title: Assessment of relative brain iron concentrations using T2-weighted and T2*-weighted MRI at 3 Tesla.
abstract: In this paper a new method is presented for the relative assessment of brain iron concentrations based on the evaluation of T2 and T2*-weighted images. A multiecho sequence is employed for rapid measurement of T2 and T2*, enabling calculation of the line broadening effect (T2'). Several groups have failed to show a correlation between T2 and brain iron content. However, quantification of T2', and the associated relaxation rate R2', may provide a more specific relative measure of brain iron concentration. This may find application in the study of brain diseases, which cause associated changes in brain iron levels. A new method of field inhomogeneity correction is presented that allows the separation of global and local field inhomogeneities, leading to more accurate T2* measurements and hence, T2' values. The combination of T2*, and T2-weighted MRI methods enables the differentiation of Parkinson's disease patients from normal age-matched controls based on differences in iron content within the substantia nigra.
authors.affiliation: Department of Neurology, Henry Ford Hospital & Health Sciences Center, Detroit, Michigan.
authors.forename: R J
authors.initials: RJ
authors.lastname: Ordidge
authors.forename: J M
authors.initials: JM
authors.lastname: Gorell
authors.forename: J C
authors.initials: JC
authors.lastname: Deniau
authors.forename: R A
authors.initials: RA
authors.lastname: Knight
authors.forename: J A
authors.initials: JA
authors.lastname: Helpern
mesh_terms: D000368:Aged; D000465:Algorithms; D001923:Brain Chemistry; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007501:Iron / Q000032:analysis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000378:metabolism; D013378:Substantia Nigra / Q000737:chemistry
chemical_list: D007501:Iron