Quantitative MR Imaging of 3He Gas Transport in Model Airways
Minard K, Jacob R
Pacific Northwest National Laboratory
The feasibility of quantifying gas transport in the major airways of adult rats is examined by employing two-dimensional (2D) constant-time imaging (CTI) for measuring the dynamics of hyperpolarized (HP) 3He in a straight pipe with a diameter comparable to the rat trachea. At physiological flow rates, measured maps of axial flow and diffusion are shown to be accurately predicted using a simple transport model that describes 3Hes diffusion across flow lamina. Since the diffusion-mediated model is generally applicable to any flow conduit, results provide a quantitative basis for studying gas transport with noninvasive 3He MRI.