Martin H. Deppe1, Salma Ajraoui1,
Helen Marshall1, Jim M. Wild1
1Academic Radiology,
This
work investigates the influence of O2 on the T2*
of hyperpolarized 3He in human lungs. To separate the effect of O2
from the known lung inflation dependence, T2* maps were
obtained at expiration and full inspiration, both at baseline breathing air
and after 4 min of pure O2. It is found that the effect of lung
inflation dominates over any potential O2 effect, which is
proposed to be due to a combination of motional narrowing and the fact that 3He
is distributed over the whole alveolus, while 1H spins are
confined to the interfaces, where susceptibility gradients are strongest.