Short‐T2 imaging for quantifying concentration of sodium (23Na) of bi‐exponential T2 relaxation. Issue 1 (30th July 2014)

• Record Type: Journal Article
• Authors: Qian, Yongxian; Panigrahy, Ashok; Laymon, Charles M.; Lee, Vincent K.; Drappatz, Jan; Lieberman, Frank S.; Boada, Fernando E.; Mountz, James M.
• Is Part Of: Magnetic resonance in medicine. Volume 74:Issue 1(2015:Jul.)
• Page Start: 162
• Page End: 174
• Publication Date: 2014-07-30
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.25393
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm25393-sec-0001" sec-type="section"> <title>Purpose</title> <p>This work intends to demonstrate a new method for quantifying concentration of sodium (<sup>23</sup>Na) of bi‐exponential T<sub>2</sub> relaxation in patients on MRI scanners at 3.0 Tesla.</p> </sec> <sec id="mrm25393-sec-0002" sec-type="section"> <title>Theory and Methods</title> <p>Two single‐quantum (SQ) sodium images acquired at very‐short and short echo times (TE = 0.5 and 5.0 ms) are subtracted to produce an image of the short‐T<sub>2</sub> component of the bi‐exponential (or bound) sodium. An integrated calibration on the SQ and short‐T<sub>2</sub> images quantifies both total and bound sodium concentrations. Numerical models were used to evaluate signal response of the proposed method to the short‐T<sub>2</sub> components. MRI scans on agar phantoms and brain tumor patients were performed to assess accuracy and performance of the proposed method, in comparison with a conventional method of triple‐quantum filtering.</p> </sec> <sec id="mrm25393-sec-0003" sec-type="section"> <title>Results</title> <p>A good linear relation (R<sup>2</sup> = 0.98) was attained between the short‐T<sub>2</sub> image intensity and concentration of bound sodium. A reduced total scan time of 22 min was achieved under the SAR restriction for human studies in quantifying both total and bound sodium concentrations.</p> </sec> <sec id="mrm25393-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The proposed method is feasible for quantifying bound sodium concentration in routine clinical settings at 3.0 Tesla. Magn Reson Med 74:162–174, 2015. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>