Work was done to improve magnetic field stability in FFC. A new magnetic field sensor (NMR type) and a new electric current sensor were built and tested, for use in a magnet-control feedback loop. Computer simulations allowed optimisation of the control parameters on a “virtual instrument”.
A new FFC-NMR relaxometer prototype was constructed, incorporating a new type of power supply. The relaxometer is compatible with new methods for automatic correction of environmental magnetic fields, developed during the project. Existing relaxometers within the consortium were upgraded to facilitate cross-partner working; one was fitted with a wide-bore magnet and surface-coil to expand its range of applications.
FFC-MRI needs to operate at extremely low magnetic fields. For operation below the Earth’s magnetic field, instrumentation was developed for accurate measurement of environmental magnetic fields and their cancellation. Magnetic field maps, aided by a mathematical model, resulted in optimised methods to cancel unwanted environmental fields.
Control hardware and software were improved so that the prototype FFC-MRI scanner is more flexible, easier to operate, and less prone to image artefacts. Improvements in image quality have arisen from better radiofrequency coils and electronics. Methods to speed up FFC-MRI were implemented, allowing a patient to be scanned in 45 minutes.
Theoretical models of low-field relaxation were developed to predict the shapes of dispersion curves, under different conditions. Computer programs were written for the analysis of dispersion data; this approach generated reliable, quantitative “biomarkers” of disease.
Work was carried out to investigate the potential of contrast agents for FFC-MRI, exploiting the dispersion at low field. Studies of new FFC-MRI contrast agents containing manganese were carried out, while the potential of novel agents exploiting quadrupolar relaxation effects was investigated. Studies on model tumours have investigated how low-field dispersion measurements of existing agents, already approved for human use, are altered by the tumour environment.
Studies investigated the ability of FFC-NMR to differentiate between normal and diseased tissues; many diseased tissues (e.g. brain cancers and colorectal cancers) exhibit significantly different dispersion curves than their normal counterparts.
Studies of patients took place, representing the world's first-ever clinical use of FFC-MRI, using the prototype scanner in Partner 1. These studies showed that stroke-affected brain tissue can be seen very clearly by FFC-MRI, when the scanner is switched to its lowest magnetic field (barely higher than the Earth's field). Studies of patients with brain cancer and patients with breast cancer have also been carried out.
The project has resulted in 22 peer-reviewed publications, 3 book chapters and 86 presentations at scientific conferences. Two one-day Symposia on FFC-MRI were organised and a wide range of public-engagement activities took place during IDentIFY. All outputs from the project are listed at
http://www.identify-project.eu/(odnośnik otworzy się w nowym oknie).
