Does Lower-Limb Segmentation of DXA Matter in Sarcopenia?

Whole-body dual-energy X-ray absorptiometry (DXA) is widely used to assess muscle mass in older adults and serves as a reference method for sarcopenia diagnosis.1 Appendicular skeletal muscle mass, normalized to height squared, plays a central role in most contemporary diagnostic algorithms.2,3 Yet, despite its clinical importance, the anatomic assumptions underlying automated appendicular segmentation on DXA are rarely questioned.