title: Hypoechoic focal liver lesions: characterization with contrast enhanced ultrasonography.
abstract: OBJECTIVE
  To evaluate the late sinusoidal phase of contrast enhancement with a 2nd-generation ultrasound contrast enhanced medium in the characterization of hypoechoic focal liver lesions.
  
  
  METHODS
  We studied 88 hypoechoic liver lesions (diameter range, 1-18 cm; with 18 lesions 2 cm or less) found on conventional grayscale sonography (US) with contrast-enhanced ultrasonography (CEUS). Final diagnosis was made using contrast enhanced helical CT, contrast enhanced MR, angiography (DSA), and/or histopathic confirmation or clinical imaging follow-up.
  
  
  RESULTS
  There were 37/88 benign lesions demonstrated: 17 cavernous hemangiomas, 3 capillary hemangiomas, 11 focal nodular hyperplasias (FNH), 3 focal areas of sparing in hepatic steatosis, 2 adenomas, and 1 intrahepatic necrotic area. Malignant lesions demonstrated included 51/88: 27 hepatocellular carcinomas (HCC) in cirrhosis, 11 metastatic carcinomas, 10 metastatic endocrine tumors, 2 cholangiocellular carcinomas (CCC) and 1 non-Hodgkin's lymphoma (NHL). CEUS characterized 30/37 (81%) benign lesions and 45/51 (88%) malignant lesions. On the basis of the results obtained during the sinusoidal contrast enhanced phase of CEUS, diagnosis of benignancy was possible in 35/37 (95%) of benign liver lesions and diagnosis of malignancy in 49/51 (96%) of malignant liver lesions. The enhancement pattern of 13 small (< or = 2 cm in diameter) hypervascular liver lesions (3 capillary hemangiomas, 2 FNHs, 4 HCCs, 4 metastatic endocrine tumors) was better demonstrated on CEUS than on helical CT. In these cases the hyper vascularization of the lesions shown on CEUS was not confirmed on CT.
  
  
  CONCLUSIONS
  CEUS distinguished malignant from benign hypoechoic liver lesions with an accuracy of 95%.
authors.affiliation: Department of Radiology, Policlinico G.B. Rossi, University of Verona, Italy.
authors.forename: Mirko
authors.initials: M
authors.lastname: D'Onofrio
authors.forename: Umberto
authors.initials: U
authors.lastname: Rozzanigo
authors.forename: Bianca Maria
authors.initials: BM
authors.lastname: Masinielli
authors.forename: Sabrina
authors.initials: S
authors.lastname: Caffarri
authors.forename: Andrea
authors.initials: A
authors.lastname: Zogno
authors.forename: Roberto
authors.initials: R
authors.lastname: Malagò
authors.forename: Carlo
authors.initials: C
authors.lastname: Procacci
mesh_terms: D015901:Angiography, Digital Subtraction; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D010743:Phospholipids / Q000008:administration & dosage*; D011446:Prospective Studies; D013459:Sulfur Hexafluoride / Q000008:administration & dosage*; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride