Quantitative Muscle Ultrasound Device and Setting Selection for the SwallowDM1 study

Supplementary Material 1: Ultrasound Device Selection and Calibration ProtocolUltrasound echogenicity values are inherently device- and setting-dependent, making standardised device selection and calibration essential to the validity and reproducibility of quantitative muscle ultrasound (QMUS) measurements. Inconsistencies in equipment or configuration can introduce systematic error, confounding interpretation of muscle architecture and tissue composition. This supplementary document details the rationale and procedures for device and setting selection employed in the SwallowDM1 study, ensuring methodological transparency and facilitating replication by future investigators.