title: Assessment of liver fat quantification in the presence of iron.
abstract: This study assesses the stability of magnetic resonance liver fat measurements against changes in T2* due to the presence of iron, which is a confound for accurate quantification. The liver T2* was experimentally shortened by intravenous infusion of a super paramagnetic iron oxide contrast agent. Low flip angle multiecho gradient echo sequences were performed before, during and after infusion. The liver fat fraction (FF) was calculated in co-localized regions-of-interest using T2* models that assumed no decay, monoexponential decay and biexponential decay. Results show that, when T2* was neglected, there was a strong underestimation of FF and with monoexponential decay there was a weak overestimation of FF. Curve-fitting using the biexponential decay was found to be problematic. The overestimation of FF may be due to remaining deficiencies in the model, although is unlikely to be important for clinical diagnosis of steatosis.
authors.affiliation: University of California San Diego, San Diego, CA 92103-8226, USA. mbydder@ucsd.edu
authors.forename: Mark
authors.initials: M
authors.lastname: Bydder
authors.forename: Masoud
authors.initials: M
authors.lastname: Shiehmorteza
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yokoo
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sugay
authors.forename: Michael S
authors.initials: MS
authors.lastname: Middleton
authors.forename: Olivier
authors.initials: O
authors.lastname: Girard
authors.forename: Michael E
authors.initials: ME
authors.lastname: Schroeder
authors.forename: Tanya
authors.initials: T
authors.lastname: Wolfson
authors.forename: Anthony
authors.initials: A
authors.lastname: Gamst
authors.forename: Claude
authors.initials: C
authors.lastname: Sirlin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003287:Contrast Media; D003430:Cross-Sectional Studies; D003911:Dextrans; D005234:Fatty Liver / Q000175:diagnosis*; D005240:Feasibility Studies; D005260:Female; D052203:Ferrosoferric Oxide; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008099:Liver / Q000473:pathology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D058185:Magnetite Nanoparticles; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D003287:Contrast Media; D003911:Dextrans; D058185:Magnetite Nanoparticles; C065507:ferumoxides; D052203:Ferrosoferric Oxide
references.citation: J Magn Reson Imaging. 1991 Sep-Oct;1(5):521-30
references.pmid: 1790376
references.citation: Magn Reson Med. 2004 Jan;51(1):35-45
references.pmid: 14705043
references.citation: Radiology. 2005 Dec;237(3):1048-55
references.pmid: 16237138
references.citation: Eur Radiol. 2009 Aug;19(8):2033-40
references.pmid: 19280194
references.citation: Magn Reson Med. 2007 Aug;58(2):354-64
references.pmid: 17654578
references.citation: Magn Reson Med. 2008 Nov;60(5):1122-34
references.pmid: 18956464
references.citation: Magn Reson Med. 1986 Dec;3(6):881-900
references.pmid: 3821465
references.citation: AJR Am J Roentgenol. 1991 Feb;156(2):307-12
references.pmid: 1898804
references.citation: Magn Reson Med. 2008 Mar;59(3):521-7
references.pmid: 18306404
references.citation: Radiology. 2008 May;247(2):550-7
references.pmid: 18349314
references.citation: Magn Reson Med. 1997 Apr;37(4):494-500
references.pmid: 9094070
references.citation: Transplantation. 2003 Mar 27;75(6):756-61
references.pmid: 12660497
references.citation: Magn Reson Med. 2008 Mar;59(3):571-80
references.pmid: 18306409
references.citation: Magn Reson Imaging. 1993;11(7):977-91
references.pmid: 8231682
references.citation: J Magn Reson Imaging. 2009 Jul;30(1):145-52
references.pmid: 19557733
references.citation: Radiology. 2009 Apr;251(1):67-76
references.pmid: 19221054
references.citation: J Magn Reson. 1997 Nov;129(1):35-43
references.pmid: 9405214
references.citation: Radiology. 2007 Feb;242(2):450-5
references.pmid: 17255416
references.citation: Eur J Radiol. 2007 Jun;62(3):416-22
references.pmid: 17267159
references.citation: Magn Reson Med. 2002 Mar;47(3):539-48
references.pmid: 11870841
references.citation: Magn Reson Imaging. 2000 Sep;18(7):777-86
references.pmid: 11027870
references.citation: Magn Reson Imaging. 2008 Apr;26(3):347-59
references.pmid: 18093781
references.citation: J Magn Reson. 1998 Mar;131(1):61-8
references.pmid: 9533907