title: Focal hypoechoic tumors of Fatty liver: characterization of conventional and contrast-enhanced ultrasonography.
abstract: OBJECTIVE
  The purpose of this study was to investigate the characteristics of focal hypoechoic tumors of fatty liver using conventional ultrasonography and contrast-enhanced ultrasonography (CEUS).
  
  
  METHODS
  Sixty-four hypoechoic tumors of fatty liver in 52 patients were examined by both conventional ultrasonography and CEUS. Contrast pulse sequencing and a sulfur hexafluoride contrast agent were used for CEUS. The enhancement patterns were evaluated in real time. Results. Hypoechoic tumors of fatty liver showed posterior echo enhancement, including 71.4% (25 of 35) of hemangiomas, 73.3% (11 of 15) of metastases, and 50.0% (3 of 6) of hepatocellular carcinomas (HCCs) on conventional ultrasonography. During the early arterial phase, 62.5% (5 of 8) of focal nodular hyperplasia lesions showed a central spoked wheel enhancement pattern, whereas the remaining 37.5% (3 of 8) showed eccentric spoked wheel enhancement. During the arterial phase, 97.1% (34 of 35) of hemangiomas showed peripheral enhancement and centripetal fill-in, including ringlike peripheral enhancement (12 of 35), small nodular peripheral enhancement (19 of 35), and massive irregular peripheral enhancement (3 of 35). In total, 76.5% (26 of 34) of hemangiomas were completely filled in. All HCCs showed complete enhancement from 9 to 24 seconds during the arterial phase and began to wash out from 21 to 114 seconds. During the arterial phase, 40.0% (6 of 15) of metastases showed ringlike enhancement; 26.7% (4 of 15) showed slight hyperenhancement; 13.3% (2 of 15) showed hyperenhancement quickly; and the remaining 20.0% (3 of 15) showed heterogeneous hyperenhancement. All metastatic tumors began to wash out from 25 to 40 seconds. In total, 92.2% (59 of 64) of focal hypoechoic tumors of fatty liver were diagnosed as the correct pathologic type with CEUS.
  
  
  CONCLUSIONS
  With CEUS, characterization of hypoechoic tumors of fatty liver is greatly improved.
authors.affiliation: Department of Ultrasound, First Hospital of Shanxi Medical University, Taiyuan, China. liuliping1600@sina.com
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Liu
authors.forename: Bao-Wei
authors.initials: BW
authors.lastname: Dong
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Yu
authors.forename: Ping
authors.initials: P
authors.lastname: Liang
authors.forename: Da-Kun
authors.initials: DK
authors.lastname: Zhang
authors.forename: Li-Chun
authors.initials: LC
authors.lastname: An
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005234:Fatty Liver / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010743:Phospholipids; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014463:Ultrasonography / Q000379:methods*
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride