Background: Sarcopenia, the age-related loss of muscle mass, increases health risks in older adults. Accurate measurement of skeletal muscle mass is critical for diagnosis. While DEXA is widely used, its extended scan time limits clinical utility. This study evaluates the accuracy of lean mass measurements from the newly developed iNSiGHT C510 X-ray bone densitometer compared to MRI, the gold standard.

Methods: This single-center, open-label clinical trial included 20 adult participants (10 males, 10 females) aged 20–70 years. Participants underwent whole-body scans using the iNSiGHT C510 and MRI. Lean and fat mass measurements were obtained from both devices. Statistical analysis included Bland-Altman plots, intraclass correlation coefficients (ICC), and concordance correlation coefficients (CCC) to assess agreement between the two methods. Linear regression analysis was performed to derive conversion formulas between C510 and MRI measurements.

Results: The study found a very strong correlation between lean mass measurements from the iNSiGHT C510 and MRI, with correlation coefficients (r) of 0.961 for the right side, 0.967 for the left, and 0.963 for combined lean mass. ICC and CCC values for lean mass were also high, indicating strong agreement between the two methods. Fat mass measurements, though moderately correlated, showed larger discrepancies compared to lean mass. The iNSiGHT C510 significantly reduced measurement time by 50 % compared to conventional DEXA scans.

Conclusion: The iNSiGHT C510 demonstrated high accuracy in measuring lean mass compared to MRI, with the added benefit of shorter measurement time, making it a practical tool for sarcopenia diagnosis and monitoring in clinical settings. However, further research with larger sample sizes and long-term assessments is needed to validate its broader clinical utility.