Ultrashort echo time bi‐component analysis of cortical bone—a field dependence study. Issue 3 (29th April 2013)

• Record Type: Journal Article
• Authors: Li, Shihong; Chang, Eric Y.; Bae, Won C.; Chung, Christine B.; Gao, Song; Bao, Shanglian; Bydder, Graeme M.; Hua, Yanqing; Du, Jiang
• Is Part Of: Magnetic resonance in medicine. Volume 71:Issue 3(2014:Mar.)
• Page Start: 1075
• Page End: 1081
• Publication Date: 2013-04-29
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24769
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm24769-sec-0001" sec-type="section"> <title>Purpose</title> <p>The purpose of this study is to investigate the effect of differing field strength on the <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw321z4" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24769:mrm24769-math-0001" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>T</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> of cortical bone at 1.5 T and 3 T.</p> </sec> <sec id="mrm24769-sec-0002" sec-type="section"> <title>Methods</title> <p>Ultrashort echo time pulse sequences were used to study six bovine and nine human bone samples at 1.5 T and 3 T using single‐ and bi‐component <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw321rt" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24769:mrm24769-math-0002" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>T</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> analysis.</p> </sec> <sec id="mrm24769-sec-0003" sec-type="section"> <title>Results</title> <p>On average, the bound water <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw321vg" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24769:mrm24769-math-0003" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>T</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> of bovine bone decreased by 16% (from 0.32 ms at 1.5 T to 0.27 ms at 3 T, <italic>P</italic> < 0.01) and the bound water <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw321mm" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24769:mrm24769-math-0004" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>T</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> of human bone decreased by 21% (from 0.42 ms at 1.5 T to 0.33 ms at 3 T, <italic>P</italic> < 0.01) at the higher field strength. The free water <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw321pq" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24769:mrm24769-math-0005" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>T</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> of bovine bone decreased by 50% (from 4.23 ms at 1.5 T to 2.12 ms at 3 T, <italic>P</italic> < 0.001) and the free water <alternatives><inline-graphic mimetype="image" xlink:href="ark:/27927/pgg4sw321gd" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /><mml:math display="inline" altimg="urn:x-wiley:07403194:media:mrm24769:mrm24769-math-0006" overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>T</mml:mi><mml:mn>2</mml:mn><mml:mo>*</mml:mo></mml:msubsup></mml:mrow></mml:math></alternatives> of human bone decreased by 68% (from 7.65 ms at 1.5 T to 2.46 ms at 3 T, <italic>P</italic> < 0.001) at the higher field strength. Bound and free water fractions showed only minor change with field strength in bovine (< 2%, <italic>P</italic> > 0.05) and human bone (< 4%, <italic>P</italic> > 0.05).</p> </sec> <sec id="mrm24769-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Ultrashort echo time bi‐component analysis provides consistent bound and free water fractions at 1.5 T and 3 T, thereby allowing field‐independent comparisons. <bold>Magn Reson Med 71:1075–1081, 2014. © 2013 Wiley Periodicals, Inc.</bold></p> </sec> </abstract>