Muscle Imaging Assessments in Sarcopenia: A Statement from China National Center for Orthopedics (NCO) and the East Meets West Action Group of the European Calcified Tissue Society (ECTS).

Sarcopenia, characterized by progressive loss of muscle mass, strength, and function, significantly impacts patient outcomes. Accurate assessment of muscle mass is essential for its diagnosis. Currently the agreement on how to use imaging for sarcopenia detection is still debated and how well the muscle imaging assessments correlate with muscle function needs further agreement. Recognizing the critical role of imaging in this process, the China National Center for Orthopedics (NCO) and the East Meets West Action Group of European Calcified Tissue Society (ECTS) convened a working group endorsed by the Board of the ECTS. This paper aims to evaluate the utility of various imaging techniques for diagnosing sarcopenia and understanding its functional consequences. We synthesize evidence on DXA, BIA, CT, MRI and ultrasound, and provide specific related recommendations. Imaging cannot replace functional assessments, but may enhance them by revealing subclinical disease, clarifying pathophysiology, and enabling individualized care. We hope to assist clinicians and researchers in using imaging to improve sarcopenia diagnosis, prognosis, and therapeutic monitoring, while also advocating for evidence-based structural and functional criteria in future guidelines.