Multiple breath washout of hyperpolarized Xe and He in human lungs with three-dimensional balanced steady-state free-precession imaging.

PURPOSE

To compare quantitative fractional ventilation measurements from multiple breath washout imaging (MBW-I) using hyperpolarized He with both spoiled gradient echo (SPGR) and balanced steady-state free precession (bSSFP) three-dimensional (3D) pulse sequences and to evaluate the feasibility of MBW-I with hyperpolarized Xe.

METHODS

Seven healthy subjects were scanned using He MBW-I with 3D SPGR and bSSFP sequences. Five also underwent MBW-I with Xe. A dual-tuned coil was used to acquire MBW-I data from both nuclei in the same subject position, enabling direct comparison of regional information.

RESULTS

High-quality MBW images were obtained with bSSFP sequences using a reduced dose (100 mL) of inhaled hyperpolarized He. 3D MBW-I with Xe was also successfully demonstrated with a bSSFP sequence. Regional quantitative ventilation measures derived from He and Xe MBW-I correlated well in all subjects (P < 0.001) with mean Pearson's correlation coefficients of r = 0.61 and r = 0.52 for He SPGR-bSSFP and Xe- He (bSSFP) comparisons. The average intersubject mean difference (and standard deviation) in fractional ventilation in SPGR-bSSFP and Xe- He comparisons was 15% (28%) and 9% (38%), respectively.

CONCLUSIONS

Improved sensitivity in MBW-I can be achieved with polarization-efficient bSSFP sequences. Same scan-session 3D MBW-I with He and Xe has been demonstrated using a dual-tuned coil. Magn Reson Med 77:2288-2295, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.