Feasibility of human lung ventilation imaging using highly polarized naturally abundant xenon and optimized three‐dimensional steady‐state free precession. Issue 2 (27th April 2015)

• Record Type: Journal Article
• Authors: Stewart, Neil J.; Norquay, Graham; Griffiths, Paul D.; Wild, Jim M.
• Is Part Of: Magnetic resonance in medicine. Volume 74:Issue 2(2015:Aug.)
• Page Start: 346
• Page End: 352
• Publication Date: 2015-04-27
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.25732
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm25732-sec-0001" sec-type="section"> <title>Purpose</title> <p>To demonstrate the potential for high quality MRI of pulmonary ventilation using naturally abundant xenon (NAXe) gas.</p> </sec> <sec id="mrm25732-sec-0002" sec-type="section"> <title>Methods</title> <p>MRI was performed at 1.5 Tesla (T) and 3 T on one healthy smoker and two healthy never‐smokers. <sup>129</sup>Xe gas was polarized to ∼25% using an in‐house spin‐exchange optical pumping polarizer fitted with a laser diode array with integrated volume holographic grating and optical train system. Volunteers inhaled 1 L of NAXe for an 8 to 15 s breathhold while MR images were acquired with full‐lung coverage using a three‐dimensional steady‐state free precession sequence, optimized for maximum signal‐to‐noise ratio (SNR) at a given spatial resolution. For the purpose of image quality comparison, the MR acquisition was repeated at 1.5 T with 400 mL enriched xenon and 200 mL <sup>3</sup>He.</p> </sec> <sec id="mrm25732-sec-0003" sec-type="section"> <title>Results</title> <p>All NAXe lung images were of high quality, with mean SNRs of 25–40 (voxel 4.2 × 4.2 × 8/10 mm<sup>3</sup>) and ∼30% improvement at 3 T versus 1.5 T. The high SNR permitted identification of minor ventilation defects in the healthy smoker's lungs. NAXe images were of comparable SNR to those obtained with enriched xenon and <sup>3</sup>He.</p> </sec> <sec id="mrm25732-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Optimization of MR pulse sequences and advances in polarization technology have facilitated high quality pulmonary ventilation imaging with inexpensive NAXe gas. Magn Reson Med 74:346–352, 2015. © 2015 Wiley Periodicals, Inc.</p> </sec> </abstract>