title: Predicting coverage of transverse subcostal sonography with the use of previous computed tomography before a sonographic liver examination: a prospective study.
abstract: OBJECTIVE
  The purpose of this study was to assess the coverage of transverse subcostal sonography in the supine position by using computed tomography (CT) performed before a sonographic liver examination as a predictor of sonographic coverage.
  
  
  METHODS
  A total of 124 patients (87 men and 37 women; mean age, 55.55 years; range, 24-79 years) who underwent abdominal CT and subsequent liver sonography were enrolled. All patients were assessed for the coverage of transverse subcostal sonography in the supine position by consensus of 2 radiologists. We evaluated the correlation between the level of the posterior rib against the liver dome on axial CT and a sonographic coverage scoring system using Spearman partial correlation analysis. The optimal cutoff value of the liver position and other potential factors associated with sonographic coverage were analyzed.
  
  
  RESULTS
  Among age, sex, body mass index, interposition of bowel around the gallbladder fossa, atrophic changes from cirrhotic liver, and liver position, liver position was the only independent factor associated with sonographic coverage (P < .001). Liver position and the sonographic coverage score were moderately negatively correlated, with statistical significance (r = -0.44; P < .001). The optimal cutoff value for the level of the hepatic dome was at the 10th posterior rib on axial CT.
  
  
  CONCLUSIONS
  Liver position is the only independent factor associated with the coverage of transverse subcostal sonography in the supine position. If it is above the 10th posterior rib level, we can predict difficulty in adequate sonographic coverage of the liver.
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. rhimhc@skku.edu.
authors.forename: Tae Wook
authors.initials: TW
authors.lastname: Kang
authors.forename: Hyunchul
authors.initials: H
authors.lastname: Rhim
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.forename: Wooil
authors.initials: W
authors.lastname: Kim
authors.forename: Jung Gu
authors.initials: JG
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging*; D008107:Liver Diseases / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012272:Ribs / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D014463:Ultrasonography / Q000379:methods
keywords: computed tomography; diaphragm; hepatocellular carcinoma; sonography; surveillance