Ventilation study of the human lungs by 19F MRI at 0.5 Tesla

Abstract Purpose: To obtain information on functional lung activity by 19F MRI using low field (0.5T) MRI scanner.Methods: Two healthy and one post-Covid volunteers participated in the studies. As a contrast for 19F pulmonary MRI, the octafluorcyclobutane gas (OFCB) mixed with oxygen was used. MR scans of human lungs were conducted by 2D and 3D FSE methods. MRI data were used for volume reconstruction, calculation of V/Q, wash-in/-out and single breath dynamic measurements.Results: 3D imaging revealed gas distribution inhomogeneity in the post-Covid lungs. V/Q maps showed that the mean value of V/Q in the post-Covid lungs was less than in the healthy lungs - 0.1 vs. 0.5. The wash-in/-out dynamic measurements determined that fractional ventilation is 12±2% and wash-in time is 90±20s. Dynamics of gas distribution during one breath cycle was analyzed. The calculated inspiration and expiration maps gave normalized effective times for these stages - 0.30±0.07 and 0.15±0.04, respectively. Conclusion: Different 19F pulmonary MRI methods were implemented: 3D imaging, V/Q-mapping, wash-in/-out dynamics and single respiratory cycle imaging. The results are agreed with known data and demonstrates possibility of ventilation assessment of the lungs at 0.5 Tesla.