title: Local diffusion and diffusion-T2distribution measurements in porous media.
abstract: Slice-selective pulsed field gradient (PFG) and PFG-T2measurements are developed to measure spatially-resolved molecular diffusion and diffusion-T2distributions. A spatially selective adiabatic inversion pulse was employed for slice-selection. The slice-selective pulse is able to select a coarse slice, on the order of 1cm, at an arbitrary position in the sample. The new method can be employed to characterize oil-water mixtures in porous media. The new technique has an inherent sensitivity advantage over phase encoding imaging based methods due to signal being localized from a thick slice. The method will be advantageous for magnetic resonance of porous media at low field where sensitivity is problematic. Experimental CPMG data, following PFG diffusion measurement, were compromised by a transient ΔB0(t) field offset. The off resonance effects of ΔB0(t) were examined by simulation. The ΔB0offset artifact in D-T2distribution measurements may be avoided by employing real data, instead of magnitude data.
authors.affiliation: UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada. Electronic address: Sarah.Vashaee@unb.ca.
authors.forename: S
authors.initials: S
authors.lastname: Vashaee
authors.affiliation: UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada. Electronic address: bnewling@unb.ca.
authors.forename: B
authors.initials: B
authors.lastname: Newling
authors.affiliation: UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada. Electronic address: bryce@unb.ca.
authors.forename: B
authors.initials: B
authors.lastname: MacMillan
authors.affiliation: UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada. Electronic address: fmarica@unb.ca.
authors.forename: F
authors.initials: F
authors.lastname: Marica
authors.affiliation: UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada. Electronic address: Ming.Li@unb.ca.
authors.forename: M
authors.initials: M
authors.lastname: Li
authors.affiliation: UNB MRI Centre, Department of Physics, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada. Electronic address: bjb@unb.ca.
authors.forename: B J
authors.initials: BJ
authors.lastname: Balcom
keywords: Adiabatic inversion; CPMG; D-T(2); Diffusion; Inverse Laplace transform NMR; Magnetic resonance; Porous media; Relaxation times; Slice-selection; Spin echo; ΔB(0)(t)