Use of ethylene glycol to evaluate gradient performance in gradient-intensive diffusion MR sequences

Authors

  • William M. Spees,

    Corresponding author
    1. Department of Radiology, Washington University, St. Louis, Missouri, USA
    • Biomedical MR Laboratory, Department of Radiology, Washington University School of Medicine, 660 South Euclid, St. Louis, MO 63110
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  • Sheng-Kwei Song,

    1. Department of Radiology, Washington University, St. Louis, Missouri, USA
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  • Joel R. Garbow,

    1. Department of Radiology, Washington University, St. Louis, Missouri, USA
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  • Jeffrey J. Neil,

    1. Department of Radiology, Washington University, St. Louis, Missouri, USA
    2. Department of Pediatric Neurology, Washington University, St. Louis, Missouri, USA
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  • Joseph J. H. Ackerman

    1. Department of Radiology, Washington University, St. Louis, Missouri, USA
    2. Department of Chemistry, Washington University, St. Louis, Missouri, USA
    3. Department of Medicine, Washington University, St. Louis, Missouri, USA
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Abstract

Imaging a phantom of known dimensions is a widely used and simple method for calibrating MRI gradient strength. However, full-range characterization of gradient response is not achievable using this approach. Measurement of the apparent diffusion coefficient of a liquid with known diffusivity allows for calibration of gradient amplitudes across a wider dynamic range. An important caveat is that the temperature dependence of the liquid's diffusion characteristics must be known, and the temperature of the calibration phantom must be recorded. In this report, we demonstrate that the diffusion coefficient of ethylene glycol is well described by Arrhenius-type behavior across the typical range of ambient MRI magnet temperatures. Because of ethylene glycol's utility as an NMR chemical-shift thermometer, the same 1H MR spectroscopy measurements that are used for gradient calibration also simultaneously “report” the sample temperature. The high viscosity of ethylene glycol makes it well-suited for assessing gradient performance in demanding diffusion-weighted imaging and spectroscopy sequences. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.

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