New normal values for quantitative muscle ultrasound: obesity increases muscle echo intensity.

摘要

Muscle ultrasound is a useful technique to detect neuro-muscular disorders (NMDs) because it can visualize structural changes such as atrophy and intramuscular fat and fi-brosis. Some neuromuscular disorders are characterized by specific patterns of muscle involvement.2 Normal values of muscle thickness and muscle echo intensity of various skeletal muscles are helpful in diagnosing NMDs, but until now were only available for a few muscles (tibialis anterior, rectus femoris, biceps brachii, and forearm flexors). In this study, we established normal values for 7 muscles (vastus lateralis, rectus femoris, rectus abdominis, deltoid, first dorsal interosseous, extensor digitorum brevis, and gastrocnemius) in addition to the 5 muscles recently described by Arts and co-workers.3 Adding to previous work, these normal values will help facilitate spreading the use of muscle ultrasound as a new non-invasive diagnostic tool for neuromuscular disorders. Muscle thickness and echo intensity were quantitatively determined in 54 healthy volunteers (27 men and 27 women, ages 21-86 years) with an ultrasound device (Model IU22; Philips Healthcare, Best, The Netherlands). The study protocol and system settings are outlined in Table S1 (supplementary material). The same analysis was applied as in the study of Arts et al., using a stepwise linear regression model.