Cross polarization for 1H NMR image contrast in solids

A novel 1H imaging method for solids, yielding images reflecting 1H-13C dipolar interactions through cross relaxation time TIS, is presented. Phase-alternating multiple-contact cross polarization (PAMC CP) was incorporated into the magic-echo frequency-encoding imaging scheme; the PAMC CP sequence may partly but efficiently destroy the initial 1H magnetization depending on the TIS values. A theory describing the effects of the PAMC CP sequence was developed, which was used for the assessment of the sequence as well as the analysis for the experimental results. It was demonstrated that the TIS-weighted 1H image and the TIS mapping for a phantom, constituted of adamantane and ferrocene, can distinguish these compounds clearly. Copyright 1998 Academic Press.