Portable Magnetic Resonance Devices
NMR A spinning magnet in a magnetic field will precess Larmor frequency ω = γ B Resonance – absorb energy Radio frequency for nuclei Energy decay, relaxation times T1 spin-lattice T2 spin-spin
Task 1 N uclear M agnetic R esonance What are the basic principles?
MRI Need spatial information to form image Magnetic gradients RF pulse sequences Phase encoding
Conventional MRI Uniform Magnetic field 1 part per million Field gradients superimposed to perturb field in defined way spatial information RF Pulse sequences image contrast combinations of relaxation times
Task 2 M agnetic R esonance I maging How did NMR develop into MRI? What are the essential requirements?
Hospital MRI Large - fills a room Expensive to buy ~£1M Expensive to run ~£100k p.a.
Hospital MRI Superb images High resolution Multipurpose
Idea – Portable! Permanent magnet Natural inhomogeneities (But not too much!) Local relaxation times (0D) images (1D, 2D, 3D)
Portable MR Small - suitcase? Cheap - ~£10s thousands Tailored for specific applications?
Task 3 M agnetic R esonance I maging Are there any uses for small (portable) MR devices? Work out the design specifications You might require for these applications.
Task 4 M agnetic R esonance I maging How can we make it small? Can you devise ways of meeting the design criteria of Task 3?
Task 5 M agnetic R esonance I maging Can you identify devices in which others have attempted to meet the challenge?
Aachen the MObile Universal Surface Explorer or the NMR-MOUSE ® Bernhard Blümich
Berkeley Portable High-Resolution NMR Sensor