Real-time sonoelastography findings in healthy Achilles tendons

Real-time sonoelastography is a new ultrasound-based technique able to assess tissue elasticity that has already shown feasibility in tumor diagnosis. The aim of this study was to assess the performance of real-time sonoelastography in depicting the Achilles tendons of healthy volunteers and to compare sonoelastography findings with conventional ultrasound findings.

Eighty asymptomatic Achilles tendons of 40 healthy volunteers (19 men, 21 women; mean age, 38 years; range, 20-76 years) were examined on real-time sonoelastography and ultrasound. The Achilles tendons were divided into the following thirds for image evaluation: proximal (musculotendinous junction), middle (2-6 cm above insertion at the calcaneus), and distal (insertion at the calcaneus). Longitudinal and axial images of each tendon third were obtained using ultrasound and real-time sonoelastography. Real-time sonoelastography images were evaluated by reviewers using an experimentally proven color grading system.

The Achilles tendons showed mainly a hard structured pattern (86.7%) (208/240 tendon thirds) on sonoelastography; however, mild softening was found in 12.1% (29/240) of the tendons. Distinct softening corresponding to alterations found also on ultrasound and, therefore, suggesting subclinical changes was detected in 1.3% (3/240). The overall correlation (kappa) between real-time sonoelastography and ultrasound findings was 1.00.

In healthy volunteers, the Achilles tendon appeared hard on real-time sonoelastography with excellent correlation to ultrasound. Further investigation including pathologic tendons should be performed to prove the value of real-time sonoelastography in the assessment of Achilles tendinopathy.