In vivo diffusion weighted ¹⁹F MRI using SF₆

Abstract

Diffusion weighted 19 F images of rat lung in vivo using SF 6 are presented. Projection-reconstruction images were acquired by filling the rat lung with a mixture of SF 6 and air, during 64 successive apneas. Each apnea lasted for 6 s, the time required to perform 100 accumulations of each k-space radial phase step for the five values of the diffusion gradient (TR ‫؍‬ 10 ms). After diffusion images were acquired, an apparent diffusion coefficient (ADC) map was generated, yielding an average value for the ADC of 2.22 ؋ 10 -6 m 2 /s and SD for ADC values of 1.27 ؋ 10 -6 m 2 /s. To the best of our knowledge, this is the first in vivo diffusion weighting imaging application and the first ADC map obtained using 19

Proton MRI as a noninvasive tool to assess elastase‐induced lung damage in spontaneously breathing rats

“…However, they require specialized, costly equipment and are subject to patent issues. Measurements of the diffusion of the SF 6 gas in the lungs with 19 F MRI may be an interesting alternative (38); however, application of the technique to an elastase model has not yet been demonstrated.…”

Visualization of inert gas wash‐out during high‐frequency oscillatory ventilation using fluorine‐19 MRI

“…Likewise, but with much less technical effort, ventilation can be visualized using fluorinated gases. This has been demonstrated mainly for SF 6 and C 2 F 6 (11–19). Because of the natural Boltzmann polarization state of these gases, the image quality imposes limits to temporal resolution.…”

Perfluoropropane Gas as a Magnetic Resonance Lung Imaging Contrast Agent in Humans

“…Advances in the fi eld led to a number of studies in animal models (eg, swine, canine, rodents) [36][37][38][39] and excised human lungs, 40,41 demonstrating the suitabil ity of 19 F-enhanced MRI in regional assessments of pulmonary function. The renewable signal characteristics of PFP provide the means for assessing ventilationdefect severity, volume, and gas-trapping severity in patients with COPD and those with asthma, thus, providing a regional insight into the degree of underlying disease heterogeneity.…”