Microstructured magnetic materials for RF flux guides in magnetic resonance imaging

Magnetic resonance imaging and spectroscopy systems use coils, either singl y or as arrays, to intercept radio-frequency (RF) magnetic flux from region s of interest, often deep within the body. Here, we show that a new magneti c material offers novel possibilities for guiding RF flux to the receiver c oil, permitting a clear image to be obtained where none might otherwise be detectable. The new material contains microstructure designed according to concepts taken from the field of photonic band gap materials. In the RF ran ge, it has a magnetic permeability that can be produced to specification wh ile exhibiting negligible direct-current magnetism, The latter property is vital to avoid perturbing the static and audio-frequency magnetic fields ne eded to obtain image and spectral data. The concept offers a new paradigm f or the manipulation of RF flux in all nuclear magnetic resonance systems.