Publications [#269110] of G. Allan Johnson

Papers Published

1. Middleton, H; Black, RD; Saam, B; Cates, GD; Cofer, GP; Guenther, R; Happer, W; Hedlund, LW; Johnson, GA; Juvan, K, MR imaging with hyperpolarized 3He gas., Magn Reson Med, vol. 33 no. 2 (February, 1995), pp. 271-275, ISSN 0740-3194 [7707920], [doi]
   (last updated on 2025/07/03)

   Abstract:
   Magnetic resonance images of the lungs of a guinea pig have been produced using hyperpolarized helium as the source of the MR signal. The resulting images are not yet sufficiently optimized to reveal fine structural detail within the lung, but the spectacular signal from this normally signal-deficient organ system offers great promise for eventual in vivo imaging experiments. Fast 2D and 3D GRASS sequences with very small flip angles were employed to conserve the norenewable longitudinal magnetization. We discuss various unique features associated with performing MRI with hyperpolarized gases, such as the selection of the noble gas species, polarization technique, and constraints on the MR pulse sequence.

   Keywords:
   Animals • Guinea Pigs • Helium • Image Enhancement • Lasers • Lung • Magnetic Resonance Imaging* • Magnetic Resonance Spectroscopy • Rubidium • Time Factors • anatomy & histology* • chemistry • diagnostic use* • metabolism • methods • radiation effects