A quantitative study of water proton relaxation in packed beds of porous particles with varying water content

Hills, B.P.; Babonneau, Florence

doi:10.1016/0730-725x(94)92032-x

Cited by 21 publications

(11 citation statements)

References 16 publications

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“…This gives the ability to choose a region in the sample for recording the NMR signal. NMR has been used to obtain the moisture profiles in numerous food materials during drying (Duce & Hall, 1995;Hills & Babonneau, 1994b;Ishida, Ogawa, Koizumi, & Kano, 1997;Song & Litchfield, 1994;Tomer, Mantle, Gladden, & Newton, 1999). Verstreken, Hecke, and Scheerlinck (1998) and Schrader and Litchfield (1992) compared moisture profiles obtained using NMR to the profiles obtained using finite difference solution of a Fickian diffusion equation in a cylindrical food gel.…”

Section: Introductionmentioning

confidence: 99%

NMR imaging of continuous and intermittent drying of pasta

Xing

Takhar

Helms

et al. 2007

Journal of Food Engineering

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Section: Introductionmentioning

confidence: 99%

NMR imaging of continuous and intermittent drying of pasta

Xing

Takhar

Helms

et al. 2007

Journal of Food Engineering

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“…The contributions to relaxation from chemical exchange at high fields can be partially reduced in the presence of stronger locking fields, so that the value of T 1ρ depends on the choice of experimental parameters. The variation of R 1ρ with spin-locking field strength, known as R 1ρ dispersion, can then provide quantitative information relevant to chemical and diffusive exchange [8,10,11,13], and therefore can in principle provide a more complete characterization of tissue composition and alterations associated with pathology. In spite of this, only very few R 1ρ (or T 1ρ ) dispersion studies in biological tissues have been reported previously, and mostly these have been at lower magnetic field strengths [14,15] where exchange effects are much less important.…”

Section: Introductionmentioning

confidence: 99%

Chemical exchange in knee cartilage assessed by R1ρ (1/T1ρ) dispersion at 3T

Wang

Block

Gore

2015

Magnetic Resonance Imaging

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Purpose To quantify the characteristics of proton chemical exchange in knee cartilage in vivo by R1ρ dispersion analysis. Materials and Methods Six healthy subjects (one female and five males, age range 24 to 71 y) underwent T1ρ imaging of knee cartilage on a 3T MRI scanner. Quantitative estimates of R1ρ (=1/T1ρ) were made using 5 different spin-lock durations for each of 12 different spin-lock amplitudes over the range 0 to 550 Hz. When the variations of R1ρ with spin-locking strength (the R1ρ dispersion) are dominated by chemical exchange contributions, R1ρ dispersion curves can be analyzed to derive quantitative characteristics of the exchange and provide information on tissue composition. In this work, in vivo R1ρ dispersion of human knee articular cartilage at 3T was analyzed, and the exchange rates of protons between water and macromolecular hydroxyls (mainly in glycosaminoglycans) were estimated based on a theoretical model. Results R1ρ values showed marked dispersion in articular cartilage and varied by approximately 50% between low and high values of the locking field, a change much greater than in surrounding tissues, consistent with greater contributions from chemical exchange. From the theoretical model, the exchange rates in cartilage were estimated to be in the range of 1.0 – 3.0 kHz, and varied within the tissue. Variations within a single knee appear to be larger with increasing age. Conclusion R1ρ dispersion analysis may provide more specific information for studying cartilage biochemical composition and form the basis for quantitative evaluation of cartilage disorders.

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“…Figure 11 shows the results for randomly packed beds of Sephadex G25-300 and G25-50. The large Sephadex G25-300 microspheres swell to c 300 pm diameter in excess water so that the water proton transverse relaxation is multiple exponential and in the intermediate diffusive exchange regime (Hills and Babonneau 1994). Figure 12 shows the dependence of the water proton transverse relaxation time distributions on water content in the Sephadex G25-300 beds.…”

Section: Nmr Relaxation and Archies Law Of Electrical Conductionmentioning

confidence: 98%