Echo time dependence of observed T1 in the human lung. Issue 3 (21st January 2015)

• Record Type: Journal Article
• Authors: Triphan, Simon M.F.; Jobst, Bertram J.; Breuer, Felix A.; Wielpütz, Mark O.; Kauczor, Hans‐Ulrich; Biederer, Jürgen; Jakob, Peter M.
• Is Part Of: Journal of magnetic resonance imaging. Volume 42:Issue 3(2015)
• Page Start: 610
• Page End: 616
• Publication Date: 2015-01-21
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.24840
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jmri24840-sec-0001" sec-type="section"> <title>Background</title> <p>This work is intended to demonstrate that <italic>T<sub>1</sub></italic> measured in the lungs depends on the echo time (<italic>TE</italic>) used. Measuring lung <italic>T<sub>1</sub></italic> can be used to gain quantitative morphological and functional information. It is also shown that this dependence is particularly visible when using an ultra‐short <italic>TE</italic> (UTE) sequence with <italic>TE</italic> well below 1 ms for <italic>T<sub>1</sub></italic> quantification in lung tissue, rather than techniques with <italic>TE</italic> on the order of 1–2 ms.</p> </sec> <sec id="jmri24840-sec-0002" sec-type="section"> <title>Methods</title> <p>The lungs of 12 healthy volunteers (aged 22 to 33 years) were examined at 1.5 Tesla. A segmented inversion recovery Look‐Locker multi‐echo sequence based on two‐dimensional UTE was used for independent <italic>T<sub>1</sub></italic> quantification at five <italic>TE</italic>s between <italic>TE<sub>1</sub></italic> = 70 μs and <italic>TE<sub>5</sub></italic> = 2.3 ms.</p> </sec> <sec id="jmri24840-sec-0003" sec-type="section"> <title>Results</title> <p>The measured <italic>T<sub>1</sub></italic> was found to increase gradually with <italic>TE</italic> from 1060 ± 40 ms at <italic>TE<sub>1</sub></italic> to 1389 ± 53 ms at <italic>TE<sub>5</sub></italic> (<italic>P</italic> < 0.001).</p> </sec> <sec id="jmri24840-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Measuring <italic>T<sub>1</sub></italic> at ultra‐short echo times reveals a significant dependence of observed <italic>T<sub>1</sub></italic> on the echo time. Thus, any comparison of <italic>T<sub>1</sub></italic> values should also consider the <italic>TE</italic>s used. However, this dependence on <italic>TE</italic> could also be exploited to gain additional diagnostic information on the tissue compartments in the lung. J. Magn. Reson. Imaging 2015;42:610–616.</p> </sec> </abstract>