Factors affecting 39 K NMR detectability in rat tissue

In this study we have found that NMR detectability of 39 K in rat thigh muscle may be substantially higher (up to 100% of total tissue potassium) than values previously reported of around 40%. The signal was found to consist of two superimposed components, one broad and one narrow, of approximately equal area. Investigations involving improvements in spectral parameters such as signal‐to‐noise ratio and baseline roll, together with computer simulations of spectra, show that the quality of the spectra has a major effect on the amount of signal detected, which is largely due to the loss of detectability of the broad signal component. In particular, lower‐field spectrometers using conventional probes and detection methods generally have poorer signal‐to‐noise and worse baseline roll artifacts, which make detection of a broad component of the muscle signal difficult. © 1991 Academic Press, Inc.