¹⁹F MRI of human lungs at 0.5 Tesla using octafluorocyclobutane

Abstract

Purpose The aim of this study was to demonstrate the feasibility of fluorine‐19 (19F) MRI of the human lungs using octafluorocyclobutane (OFCB, C4F8). This gas has 8 magnetically equivalent fluorine nuclei and relatively long T1 and T2 (˜50 ms), which render it suitable as an MRI contrast agent. Previous experiments in small laboratory animals showed that OFCB could be successfully used as an alternative to the gases often used for 19F MRI (sulfur hexafluoride and perfluoropropane). Methods One male volunteer participated in this study. Immediately before an MRI scan, the volunteer inhaled the gas mixture—80% OFCB with 20% oxygen—and held his breath. Experiments were performed on a 0.5T whole‐body MR scanner with a customized transmit–receive coil tuned at 19F frequency. Fast spin echo in 2D and 3D modes was used for image acquisition. 2D images were obtained with in‐plane resolution of 10 × 10 mm2 without slice selection. 3D images were obtained with the voxel size of 10 × 10 × 30 mm2. Breath‐hold duration was 20 s for 2D and 40 s for 3D imaging, respectively. Results Anatomically consistent 19F MR images of the human lungs were obtained with SNR around 50 in 2D mode and 20 in 3D mode. 3D volumetric images of the lungs were reconstructed and provided physiologically reasonable volume estimates. Conclusion The application of OFCB enables informative 19F lung imaging even at low magnetic field strengths. The OFCB gas shows promise as an inhalable contrast agent for fluorine lung MRI and has a potential for clinical translation.

Multinuclear MRI Research

“…Figure 6 shows 19 F MRI images of the rat lungs obtained on a 7-T scanner [ 12 , 14 ], and Fig. 7 images of the lungs of a volunteer obtained with a 0.5-T scanner [ 17 ].

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“…The color scale corresponds to the SNR values in 19 F MRI images. The images were obtained on the medical 0.5-T scanner [ 17 ] …”

Evaluation of fluorine‐19 magnetic resonance imaging of the lungs using octafluorocyclobutane in a rat model

“…Recently, the first spin-echo images of human lungs using OFCB were acquired at 0.5T. 20 The goal of this work was to compare OFCB with PFP and to determine the feasibility of using OFCB as a fluorinated gas for 19 F lung MRI by comparing its SNR to the SNR of PFP scans. In this work, we demonstrate that OFCB has a higher SNR than PFP for both MR spectroscopy and imaging.…”

“…Previous reports by Wolf et al 18 and Friedrich et al 19 used OFCB for the visualization of inert gas washout during high‐frequency oscillatory ventilation. Recently, the first spin‐echo images of human lungs using OFCB were acquired at 0.5T 20 …”

MR properties of 19F C3F8 gas in the lungs of healthy volunteers: and apparent diffusion coefficient at 1.5T and at 3T

“…Currently, lung imaging with fluorinated gases (SF 6 , C 2 F 6 , C 3 F 8 , C 4 F 8 1 ) MRI is not as well‐characterized as hyperpolarized (HP) gas MRI, with a relative paucity in the literature. For example, there have already been numerous longitudinal and clinical studies performed with 3 He and 129 Xe gases 2‐4 .…”