Use of Ultrasonography for Measuring Achilles Tendon Thickness: a Novel Measurement Method

Achilles tendon ultrasonography was performed on healthy volunteers included in the study by an emergency physician trained in both basic and advanced ultrasonography techniques. Measurements were conducted using a Butterfly iQ (Butterfly Network, Inc., Guilford, CT) ultrasound device in B-mode with a musculoskeletal preset, using biplane imaging. For Achilles tendon measurement, the image depth was set to 2.0 cm. A linear probe was placed longitudinally and perpendicular to the tendon. The distal portion of the Achilles tendon and the calcaneus were visualized in the long axis, whereas the short axis was used to center the Achilles tendon on the screen for an optimal measurement view. The measurement site was determined as 2 cm proximal to the Achilles tendon insertion at the calcaneus. In biplane imaging, Achilles tendon thickness was measured in the long axis, whereas thickness, width, and cross-sectional area were measured in the short axis. Measurements were performed bilaterally