publications by G. Allan Johnson.


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Papers Published

  1. GA Johnson, JH Maki, In vivo measurement of proton diffusion in the presence of coherent motion., Investigative radiology, UNITED STATES, vol. 26 no. 6 (June, 1991), pp. 540-5 .
    (last updated on 2005/08/03)

    Abstract:
    Measurement of the self-diffusion coefficient D of water in tissue has been performed traditionally using the technique proposed by Stejskal and Tanner. A variant of that technique is shown here, employing flow-compensated gradients that significantly reduce the sensitivity to small coherent motions that are common in body imaging. An interleaved sequence with four values of diffusion-sensitizing gradient (b) minimizes registration errors. Eddy currents and other systematic errors are reduced, permitting the measurement of standards in an imaging context within 5% of nonimaging values in the literature. The flow-compensated sequence permits the measure of D for tissues in the abdominal cavity of the rat. We present in vivo measurements of D for the following rat tissues; liver, kidney (cortex), kidney (medulla) muscle, brain, fat.

    Keywords:
    Acetone • Animals • Diffusion • Dimethyl Sulfoxide • Magnetic Resonance Imaging • Movement • Protons* • Rats • Water • methods*