Changes in Muscular Lipids in Unilateral Isolated Hypertrophy of Gastrocnemius Muscle Can Be Revealed by (1)H MR Spectroscopy

OBJECTIVE: To test whether proton magnetic resonance spectroscopy ((1)H-MRS) reveals changes in the lipid content of the gastrocnemius muscle (GM) and soleus muscle (SOL) of a patient with unilateral isolated hypertrophy of the right GM. MATERIALS AND METHODS: (1)H-MRS was performed on a 1.5 Tesla (T) whole-body unit. Muscular lipids inside SOL and GM were assessed in both calves of the patient by a STEAM (stimulated echo acquisition mode) localization sequence. Results were compared to a control group of four healthy volunteers. RESULTS: Total amount of muscular lipids in the hypertrophic GM of the patient was clearly increased compared to the controls (38.7 versus 21.8±3.5 a.u.) while intramyocellular lipids of the adjacent SOL were lower compared to the contralateral healthy leg. CONCLUSION: Muscular lipids are substrates for metabolism and can be assessed non-invasively by (1)H-MRS. (1)H-MRS is considered to be a helpful tool in clinical assessment of muscle metabolism in cases with muscular hypo- or hypertrophy.