Traditional MRI techniques rely on close proximity between the sample and detector to produce high resolution images. Klaas Pruessmann and colleagues, at ETH Zurich, have shown that the nuclear magnetisation signal used to create these images can be excited and detected over a longer range — using travelling radio-frequency waves. These waves can be guided by installing a specialised conductive lining in the machine. This allows both the source and detector to be situated at the end of the magnet and frees up space in the centre of the machine for the subject.
As well as offering greater comfort, the new approach can provide more uniform coverage over larger samples, biological or otherwise. And having more space offers the opportunity to position additional equipment, such as stimulation devices for studies of brain function. The authors hope their new technique will permit the design of experiments that were not possible before.
The team’s research was published in Nature (pp 994-998; N&V).