title: Portal and hepatic vein thrombosis in liver abscess: CT findings.
abstract: OBJECTIVE
  Our aim is to describe imaging findings of portal and hepatic vein thrombosis in pyogenic liver abscess on contrast-enhanced MDCT and to determine the incidence and evolving patterns on follow-up imaging.
  
  
  METHODS
  Over a 5-year period, 67 patients with liver abscess underwent single-phase (n=30) or triphasic (n=37) contrast-enhanced CT. Images were reviewed for the presence of portal vein (PV) or hepatic vein (HV) thrombosis, regional parenchymal attenuation, and changes on follow-up CT.
  
  
  RESULTS
  Venous thrombosis was seen in 28/67 patients (42%), involving PV in 16/67 (24%) and HV vein in 15/67 (22%); 3/67 (4%) had both PV and HV thrombosis. Thrombosis was seen as non-enhancing linear structures without expanding the lumen in all cases. Regional parenchymal attenuation during the portal-phase was hyperattenuating (10/16, 63%) or isoattenuating (6/16, 38%) in PV thrombosis, and mostly hypoattenuating (13/15, 87%) in HV thrombosis (P<.001). Of 27 patients with follow-up contrast-enhanced CT, venous thrombosis resolved in 10/27 (37%) within 6 months and persisted in 17/27 (63%) for 3-38 months, including 13 PV thrombosis and 4 HV thrombosis. Interval parenchymal atrophy was seen only in four all with persistent PV thrombosis.
  
  
  CONCLUSIONS
  Both PV and HV thrombosis frequently occurs in liver abscess and is seen as non-enhancing linear structures without expanding the lumen on contrast-enhanced CT. Regional attenuation changes in hepatic vein thrombosis were often hypoattenuating whereas none with portal vein thrombosis showed hypoattenuation.
authors.affiliation: Department of Medical Imaging, University Health Networks and Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada. smaejaz@hotmail.com
authors.forename: Mohammed Aejaz
authors.initials: MA
authors.lastname: Syed
authors.forename: Tae Kyoung
authors.initials: TK
authors.lastname: Kim
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Jang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006502:Budd-Chiari Syndrome / Q000000981:diagnostic imaging / Q000209:etiology; D003287:Contrast Media; D005260:Female; D006801:Humans; D008100:Liver Abscess / Q000150:complications* / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed; D020246:Venous Thrombosis / Q000000981:diagnostic imaging* / Q000209:etiology
chemical_list: D003287:Contrast Media