title: Automatic T2* determination for quantification of iron load in heart and liver: a comparison between automatic inline Maximum Likelihood Estimate and the truncation and offset methods.
abstract: OBJECTIVE
  To validate ironload T2* by automatic inline Maximum Likelihood Estimate (MLE) with k-space Rician noise correction, against the manual and automated truncation, as well as offset methods, in phantoms and in heart and liver in patients.
  
  
  METHODS
  Twenty-five patients and an iron-oxide phantom were scanned at 1.5T using 2 multi-echo gradient-echo sequences. All parameters were identical (voxel 2-3 × 2-3 × 10 mm3, 10 echoes, TR = 26 ms, FA = 20°, BW = 833 Hz, SENSE = 2) except for TE (cardiac: TE1= 2·5 ms, ΔTE = 2·5 ms; liver: TE1= 1·2 ms, ΔTE = 1·5 ms). Phantoms were scanned at 1 and 32 signal averages (NSA), with NSA32 representing low-noise reference.
  
  
  RESULTS
  Phantoms: MLE showed low variability between NSA1 and NSA32 (0·02 ± 0·29 ms, CI ±0·21 ms). Between methods, no difference was shown (MLE versus all: <0·31 ms, CI < ±0·35 ms).
  
  
  METHODS
  No differences were found between methods in heart (MLE versus all: <-0·22 ms, CI < ±0·75 ms) or liver (MLE versus all: <0·12 ms, CI < ±0·26 ms).
  
  
  CONCLUSIONS
  The automatic inline MLE method is comparable to the general reference standards for determining cardiac and liver T2* for ironload in man. An automatic inline method may simplify ironload assessment, particularly in centres seeing fewer cases.
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.|BHF Centre of Research Excellence, NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trusts, King's College London, London, UK.
authors.forename: Erik
authors.initials: E
authors.lastname: Hedström
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.|BHF Centre of Research Excellence, NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trusts, King's College London, London, UK.|Philips Research, London, UK.
authors.forename: Tobias
authors.initials: T
authors.lastname: Voigt
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.|BHF Centre of Research Excellence, NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trusts, King's College London, London, UK.
authors.forename: Gerald
authors.initials: G
authors.lastname: Greil
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.|BHF Centre of Research Excellence, NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trusts, King's College London, London, UK.
authors.forename: Tobias
authors.initials: T
authors.lastname: Schaeffter
authors.affiliation: Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.|BHF Centre of Research Excellence, NIHR Biomedical Research Centre, Guy's and St Thomas' NHS Foundation Trusts, King's College London, London, UK.|Division of Cardiovascular Imaging, Goethe University, Frankfurt am Main, Germany.
authors.forename: Eike
authors.initials: E
authors.lastname: Nagel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001331:Automation; D002648:Child; D002675:Child, Preschool; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D007501:Iron / Q000032:analysis*; D019190:Iron Overload / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008099:Liver / Q000737:chemistry* / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000737:chemistry*; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D007501:Iron
keywords: algorithm; automated; heart; ironload; liver; validation