Validity of Musculoskeletal Ultrasonography for the Assessment of Muscle Mass in Older Adults: A Systematic Review and Comparative Meta‐Analysis With DXA
Clara Takako Moriguchi, Jordana Soares Chaves, Matheus de Lima Ruffini, Lucas De Liz Alves, Isabella Passos Negreiros, Adolfo Moraes de Souza, Laís Helena Gomes Cordeiro, Mariana Matheus Silveira, Diego Pires De Moura, Fabiano Reis, Juliana Ávila DuarteABSTRACT
Introduction
Sarcopenia is a progressive skeletal muscle disorder associated with adverse clinical outcomes, including functional decline, frailty, and mortality in older adults. Although dual‐energy X‐ray absorptiometry (DXA) is recommended as the reference method for the assessment of muscle mass, its limited availability restricts widespread clinical implementation. Musculoskeletal ultrasonography (US) has emerged as a promising alternative due to its portability, low cost, and absence of ionizing radiation; however, its validity relative to DXA in older populations remains insufficiently synthesized.
Methods
A systematic review and meta‐analysis was conducted in accordance with PRISMA 2020 and registered in PROSPERO (CRD420251168461). Six databases were searched (2015–2025) for observational studies comparing US with DXA in adults aged ≥ 60 years. Risk of bias was assessed using QUADAS‐2, and US protocols were evaluated using Pretorius and Keating criteria. Random‐effects meta‐analyses (REML with Knapp–Hartung adjustment) were performed to pool correlation coefficients and diagnostic accuracy outcomes.
Results
Nineteen studies were included in the qualitative synthesis. Nine studies contributed to the meta‐analysis of correlation coefficients, while 12 contributed to quantitative summaries across outcomes. Ultrasonographic parameters showed a strong association with DXA‐derived lean mass ( r = 0.855; 95% CI: 0.637–0.946), although heterogeneity was high ( I 2 = 97.4%). Inter‐rater reliability was excellent (ICC: 0.90–0.98). Diagnostic performance was acceptable to good (AUC: 0.75–0.95), with higher specificity than sensitivity (median: 0.91 vs. 0.74), supporting ultrasound mainly as a complementary or confirmatory tool rather than a stand‐alone screening method.
Conclusion
Musculoskeletal US is a highly correlated and reproducible tool, representing a practical option for muscle assessment and a useful complementary method for clinical evaluation and longitudinal monitoring, particularly given its high specificity. However, it should not replace DXA for formal diagnosis due to methodological heterogeneity and moderate sensitivity, highlighting the need for protocol standardization and the establishment of diagnostic cut‐off values to support its integration into routine geriatric practice.