Study on magnetic resonance imaging of gaseous medium (1st report, imaging of pressurized gas and influence of molecular diffusion on imaging)

In this article, application of magnetic resonance (MR) imaging to pressurized gas is described. A specially-designed non-magnetic test vessel offers cylindrical sample chamber with 12 mm i.d. and 114 mm in length, in which methane gas was supplied up to 10.0 MPa in order to investigate its feasibility of gas MR imaging. Experiments with glass beads were also conducted and it is shown that MR imaging technique successfully produces methane images with glass beads owing to high proton density at pressurized fields. Furthermore, hydrogen gas was used instead of methane in an effort to examine influence of gaseous properties on gas MR imaging. It is shown that signal intensity on MR images of hydrogen was much less than that of methane due to high diffusivity of hydrogen molecules, which was also confirmed by numerical calculation.