Direct imaging of hyperpolarized 129Xe alveolar gas uptake in a mouse model of emphysema. Issue 1 (8th August 2012)

• Record Type: Journal Article
• Authors: Iguchi, Satoshi; Imai, Hirohiko; Hori, Yuki; Nakajima, Junichi; Kimura, Atsuomi; Fujiwara, Hideaki
• Is Part Of: Magnetic resonance in medicine. Volume 70:Issue 1(2013:Jul.)
• Page Start: 207
• Page End: 215
• Publication Date: 2012-08-08
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24452
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>MRI of hyperpolarized <sup>129</sup>Xe dissolved in pulmonary tissues, and blood has the potential to offer a new tool for regional evaluation of pulmonary gas exchange and perfusion; however, the extremely short <italic>T</italic><mml:math overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mtext> </mml:mtext><mml:mrow><mml:mtext>2</mml:mtext></mml:mrow><mml:mrow><mml:mtext>*</mml:mtext></mml:mrow></mml:msubsup></mml:math><inline-graphic xlink:href="ark:/27927/pgg22frch85" mimetype="image" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> and low magnetization density make it difficult to acquire the image. In this study, an ultrashort echo‐time sequence was introduced, and its feasibility to quantitatively assess emphysema‐like pulmonary tissue destruction by a combination of dissolved‐ and gas‐phase <sup>129</sup>Xe lung MRI was investigated. The ultrashort echo‐time has made it possible to acquire dissolved <sup>129</sup>Xe images with reasonably high spatial resolution of 0.625 × 0.625 mm<sup>2</sup> and to obtain <italic>T</italic><mml:math overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mtext> </mml:mtext><mml:mrow><mml:mtext>2</mml:mtext></mml:mrow><mml:mrow><mml:mtext>*</mml:mtext></mml:mrow></mml:msubsup></mml:math><inline-graphic xlink:href="ark:/27927/pgg22frch4z" mimetype="image" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> of 0.67 ± 0.30 ms in a spontaneously breathing mouse at 9.4 T. The regional dynamic alveolar gas uptake as well as subsequent transport by pulmonary blood flow was also visualized. The ratio of <sup>129</sup>Xe magnetization that diffused into the septa relative to the gas‐phase magnetization <italic>F</italic> was regionally evaluated. The mean <italic>F</italic> value of elastase‐treated mice was 2.28 ± 0.46%, which was significantly reduced from that of control mice 3.41 ± 0.48% (<italic>P</italic> = 0.0052). This reflects the reduced uptake efficiency due to alveolar tissue destruction and is correlated with the histologically derived alveolar surface‐to‐volume ratio. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.</p> </abstract>