title: Use of ethylene glycol to evaluate gradient performance in gradient-intensive diffusion MR sequences.
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 (1)H 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.
authors: Department of Radiology, Washington University, St Louis, Missouri 63110, USA. spees@wustl.edu
authors: William M
authors: WM
authors: Spees
authors: Sheng-Kwei
authors: SK
authors: Song
authors: Joel R
authors: JR
authors: Garbow
authors: Jeffrey J
authors: JJ
authors: Neil
authors: Joseph J H
authors: JJ
authors: Ackerman
mesh_terms: D040761:Biomimetic Materials / Q000032:analysis* / Q000737:chemistry*; D038524:Diffusion Magnetic Resonance Imaging / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019855:Ethylene Glycol / Q000032:analysis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D008422:Materials Testing; D019047:Phantoms, Imaging
chemical_list: D019855:Ethylene Glycol