Volume‐Controlled ¹⁹F MR Ventilation Imaging of Fluorinated Gas

Abstract

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.

Examining lung microstructure using 19F MR diffusion imaging in COPD patients

“…For 19 F imaging, each study participant inhaled a mixture of 79% C 3 F 8 and 21% oxygen through a disposable mouthpiece with a nose clip from a 30‐l reservoir bag. Participants were guided by acoustic breathing commands, while real‐time measurement and control of the gas flow using pneumotachometers and pneumatic valves ensured a fixation of the inhaled gas volume to 1/8 inspiratory vital capacity (VC in ) for each breath hold 35 . After a proton image was acquired in breath hold using a 3D volume interpolated spoiled gradient‐echo sequence, the gas delivery was switched from room air to the C 3 F 8 /O 2 mixture, and the participants took eight consecutive breaths, each one followed by a 19 F scan in breath hold (6 s each).…”

“…After a proton image was acquired in breath hold using a 3D volume interpolated spoiled gradient‐echo sequence, the gas delivery was switched from room air to the C 3 F 8 /O 2 mixture, and the participants took eight consecutive breaths, each one followed by a 19 F scan in breath hold (6 s each). During these eight breath holds, conventional gas ventilation imaging is performed, enabling the computation of ventilation defects and gas wash‐in kinetics, which is beyond the scope of this paper 35 . After the ninth breath, ventilation of most of the lung is assumed; hence, four images were acquired for S/V mapping in a single breath hold (14 s).…”

Initial feasibility and challenges of hyperpolarized 129Xe MRI in neonates with bronchopulmonary dysplasia

“…Although this can be largely removed by cropping the images and using the 1 H anatomical images as a guide, in future acquisitions, we aim to optimize the gas delivery procedure-for example using a free-breathing/multiple-breath approach with HP 129 Xe and O 2 gas mixtures. Such a system would need to take inspiration from automated gas-delivery systems demonstrated in both adult and small animal imaging MRI fields, as infant lung volumes lie in between these two extremes, [47][48][49][50] and are not dissimilar from typical dead-space volumes in gas-delivery equipment. Furthermore, we will consider using an RF coil with a smaller/more lung-localized sensitive volume.…”