The primacy of ultrasound in the assessment of muscle architecture: Precision, accuracy, reliability of ultrasonography. Physiatrist, radiologist, general internist, and family practitioner’s experiences

OBJECTIVE: With high-resolution real-time ultrasonography we investigated the muscle architectural parameters of vastus lateralis in healthy volunteers. PURPOSES: We determined the reproducibility and validity of ultrasonography and the role of the ultrasonographer in assessing muscle architecture. We proposed the most appropriate clinical parameters for objective measurements and an ultrasound protocol of muscle architecture. METHODS: We conducted an intraobserver and interobserver study. We investigated 21 healthy male volunteers. The subjects were independently evaluated by four different operators using high-resolution real-time ultrasonography. To assess the reproducibility of ultrasound examinations, four operators repeated measurements using the same ultrasound device. Muscle thickness, muscle volume, muscle fiber pennation angle, and subcutaneous adiposity of the vastus lateralis muscle were measured. RESULTS: Intra-observer (ICC 0.92-0.97), interobserver (ICC 0.78-0.92) reproducibility was good to excellent for all measurements. CONCLUSION: Simple, reproducible, non-invasive ultrasound measurements of muscle structure easily demonstrated differences in muscle morphology. With a protocol and with objective and repeatable measurements, sonographers from different backgrounds could obtain an objective measurement of ultrasound images with little differences and low variability in results, thanks to the upgrading of diagnostic ultrasound imaging and their clinical skills.