129Xe is hyperpolarised on site to >50% polarisation using a Rubidium spin exchange polariser, and administered through a Tedlar bag. The 129Xe polarisation process has regulatory approval as an IMP for lung imaging from the MHRA (UK-MAIMP-29724). 129Xe will be manufactured as required for study volunteers. Manufactured 129Xe is held in a bag prior to administration to the study participant. Bags of manufactured gas will be labelled using labels approved by the MHRA. Drug accountability records will be held in the site file to document the administration of 129Xe to study participants. Hyperpolarised 129Xe will be prescribed to the participants prior to administration by a medically qualified study investigator using the study-specific prescription.