Publications [#268936] of G. Allan Johnson

Papers Published
  1. Johnson, GA; Maki, JH, In vivo measurement of proton diffusion in the presence of coherent motion., Investigative Radiology, vol. 26 no. 6 (June, 1991), pp. 540-545 [1650333] .

    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.