Publications [#269070] of G. Allan Johnson

Papers Published

1. Chen, XJ; Möller, HE; Chawla, MS; Cofer, GP; Driehuys, B; Hedlund, LW; MacFall, JR; Johnson, GA, Spatially resolved measurements of hyperpolarized gas properties in the lung in vivo. Part II: T *(2)., Magn Reson Med, vol. 42 no. 4 (October, 1999), pp. 729-737, ISSN 0740-3194 [10502762], [doi]
   (last updated on 2024/04/19)

   Abstract:
   The transverse relaxation time, T *(2), of hyperpolarized (HP) gas in the lung in vivo is an important parameter for pulse sequence optimization and image contrast. We obtained T *(2) maps of HP (3)He and (129)Xe in guinea pig lungs (n = 17) and in human lungs. Eight different sets of (3)He guinea pig studies were acquired, with variation of slice selection, tidal volume, and oxygen level. For example, for a (3)He tidal volume of 3 cm(3) and no slice selection, the average T *(2) in the trachea was 14.7 ms and 8.0 ms in the intrapulmonary airspaces. The equivalent (129)Xe experiment yielded an average T *(2) of 40.8 ms in the trachea and 18.5 ms in the intrapulmonary airspaces. The average (3)He T *(2) in the human intrapulmonary airspaces was 9.4 ms. The relaxation behavior was predicted by treating the lung as a porous medium, resulting in good agreement between estimated and measured T *(2) values in the intrapulmonary airspaces. Magn Reson Med 42:729-737, 1999.

   Keywords:
   Animals • Guinea Pigs • Helium • Humans • Isotopes • Lung • Magnetic Resonance Imaging • Male • Middle Aged • Pulmonary Diffusing Capacity • Trachea • Xenon Isotopes • anatomy & histology • anatomy & histology* • diagnostic use • methods*