Magnetic resonance imaging (MRI) and fast field-cycling (FFC) NMR are both well developed methods. The combination of these techniques, namely fast field-cycling magnetic resonance imaging (FFC-MRI) is much less well-known. Nevertheless, FFC-MRI has a number of significant applications and advantages over conventional techniques,and is being pursued in a number of laboratories. This article reviews the progress in FFC-MRI over the last two decades, particularly in the areas of Earth’s field and prepolarised MRI, as well as free radical imaging using field-cycling Overhauser MRI. Different approaches to magnet design for FFC-MRI are also described. The paper then goes on to discuss recent techniques and applications of FFC-MRI, including protein measurement via quadrupolar cross-relaxation, contrast agent studies, localised relaxometry and FFC-MRI with magnetisation-transfer contrast.
Bibliographical noteAcknowledgements The authors acknowledge financial support for the FFC-MRI project from Research Councils UK and the Engineering and Physical Sciences Research Council, under the Basic Technology scheme (grant No. EP/E036775/1)
- fast-field cycling magnetic resonance imaging
- Earth-field MRI
- pre-polarised MRI
- free-radical imaging
- magnetisation-transfer contrast