title: Potential of electron beam computed tomography for coronary artery calcium screening to evaluate fatty liver: comparison with 1H magnetic resonance spectroscopy in the Dallas Heart Study.
abstract: OBJECTIVE
  Electron beam computed tomography (EBCT) for coronary artery calcification can potentially evaluate liver fat, another marker of cardiovascular risk. We compared quantitative estimates of hepatic steatosis measured by EBCT with those obtained by a well-validated, accurate-measure, magnetic resonance spectroscopy ((1)H MRS).
  
  
  METHODS
  EBCT and (1)H MRS were performed in 2159 subjects from the Dallas Heart Study. Forty subjects were randomly selected from each of 5 subgroups of liver fat percent by (1)H MRS (n = 200). EBCT average liver attenuation (HU) was determined in a 1- to 2-cm circular region of interest over the liver lobes. Pearson correlation coefficients were calculated. Using a previously defined (1)H MRS hepatic steatosis cut point (>5.5%), an optimized EBCT liver attenuation cut point was determined by receiver operating characteristic analysis.
  
  
  RESULTS
  (1)H MRS liver fat content and EBCT average right lobe liver attenuation were moderately negatively correlated (r = -0.64, P < 0.0001) in all subjects and in those with (1)H MRS hepatic steatosis (r = -0.71, P < 0.0001). This correlation did not improve with attenuation correction of the EBCT data using a standard calcium phantom or statistical transformation. Using an optimized receiver operating characteristic EBCT cut point (64.5 HU), sensitivity was 78% and specificity was 72% for detecting (1)H MRS hepatic steatosis, with a high false negative rate. Risk factors for hepatic steatosis (obesity, diabetes mellitus, insulin resistance, metabolic syndrome) were more strongly correlated with (1)H MRS than EBCT liver fat measures.
  
  
  CONCLUSIONS
  Liver attenuation on EBCT acquired for coronary artery calcification screening correlates modestly with (1)H MRS measures of liver fat content, with a high false negative rate.
authors: Department of Internal Medicine, Division of Cardiology, The University of Texas Southwestern Medical Center at Dallas, 75390-9047, USA. Susan.Matulevicius@UTSouthwestern.edu
authors: Susan
authors: S
authors: Matulevicius
authors: Laura C
authors: LC
authors: Huff
authors: Lidia S
authors: LS
authors: Szczepaniak
authors: Colby R
authors: CR
authors: Ayers
authors: Matthew
authors: M
authors: Budoff
authors: Roderick
authors: R
authors: McColl
authors: Amit
authors: A
authors: Khera
authors: Ronald M
authors: RM
authors: Peshock
mesh_terms: D000328:Adult; D002114:Calcinosis / Q000175:diagnosis* / Q000473:pathology; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000473:pathology; D015331:Cohort Studies; D003331:Coronary Vessels / Q000473:pathology*; D005188:False Negative Reactions; D005234:Fatty Liver / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013781:Texas; D014057:Tomography, X-Ray Computed / Q000379:methods*