NMR Microscopy with isotropic resolution of 3.0 μm using dedicated hardware and optimized methods

Nuclear magnetic resonance microscopy at an isotropic resolution of 3.0 mu m was realized by using dedicated hardware such as RF surface microcoils, a planar triple-axis gradient with 6,500 G/cm, and a static magnetic field of 18.8 T. Purely phase-encoded constant time imaging was used to allow increasing the gradient strength for the suppression of diffusion effects without reducing the signal-to-noise ratio. For this method the relationship between gradient strength and true spatial resolution was investigated, and an empirical formula is provided that is useful for practical applications. The characteristics of the different hardware components were investigated experimentally. Furthermore, microscopic phantom images were acquired and evaluated for their true resolution. it is demonstrated that the use of sufficiently large gradients enables suppressing diffusion-related loss of spatial resolution. (C) 2008 Wiley Periodicals, Inc.