title: Outcomes of follow-up CT for small (5-10-mm) arterially enhancing nodules in the liver and risk factors for developing hepatocellular carcinoma in a surveillance population.
abstract: OBJECTIVE
  To evaluate the outcomes of small (5-10 mm), arterially enhancing nodules (SAENs) shown exclusively at the hepatic arterial phase of CT in a hepatocellular carcinoma (HCC) surveillance population and to determine risk factors for developing HCC.
  
  
  METHODS
  The study population included 112 patients (male:female = 100:12; aged 36-92 years) with 175 SAENs who were at risk of HCC. We evaluated serial changes during follow-up (1.4-41.8 months, mean 35.7 months) and analysed the initial CT findings of SAENs and the accompanying lesions to elucidate the risk factors for HCC development.
  
  
  RESULTS
  Of 175 SAENs, 101(57.7%) disappeared and 34(19.4%) persisted. Forty SAENs (22.9%) became HCC in 33 patients (29.5%). Presence of HCC treatment history (p = 0.005, risk ratio = 7.429), a larger size of SAEN (p = 0.003, risk ratio = 1.630), presence of coexistent HCC (p = 0.021, risk ratio = 3.777) and absence of coexistent typical arterioportal shunts (p = 0.003, risk ratio = 4.459) turned out to be independently significant risk factors for future development of HCC.
  
  
  CONCLUSIONS
  SAENs were frequently seen in an HCC surveillance population and have a 22.9% probability of becoming HCC on a per-lesion basis. Risk increased particularly when the lesion was associated with a previous or concurrent HCC, a large size or found without a coexistent typical arterioportal shunt.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Irwon-dong, Gangnam-gu, Seoul, 135-710, Korea.
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Park
authors.forename: Young-Sun
authors.initials: YS
authors.lastname: Kim
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Hyo K
authors.initials: HK
authors.lastname: Lim
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Rhim
authors.forename: Jongmee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000000981:diagnostic imaging*; D002908:Chronic Disease; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000000981:diagnostic imaging*; D008107:Liver Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008113:Liver Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome