title: Targeted sonography for small hepatocellular carcinoma discovered by CT or MRI: factors affecting sonographic detection.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the detection rate of targeted sonography for small (<or= 3 cm) hepatocellular carcinomas (HCCs) primarily discovered by CT or MRI and to assess factors affecting lesion visibility on targeted sonography.
  
  
  METHODS
  Between October 2005 and April 2008, targeted sonography for small (<or= 3 cm) HCC was prospectively performed in cirrhotic patients. Targeted sonography was performed by a radiologist with knowledge of the size and location of the HCC. Invisible HCCs were compared with visible HCCs with regard to size, distance from the diaphragm, segmental location, subcapsular location, cause of liver cirrhosis, presence or absence of previous treatment, Child-Pugh class, and serum alpha-fetoprotein by using univariate and multivariate analyses.
  
  
  RESULTS
  A total of 93 consecutive patients (65 men and 28 women; mean age, 59 years) with 93 HCCs (mean size +/- SD, 1.8 +/- 0.6 cm) were enrolled in this study. Of those, 73 (78.5%) HCCs were visible on targeted sonography. The detection rate was 36.4% (4/11) for HCC <or= 1.0 cm, 77.6% (38/49) for HCC between 1.1 and 2.0 cm, and 93.9% (31/33) for HCC between 2.1 and 3.0 cm. In both univariate and multivariate analyses, the size of the tumor and distance between the tumor and the diaphragm were statistically significant factors affecting sonographic visibility.
  
  
  CONCLUSIONS
  The overall detection rate for small (<or= 3 cm) HCC on targeted sonography was 78.5%. Small size and subphrenic location of the tumor were two independent predictors of sonographic invisibility.
authors.affiliation: Department of Radiology and Research Institute of Biomedical Science, Konkuk University School of Medicine, 4-12 Hwayang-dong, Gwangjin-gu, Seoul 143-729, South Korea.
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Young Jun
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hee Sun
authors.initials: HS
authors.lastname: Park
authors.forename: Nam C
authors.initials: NC
authors.lastname: Yu
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Jung
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: Ko
authors.forename: Hae Jeong
authors.initials: HJ
authors.lastname: Jeon
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*