A standardised method for measuring magnetisation transfer ratio on MR imagers from different manufacturers--the EuroMT sequence

Barker, G. J., Schreiber, W. G., Gass, A., Ranjeva, J. P., Campi, A., van Waesberghe, J. H., Franconi, J. M., Watt, H. C. and Tofts, P. S. (2005) A standardised method for measuring magnetisation transfer ratio on MR imagers from different manufacturers--the EuroMT sequence. Magnetic Resonance Materials in Physics, Biology and Medicine, 18 (2). pp. 76-80. ISSN 0968-5243

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Abstract

Magnetisation transfer ratio (MTR) is increasingly used to evaluate neurological disorders, especially those involving demyelination. It shows promise as a surrogate marker of disease progression in treatment trials in multiple sclerosis (MS) but the value measured is highly dependent on pulse sequence parameters, making it hard to include the technique in large multi-centre clinical trials. The variations can be reduced by a normalisation procedure based on the flip angle and timing of the presaturation pulse, but correction for parameters such as saturation pulse shape, amplitude, duration and offset frequency remains problematic. We have defined a standard pulse sequence, to include a standard presaturation pulse and set of parameters, which can be implemented on scanners from both General Electric and Siemens, and has also been used on Phillips scanners. To validate the sequence and parameters, six European centres measured MTR in the frontal white matter of normal volunteers. It was possible to measure MTR values in controls which were consistent to within approximately +/-2.5 percentage units across sites. This degree of precision may be adequate in many situations. The remaining differences between sites and manufacturers are probably caused by B1 errors.

Item Type: Article
Keywords: Brain/ anatomy & histology Equipment Failure Analysis/ instrumentation/methods/ standards Europe Humans Image Interpretation, Computer-Assisted/ instrumentation/ standards Magnetic Resonance Imaging/ instrumentation/ standards Reference Standards Reproducibility of Results Sensitivity and Specificity Signal Processing, Computer-Assisted/ instrumentation
Schools and Departments: Brighton and Sussex Medical School > Brighton and Sussex Medical School
Depositing User: Paul Stephen Tofts
Date Deposited: 28 Feb 2007
Last Modified: 30 Nov 2012 16:50
URI: http://sro.sussex.ac.uk/id/eprint/809
Google Scholar:12 Citations
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