[(11)C]acetate PET/CT Visualizes Skeletal Muscle Exercise Participation, Impaired Function, and Recovery after Hip Arthroplasty; First Results

PURPOSE: Based on skeletal muscle acetate physiology we aimed studying muscle function after hip arthroplasty with [(11)C]acetate PET. PROCEDURES: Two male patients were investigated 3 and 12 weeks after hip arthroplasty with muscle [(11)C]acetate PET/CT performed at rest and exercise. Median muscle SUV(mean) were calculated on three non-consecutive transverse PET slices. RESULTS: The four exercise PET/CT showed, compared with rest, consistent increase in [(11)C]acetate uptake in active muscles contralateral to surgery. On the arthroplasty side most muscles showed symmetric activity increase under exercise both at 3 and 12 weeks after surgery, but four muscles showed only minor activity increase at 3 weeks. At 3 months, functional recovery of the latter four muscles was observed. CONCLUSION: Consistent increase in [(11)C]acetate uptake in healthy muscles under exercise compared with rest was observed by PET/CT. Transiently impaired muscle function 3 weeks after surgery recovered at 3 months. These first observations merit further investigation.