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Can I read T1ρ MRI contrast in the human brain: Modulation of the longitudinal rotating frame relaxation shutter-speed during an adiabatic RF pulse on EtoBox?
T1ρ MRI contrast in the human brain: Modulation of the longitudinal rotating frame relaxation shutter-speed during an adiabatic RF pulse by Shalom Michaeli; Dennis J. Sorce; Charles S. Springer Jr.; Kamil Ugurbil; Michael Garwood is a Chemistry article available to read on EtoBox.
What is T1ρ MRI contrast in the human brain: Modulation of the longitudinal rotating frame relaxation shutter-speed during an adiabatic RF pulse about?
Longitudinal relaxation in the rotating frame (T1rho) is the dominant mechanism during a train of adiabatic full passage (AFP) RF pulses with no interpulse intervals, placed prior to an excitation pulse. Asymptotic apparent time constants (T1rho') were measured for human occipital lobe 1H2O at 4T using brief imaging readouts following such pulse trains. Two members of the hyperbolic secant (HSn) AFP pulse family (n=1 or 4; i.e., arising from different amplitude- and frequency-modulation functions) were used. These produced two different non-monoexponential signal decays during the pulse trains. Thus, there are differing contrasts in asymptotic T1rho' maps derived from these data. This behavior is quite different than that of 1H2O signals from an aqueous protein solution of roughly the same macromolecular volume fraction as tissue. The ROI-averaged decays from the two acquisitions can be simultaneously accommodated by a two-site-exchange model for an equilibrium isochronous process whose exchange condition is modulated during the pulse. The model employs a two-spin description of dipolar interaction fluctuations in each site. The intrinsic site R1rho(identical with T1rho(-1)) value
Who reads T1ρ MRI contrast in the human brain: Modulation of the longitudinal rotating frame relaxation shutter-speed during an adiabatic RF pulse?
It is typically read by researchers, students, and practitioners in Chemistry.
- Author
- Shalom Michaeli; Dennis J. Sorce; Charles S. Springer Jr.; Kamil Ugurbil; Michael Garwood
- Publisher
- Elsevier Science; Elsevier ; Elsevier Inc.; Elsevier BV (ISSN 1090-7807)
- Published
- 2006
- Language
- EN
- Field
- Chemistry (Physical Sciences)