title: Contrast-enhanced ultrasonographic findings of hepatic paragonimiasis.
abstract: OBJECTIVE
  To investigate the features of hepatic paragonimiasis on contrast-enhanced ultrasound (CEUS) imaging.
  
  
  METHODS
  Fifteen patients with hepatic paragonimiasis who were admitted to our hospital between March 2008 and August 2012 were enrolled to this study. The conventional ultrasound and CEUS examinations were performed with a Philips IU22 scanner with a 1-5-MHz convex transducer. After conventional ultrasound scanning was completed, the CEUS study was performed. Pulse inversion harmonic imaging was used for CEUS. A bolus injection of 2.4 mL of a sulfur hexafluoride-filled microbubble contrast agent (SonoVue) was administered. CEUS features were retrospectively reviewed and correlated with pathological findings.
  
  
  RESULTS
  In total, 16 lesions were detected on CEUS. The mean size of the lesions was 4.4 ± 1.6 cm (range, 1.7-6.6 cm). Subcapsular location was found in 12 lesions (75%). All the lesions were hypoechoic. Six lesions (37.5%) were of mixed content, seven (43.8%) were solid with small cystic areas, and the other three (18.8%) were completely solid. Ten lesions (62.5%) were rim enhanced with irregular tract-like nonenhanced internal areas. Transient wedge-shaped hyperenhancement of the surrounding liver parenchyma was seen in seven lesions (43.8%). Areas with hyper- or iso-enhancement in the arterial phase showed contrast wash-out and appeared hypoenhanced in the late phase. The main pathological findings included: (1) coagulative or liquefactive necrosis within the lesion, infiltration of a large number of eosinophils with the formation of chronic eosinophilic abscesses and sporadic distribution of Charcot-Leyden crystals; and (2) hyperplasia of granulomatous and fibrous tissue around the lesion.
  
  
  CONCLUSIONS
  Subcapsular location, hypoechogenicity, rim enhancement and tract-like nonenhanced areas could be seen as the main CEUS features of hepatic paragonimiasis.
authors.affiliation: Department of Ultrasound, Chinese Evidence-Based Medicine Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan Province, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Lu
authors.forename: Wen-Wu
authors.initials: WW
authors.lastname: Ling
authors.forename: Lin
authors.initials: L
authors.lastname: Ma
authors.forename: Zi-Xing
authors.initials: ZX
authors.lastname: Huang
authors.forename: Chang-Li
authors.initials: CL
authors.lastname: Lu
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D010237:Paragonimiasis / Q000175:diagnosis / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D013459:Sulfur Hexafluoride / Q000494:pharmacology; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D013459:Sulfur Hexafluoride
keywords: Contrast-enhanced ultrasonography; Infection; Liver; Paragonimiasis