title: Quantification of hepatic steatosis: a comparison of computed tomography and magnetic resonance indices in candidates for living liver donation.
abstract: OBJECTIVE
  To evaluate, in a group of candidates for liver donation, the role of unenhanced computed tomography (CT) and magnetic resonance (MR) as noninvasive means to measure hepatic steatosis (HS).
  
  
  METHODS
  Sixty-one consecutive candidates underwent CT and MR evaluation for liver donation within 3 weeks of liver biopsy. On CT, three methods of HS quantification were evaluated: the measurement of hepatic attenuation (CT L), the ratio of hepatic attenuation to splenic attenuation (CT L/S), and the difference between the hepatic and splenic attenuation (CT L-S). On MR, HS was reported in terms of fat signal fraction (FSF) using in-phase/opposed-phase and fat/non-fat- saturated images, with and without normalization with the spleen (T1W IP/OP FSF, T1W IP/OP FSF spleen and T2W ± FS FSF, TW2 ± FS FSF spleen). The accuracy of each imaging index in the diagnosis of HS, according to various thresholds, was assessed using receiver operating characteristic analysis.
  
  
  RESULTS
  On biopsy, 35 donors showed no significant HS (<5%); the remaining 26 showed HS ranging from 5% to 40%. With all CT and MR indices, there was a trend toward increasing diagnostic accuracy as the threshold levels of HS increased. When comparing all the indices, TW2 ± FS FSF(spl) showed higher accuracy at threshold levels of 5% and 10% of steatosis but without reaching statistical significance.
  
  
  CONCLUSIONS
  In candidates for living donation, MR and CT indices are similar in estimating liver-fat content; however, MR with T2W ± FS FSF(spl) sequences shows higher accuracy when low threshold levels of steatosis (≤5% and ≤10% HS) are selected.
authors.affiliation: Diagnostic and Therapeutic Services, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Via Tricomi 5, Palermo, 90127 Italy. Electronic address: lmaruzzelli@ismett.edu.
authors.forename: Luigi
authors.initials: L
authors.lastname: Maruzzelli
authors.affiliation: University of Pittsburgh School of Medicine, Pittsburgh, PA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Parr
authors.affiliation: Diagnostic and Therapeutic Services, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Via Tricomi 5, Palermo, 90127 Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Miraglia
authors.affiliation: Department of Information Technology, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Palermo, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Tuzzolino
authors.affiliation: Diagnostic and Therapeutic Services, Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT), Via Tricomi 5, Palermo, 90127 Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Luca
mesh_terms: D000293:Adolescent; D000328:Adult; D005234:Fatty Liver / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016031:Liver Transplantation / Q000379:methods*; D019520:Living Donors; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
keywords: Liver; biopsy; computed tomography; magnetic resonance; steatosis; transplant