MRI in inhomogeneous magnetic fields

Images of a phantom consisting of a glass capillary (0.9 and 1.6 mm for the inner and outer diameters) inserted in a sample tube (3.8 mm inner diameter), where the spaces are filled with water. Combinations of encoding and decoding schemes of increasing sophistication were tested from left to right, while the homogeneity of the static field was degraded from top to bottom.

Pulse sequence

Cross-encoded scheme designed to compensate for unknown inhomogeneities of the magnetic field. The signs of the gradients are alternated and the radio-frequency pulses are swept adiabatically.

Related publications

• Cross-Encoded Magnetic Resonance Imaging in Inhomogeneous Fields. R. Paquin, P. Pelupessy, and G. Bodenhausen, J. Magn. Reson. 201, 199-204 (2009).
• High-Resolution NMR in Magnetic Fields with Unknown Spatiotemporal Variations.P. Pelupessy, E. Rennella, and G. Bodenhausen, Science, 324, 1693-1697 (2009)