In-vivo NMR of hyperpolarized 3He in the human lung at very low magnetic fields

Christopher B. Bidinosti (1) , J. Choukeife (2) , Pierre-Jean Nacher (2) , Geneviève Tastevin (2)

1 SFU - Department of Physics
2 LKB (Lhomond) - Laboratoire Kastler Brossel

We present NMR measurements of the diffusion of hyperpolarized ³He in the human lung performed at fields much lower than those of conventional MRI scanners. The measurements were made on standing subjects using homebuilt apparatus operating at 3mT. O₂-limited transverse relaxation (T₂ up to 15-35 s) could be measured in-vivo. Accurate global diffusion measurements have been performed in-vivo and in a plastic bag; the average apparent diffusion coefficient (ADC) in-vivo was 14.2±0.6 mm²/s, whereas the diffusion coefficient in the bag (³He diluted in N₂) was 79.5±1 mm²/s. 1D ADC mapping with high SNR (~200- 300) demonstrates the real possibility of performing quality lung imaging at extremely low fields.

Mots clés: Hyperpolarised helium; Lung imaging; Diffusion; ADC

Domaines: Physique Médicale [physics.med-ph]; Instrumentations et Détecteurs [physics.ins-det]

Christopher B. Bidinosti, J. Choukeife, Pierre-Jean Nacher, Geneviève Tastevin. In-vivo NMR of hyperpolarized 3He in the human lung at very low magnetic fields. Journal of Magnetic Resonance, 2003, 162, p.122-132. ⟨hal-00001616⟩