title: Comparison of clinical MRI liver iron content measurements using signal intensity ratios, R2and R2.
abstract: To compare three types of MRI liver iron content (LIC) measurement performed in daily clinical routine in a single center over a 6-year period.
  
  
  
  Patients undergoing LIC MRI-scans (1.5T) at our center between January 1, 2008 and December 31, 2013 were retrospectively included. LIC was measured routinely with signal intensity ratio (SIR) and MR-relaxometry (R2and R2*) methods. Three observers placed regions-of-interest. The success rate was the number of correctly acquired scans over the total number of scans. Interobserver agreement was assessed with intraclass correlation coefficients (ICC) and Bland-Altman analysis, correlations between LICSIR, R2, R2*, and serum values with Spearman's rank correlation coefficient. Diagnostic accuracies of LICSIR, R2and serum transferrin, transferrin-saturation, and ferritin compared to increased R2* (≥44 Hz) as indicator of iron overload were assessed using ROC-analysis.
  
  
  
  LIC MRI-scans were performed in 114 subjects. SIR, R2, and R2* data were successfully acquired in 102/114 (89%), 71/114 (62%), and 112/114 (98%) measurements, with the lowest success rate for R2. The ICCs of SIR, R2, and R2* did not differ at 0.998, 0.997, and 0.999. R2and serum ferritin had the highest diagnostic accuracies to detect elevated R2* as mark of iron overload.
  
  
  
  SIR and R2* are preferable over R2in terms of success rates. R2*'s shorter acquisition time and wide range of measurable LIC values favor R2* over SIR for MRI-based LIC measurement.
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands. j.h.runge@amc.uva.nl.
authors.forename: Jurgen H
authors.identifier: 0000-0003-4190-3890
authors.initials: JH
authors.lastname: Runge
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
authors.forename: Erik M
authors.initials: EM
authors.lastname: Akkerman
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
authors.forename: Marian A
authors.initials: MA
authors.lastname: Troelstra
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
authors.forename: Aart J
authors.initials: AJ
authors.lastname: Nederveen
authors.affiliation: Department of Gastroenterology & Hepatology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Beuers
authors.affiliation: Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands.
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D019190:Iron Overload / Q000000981:diagnostic imaging*; D008099:Liver / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014168:Transferrin / Q000378:metabolism
chemical_list: D015415:Biomarkers; D014168:Transferrin; D005293:Ferritins
keywords: Biomarker; Blood transfusion; Hemochromatosis; Iron overload; Magnetic resonance imaging; Relaxometry