Elasticity standard values of the Achilles tendon assessed with acoustic radiation force impulse elastography on healthy volunteers: a cross section study

Background: To determine normal values for acoustic radiation force impulse (ARFI) shear wave elastography of the Achilles tendon. Methods: Using the VTIQ mode with the Acuson S3000 T (Siemens Healthcare, Erlangen, Germany), we measured the shear wave velocity (SWV) in m/s and the diameter in mm of both Achilles tendons in 182 healthy volunteers. The tendon was displayed in a sagittal view with a relaxed tendon. The parameters were tested for correlations with the anthropometric data of the subjects, between the genders and different age groups, as well as information obtained from the history, such as smoking and sporting activities. Results: Using a sagittal acoustic window, we determined a mean SWV of 9.09 +/- 0.71 m/s for the left Achilles tendon and 9.17 +/- 0.61 m/s for the right. There was a significant difference between the results for the right and left side (p < 0.05). The diameter on the left was 4.7 +/- 0.9 mm. On the right, it was 4.8 +/- 0.9 mm. Likewise there was a significant difference between the results for the diameter of the left and right side (p < 0.05). Neither gender, body mass index (BMI) nor age had a significant effect on either of the measured parameters (p > 0.05). The same goes for the consumption of tobacco and alcohol (p > 0.05). Conclusions: Age, gender, BMI, smoking or the consumption of alcohol did not affect either the elasticity or the diameter of the Achilles tendon.