In vivo Li nuclear magnetic resonance study of lithiumpharmacokinetics and chemical shift imaging in psychiatric patients

Inorganic Pharmacology of Lithium

“…In nature, lithium occurs as a mixture of the two stable isotopes, 7 Li (92.58%) and 6 Li (7.42%), which may be distinguished using isotopic shift atomic absorption spectrometry (ISAAS), Neutron activation analysis, nuclear reactions with neutrons or with charged particles, , secondary-ion mass spectrometry (SIMS), and nuclear magnetic resonance (NMR) spectroscopy. , The latter is also capable of distinguishing between lithium in the intracellular and extracellular compartments either because of the associated spectral changes when a large anionic ‘shift reagent' is added , of as a consequence of the changed relaxation time ( t 1 ) induced by the different molecular environments within and without the cell 28 and using the modified inversion recovery (MIR) technique . NMR also has the additional advantage that it may be used for imaging. − …”

In vivo NMR of drugs

“…This result is of interest because the toxic symptoms took about a week to subside, a result that suggests that in vivo 7Li NMR could be used to relate toxic effects to residual brain concentration. Preliminary' spectroscopic imaging of the spatial distribution of Li in human brain has also been performed (19) and may shed light on the mechanisms of the therapeutic and toxic effects of Li. Antineoplastic agents.…”

In vivo NMR of drugs

“…Figure 4b shows serial results for the same subject after he was taken off of Li treatment because he developed a tremor (19). Initially the Li levels dropped rapidly.…”