title: 1.5 Harmonic Imaging Sonography with microbubble contrast agent improves characterization of hepatocellular carcinoma.
abstract: OBJECTIVE
  To investigate the usefulness of 1.5 Harmonic Imaging Sonography with the use of the contrast agent Levovist for the diagnosis of hepatocellular carcinoma (HCC) and for the evaluation of therapeutic response.
  
  
  METHODS
  Phantom experiments were performed to compare the contrast effects of 2(nd) harmonic imaging and 1.5 Harmonic Imaging Sonography. 1.5 Harmonic Imaging Sonography was employed to examine 36 patients with HCC (42 nodules) before and after the treatment and to compare against the findings obtained using other diagnostic imaging modalities.
  
  
  RESULTS
  In 1.5 Harmonic Imaging Sonography, the tumor vessels of HCCs were clearly identified during the early phase, and late-phase images clearly demonstrated the differences in contrast enhancement between the tumor and surrounding hepatic parenchyma. Blood flow within the tumor was detected in 36 nodules (85.7%) during the early phase and in all 42 nodules (100%) during the late phase using 1.5 Harmonic Imaging Sonography, in 38 nodules (90.5%) using contrast-enhanced CT, in 34 nodules (81.0%) using digital subtraction angiography (DSA), and in 42 nodules (100%) using US CO(2) angiography. Following transcatheter arterial embolization, 1.5 Harmonic Imaging Sonography detected blood flow and contrast enhancement within the tumors that were judged to contain viable tissue in 20 of 42 nodules (47.6%). However, 6 of these 10 cases were not judged in contrast-enhanced CT. 1.5 Harmonic Imaging Sonography was compared with the US CO(2) angiography findings as the gold standard, and the sensitivity and specificity of these images for discerning viable and nonviable HCC after transcatheter arterial embolization were 100% and 100%, respectively.
  
  
  CONCLUSIONS
  1.5 Harmonic Imaging Sonography permits the vascular structures of HCCs to be identified and blood flow within the tumor to be clearly demonstrated. Furthermore, 1.5 Harmonic Imaging Sonography is potentially useful for evaluating the therapeutic effects of transcatheter arterial embolization on HCC.
authors.affiliation: First Department of Internal Medicine, Mie University School of Medicine, 2-174 Edobashi, Tsu, Mie 514-8507, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Katsuya
authors.initials: K
authors.lastname: Shiraki
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakanishi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Fuke
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakano
authors.forename: Akira
authors.initials: A
authors.lastname: Hashimoto
authors.forename: Atsuya
authors.initials: A
authors.lastname: Shimizu
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Hamataki
mesh_terms: D000328:Adult; D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D011134:Polysaccharides; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508