Triple-quantum filtered NMR imaging of sodium in the human brain [electronic resource]
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| Online Access: |
Online Access (via OSTI) |
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| Corporate Author: | |
| Format: | Government Document Thesis Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Department of Energy. ; distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
1993.
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| Subjects: |
| Abstract: | In the past multiple-quantum filtered imaging of biexponential relaxation sodium-23 nuclei in the human brain has been limited by low signal to noise ratios; this thesis demonstrates that such imaging is feasible when using a modified gradient-selected triple-quantum filter at a repetition time which maximizes the signal to noise ratio. Nuclear magnetic resonance imaging of biexponential relaxation sodium-23 (<sup>23</sup>Na) nuclei in the human brain may be useful for detecting ischemia, cancer, and pathophysiology related to manic-depression. Conventional single-quantum NMR imaging of in vivo biexponential relaxation <sup>23</sup>Na signals is complicated by the presence of single-exponential relaxation <sup>23</sup>Na signals. Multiple-quantum filters may be used to selectively image biexponential relaxation <sup>23</sup>Na signals since these filters suppress single-exponential relaxation <sup>23</sup>Na signals. In this thesis, the typical repetition times (200--300 ms) used for in vivo multiple-quantum filtered <sup>23</sup>Na experiments are shown to be approximately 5 times greater than the optimal repetition time which maximizes multiple-quantum filtered SNR. Calculations and experimental verification show that the gradient-selected triple-quantum (GS3Q) filtered SNR for <sup>23</sup>Na in a 4% agarose gel increases by a factor of two as the repetition time decreases from 300 ms to 55 ms. The measured relaxation times of the <sup>23</sup>Na in the 4% agarose gel were similar to in vivo <sup>23</sup>Na relaxation times. |
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| Item Description: | Published through SciTech Connect. 04/01/1993. "lbl--34375" "DE93040607" ": Grant HL 25840" "Grant HL 07367" "Grant 89-20133" John Robinson Keltner. |
| Physical Description: | 95 p. : digital, PDF file. |
| Dissertation Note: | Thesis (Ph.D.); PBD: Apr 1993. |