Muscle echo intensity: reliability and conditioning factors.

Objective: To assess the issue of muscle echo intensity reliability and to investigate the relationship between muscle echo intensity and size, shape and location of the region of interest (ROI) used for echo intensity quantification.

Methods: Ultrasonographic scans of the following five muscles were acquired in twenty healthy subjects: biceps brachii, rectus femoris, vastus lateralis, tibialis anterior and medial gastrocnemius. Muscle echo intensity was quantified in each scan.