Cross-sectional area of the cervical extensors assessed with panoramic ultrasound imaging: Preliminary data in healthy people.

BACKGROUND Studies analyzing morphometry of neck extensor musculature have mostly used Magnetic Resonance Imaging (MRI). Panoramic Ultrasound View could be used for obtaining high-quality 2D cross-sectional images with a wide field of view more cost-effectively imaging acquisition by creating an automatic construction of 2D cross-sectional images. OBJECTIVE To measure neck extensors cross-sectional area (CSA) using panoramic ultrasound view in healthy subjects. DESIGN Cross-sectional study. METHODS Panoramic B-mode ultrasound images of the neck extensor muscles at C4/C5 level were acquired in 25 healthy subjects (40% women, mean age: 24 ± 5 years) by an experienced assessor. The CSA of the upper trapezius, splenius (layer), semispinalis (layer), multifidi, short rotators, and levator scapulae were calculated. The relative percentage in the total neck extensor muscle volume of each CSA was also determined. Sex and side-to-side comparisons were conducted. RESULTS Men showed larger CSAs than women in all muscles (all, P   0.05). Significant positive associations between CSA with weight (r: 0.654 to 0.375, P < 0.01), height (r: 0.386 to 0.581, P < 0.05), and BMI (r: 0.369 to 0.563, P < 0.05) were found. Men showed greater percentage of upper trapezius and semispinalis muscle layers than women (P < 0.01), whereas women had a greater percentage of levator scapulae muscle than men (P < 0.01) from the total volume of the neck extensors. No side-to-side differences were found either. CONCLUSIONS The current study describes CSA, as assessed with panoramic ultrasound view, of the neck extensors in healthy people. Men exhibited greater CSA than women with no side-to-side differences.