Abstract
Purpose
To study the apparent heterogeneous characteristics of trimethyl ammonium (TMA) in healthy human muscles at rest, and to illustrate the importance of establishing the baseline characteristics of proton metabolites in muscles with a West Nile patient.
Materials and Methods
Pointβresolved spectroscopy (PRESS) magnetic resonance spectroscopy imaging (MRSI) with lipid suppression and optional outerβvolume presaturation were used to acquire ^1^H spectra of human muscles at rest at 1.5 Tesla. A total of 28 subjects (27 normal volunteers and 1 patient with West Nile disease) between the ages of 22 and 76 participated in the study.
Results
The apparent T~2~ values of TMA for soleus and gastrocnemius muscles in normal volunteers are 180 Β± 50 and 80 Β± 20 msec, respectively. This difference has profound effects on the apparent spectral pattern of ^1^H metabolites. The TMA/total creatine (tCr) spectral pattern of the soleus muscle of a West Nile patient resembles that of gastrocnemius muscle of healthy volunteers.
Conclusion
There are significant differences in the apparent T~2~ values of TMA between healthy soleus and gastrocnemius muscles at rest. It is important to establish the baseline characteristics of proton metabolites before clinical or physiological studies can be performed. J. Magn. Reson. Imaging 2004;19:617β622. Β© 2004 WileyβLiss, Inc.