Continuous-wave magnetic resonance imaging of short T-2 materials

There is growing interest in the use of magnetic resonance imaging (MRI) to examine solid materials where the restricted motion of the probed spins le ads to broad lines and short T-2 values, rendering many interesting systems invisible to conventional 2DFT pulsed imaging methods. In EPR T-2 seldom e xceeds 0.1 mus and continuous-wave methods are adopted far spectroscopy and imaging. In this paper we demonstrate the use of continuous-wave MRI to ob tain 2-dimensional images of short T-2 samples. The prototype system can im age samples up to 50 mm in diameter by 60 mm long and has been used to imag e polymers and water penetration in porous media. Typical acquisition times range between 10 and 40 min. Resolution of 1 to 2 mm has been achieved far samples with T-2 values ranging from 38 to 750 mus. There is the possibili ty of producing image contrast that is determined by the material propertie s of the sample, (C) 2001 Academic Press.