Airway imaging in humans using hyperpolarized helium-3 MRI

Most hyperpolarized gas MRI, involving dynamic imaging of the human lungs, requires specialized ultra-fast MRI pulse sequences or the necessity for multiple breaths of hyperpolarized helium. Thus, most current dynamic imaging techniques are not ideal for a clinical setting. By using a standard fast GRE pulse sequence on a GE Signa 1.5 T clinical MRI scanner outfitted with heterodyne functionality, we have developed a clinically feasible method for dynamic human lung imaging of the airways. The technique presented here exploits the non-renewability of hyperpolarized gas to achieve the first distal human airway images with up to 7^th generation resolution of airways. Additionally, this approach requires only a single inspiration of hyperpolarized helium. The airway images achieved may provide unique information about possible causes of pulmonary airway constriction diseases.