201. Measurement of T1 of the Ultrashort T2* Components in White Matter of the Brain at 3T
- Author
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Du, Jiang, Sheth, Vipul, He, Qun, Carl, Michael, Chen, Jun, Corey-Bloom, Jody, and Bydder, Graeme M
- Subjects
Engineering ,Physical Sciences ,Biomedical Engineering ,Bioengineering ,Adult ,Animals ,Brain Chemistry ,Cattle ,Humans ,Imaging ,Three-Dimensional ,Magnetic Resonance Imaging ,Male ,Middle Aged ,Myelin Sheath ,Neuroimaging ,Phantoms ,Imaging ,Water ,White Matter ,Whole Body Imaging ,Young Adult ,General Science & Technology - Abstract
Recent research demonstrates that white matter of the brain contains not only long T2 components, but a minority of ultrashort T2* components. Adiabatic inversion recovery prepared dual echo ultrashort echo time (IR-dUTE) sequences can be used to selectively image the ultrashort T2* components in white matter of the brain using a clinical whole body scanner. The T2*s of the ultrashort T2* components can be quantified using mono-exponential decay fitting of the IR-dUTE signal at a series of different TEs. However, accurate T1 measurement of the ultrashort T2* components is technically challenging. Efficient suppression of the signal from the majority of long T2 components is essential for robust T1 measurement. In this paper we describe a novel approach to this problem based on the use of IR-dUTE data acquisitions with different TR and TI combinations to selectively detect the signal recovery of the ultrashort T2* components. Exponential recovery curve fitting provides efficient T1 estimation, with minimized contamination from the majority of long T2 components. A rubber phantom and a piece of bovine cortical bone were used for validation of this approach. Six healthy volunteers were studied. An averaged T2* of 0.32 ± 0.09 ms, and a short mean T1 of 226 ± 46 ms were demonstrated for the healthy volunteers at 3T.
- Published
- 2014