[¹¹C]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 [¹¹C]acetate PET. Procedures: Two male patients were investigated 3 and 12 weeks after hip arthroplasty with muscle [¹¹C]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 [¹¹C] 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 [¹¹C]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.