ABSTRACT
Biological tissue is relatively transparent to electromagnetic radiation with fre quencies in the megahertz or radio-frequency (RF) range. Nuclear magnetic reso nance (NMR) techniques utilize this property to obtain various anatomical, biochemical, and physiological information from tissue. Magnetic resonance imaging (MRI) of protons (Ή) is now a widely accepted clinical imaging modal ity, primarily due to its ability to image soft tissue like the white matter and grey matter of the brain. But apart from Ή MRI, NMR can interrogate many other nuclei in the tissue. A list of isotopes of the elements that have been studied in biological samples by NMR is given in Table 10.1 in order of decreasing absolute sensitivity.