title: T2 prep three-dimensional spiral imaging with efficient whole brain coverage for myelin water quantification at 1.5 tesla.
abstract: Quantitative assessment of myelination is important for characterizing tissue damage and evaluating response to therapy in white matter diseases such as multiple sclerosis. Conventional multicomponent T(2) relaxometry based on the two-dimensional (2D) multiecho spin echo sequence is a promising method to measure myelin water fraction, but its clinical utility is impeded by the prohibitively long data acquisition and limited brain coverage. The objective of this study was to develop a signal-to-noise ratio efficient 3D T(2) prep spiral gradient echo (3D SPIRAL) sequence for full brain T(2) relaxometry and to validate this sequence using 3D multiecho spin echo as reference standard in healthy brains at 1.5 T. 3D SPIRAL was found to provide similar myelin water fraction in six selected white and gray matter areas using region-of-interest signal averaging analysis (N = 7, P > 0.05). While 3D multiecho spin echo only provided partial brain coverage, 3D SPIRAL enabled whole brain coverage with a fivefold higher acquisition speed per imaging slice and similar signal-to-noise ratio efficiency. Both 3D sequences provided superior signal-to-noise ratio efficiency when compared to the conventional 2D multiecho spin echo approach.
authors.affiliation: Department of Radiology, Weill Cornell Medical College, New York, New York, USA. tdn2001@med.cornell.edu
authors.forename: Thanh D
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Cynthia
authors.initials: C
authors.lastname: Wisnieff
authors.forename: Mitchell A
authors.initials: MA
authors.lastname: Cooper
authors.forename: Dushyant
authors.initials: D
authors.lastname: Kumar
authors.forename: Ashish
authors.initials: A
authors.lastname: Raj
authors.forename: Pascal
authors.initials: P
authors.lastname: Spincemaille
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Tim
authors.initials: T
authors.lastname: Vartanian
authors.forename: Susan A
authors.initials: SA
authors.lastname: Gauthier
mesh_terms: D000328:Adult; D001834:Body Water / Q000737:chemistry*; D001931:Brain Mapping / Q000379:methods*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009186:Myelin Sheath / Q000737:chemistry*; D019047:Phantoms, Imaging