1H NMR measurements of wet/dry ratio and T1, T2 distributions in lung.
Proton-magnetic-resonance measurements have been carried out on juvenile porcine peripheral lung parenchyma. The free-induction-decay signal contained a motionally restricted component which decayed in a few tens of microseconds and a mobile component with a T2 time greater than 1 ms. The average second moment, M2, for the motionally restricted signal was found to be 3.42 +/- (0.25) x 10(9) s-2. The T2 distribution for the mobile signal consistently showed four resolvable components of T2 range: 2-6, 10-40, 80-110, and 190-400 ms. The 2-6 ms component was present in a fully dehydrated preparation and was therefore assigned to a nonaqueous lung constituent. The motionally restricted FID component had a T1 = 0.772 +/- 0.11 s and the mobile component had a T1 = 0.967 +/- 0.02 s. The hydrogen content per unit mass for lung parenchyma and water were estimated in two ways: (1) on the basis of chemical content and (2) on the basis of comparison of restricted and mobile signals to the gravimetric (G) water content for a lung sample studied at a wide range of water contents. Lung wet/dry weight ratios were estimated from the free-induction decays and compared with gravimetric measurement. The ratio of (wet/dry)NMR/(wet/dry)G was 1.00 +/- 0.08 and 1.00 +/- 0.05 for the two methods of estimation.
Estilaei
M
M
Department of Physics, University of British Columbia, Vancouver, Canada.
MacKay
A
A
Roberts
C
C
Mayo
J
J
D000818:Animals; D003094:Collagen / Q000032:analysis; D015633:Extravascular Lung Water / Q000737:chemistry*; D008168:Lung / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D009929:Organ Size; D013552:Swine
D003094:Collagen