publications by G. Allan Johnson.
search www.ncbi.nlm.nih.gov.
Papers Published
- 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*