Abstract
Introduction: The nitrogen multiple breath washout (N2MBW) technique measures global ventilation inhomogeneity (VI) through breathing 100% oxygen (O2) to washout resident nitrogen. Dynamic oxygen-enhanced (dOE) MRI assesses regional VI by measuring changes in pulmonary relaxation time (T1) upon exposure to O2.
Aim: To assess feasibility and compare outcomes from simultaneous N2MBW and dOE MRI measurements.
Methods: We performed simultaneous N2MBW and dOE MRI in a healthy volunteer with 4s breath-holding (BH) allowing for higher MRI quality than in free-breathing. We assessed and compared N2 and O2 concentrations for each washout breath from MBW and dOE MRI. We obtained gas concentrations from dOE MRI by fitting exponential T1 signal decay and setting the initial/final concentrations to 79%N2 (21% O2)/ 0%N2 (100% 02).
Results: Simultaneous MBW and dOE MRI testing was feasible but technically challenging. Quantitative and functional image quality (Figure 1A) was comparable with previous studies. The N2 and O2 concentration curves from dOE MRI were similar to those from MBW (Figure 1A-B). The end-of-test criteria for MBW at 2.5% N2 was reached after 7 washout breaths for both MBW and MRI.
Measurements and Main Results: Simultaneous assessment of MBW and dOE MRI may allow for more comprehensive assessment of lung ventilation. Further studies are needed to enhance MBW MRI compatibility.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA3216.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2021
