Interpretation of magnetization transfer and proton cross-relaxation spectra of biological tissues.

Magnetization-transfer (MT) experiments have been performed at 300 MHz on agar gels, solutions of sodium alginate, bovine nasal cartilage, and postmortem porcine muscle. The experimental results elucidate MT mechanisms between mobile macromolecules (correlation time TC on the order of 10(-8) s) and water, and demonstrate the need to incorporate their effects in the characterization of biological samples. In addition, the results obtained confirm a recently published three-spin-bath theoretical treatment for proton magnetization transfer.