conventional (fundamental) sonography and helical CT.
  
  
  METHODS
  Thirty patients (17 women and 13 men; age range, 35-77 years; mean age, 54 years) with known or suspected liver masses were evaluated using both fundamental sonography and contrast-enhanced PIHI during the liver-specific late phase of Levovist. The patients also underwent contrast-enhanced triphasic helical CT examinations within 1 week after sonography. In 4 of the patients, gadolinium-enhanced MRI was also performed as a part of their clinical work-up.
  
  
  RESULTS
  The increase in the lesions' conspicuity on PIHI compared with fundamental sonography was significantly greater in malignant lesions than in benign lesions (p< 0.001). An echogenic rim was observed on PIHI in 8 (53%) of 15 malignant lesions. The mean number of metastatic lesions visualized on PIHI (5.5 +/- 5.3) was significantly higher than the mean number visualized on fundamental sonography (2.5 +/- 2.1, p < 0.05). Although lesions as small as 3 mm were observed on PIHI, the mean sizes of the smallest lesions demonstrated using fundamental sonography, PIHI, and helical CT were not significantly different.
  
  
  CONCLUSIONS
  Late-phase PIHI is a useful technique for characterizing hepatic lesions and demonstrating both a greater number of and smaller metastases. It may help to differentiate benign from malignant liver masses and may obviate unnecessary and expensive further imaging.
authors: Department of Radiology, Gazi University School of Medicine, Beşevler 06510, Ankara, Turkey.
authors: Cem
authors: C
authors: Yücel
authors: Hakan
authors: H
authors: Ozdemir
authors: Safiye
authors: S
authors: Gürel
authors: Sule
authors: S
authors: Ozer
authors: Mehmet
authors: M
authors: Araç
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011134:Polysaccharides; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000379:methods
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508