Quantitative shear wave elastography compared to standard ultrasound (qualitative B-mode grayscale sonography and quantitative power Doppler) for evaluation of achillotendinopathy in treatment-naïve individuals: A cross-sectional study.

Abstract

Achillotendinopathy is reported as an overuse disorder and/or degeneration change of the tendon. The diagnosis of tendinopathy is not always easy through imaging modalities. The B-mode grayscale sonography and power Doppler are well-established methods aimed at visualising tendon structure, but have limited sensitivity and lack conventional sonographic characteristics in symptomatic patients. Shear wave ultrasound elastography quantitatively assesses tissue stiffness. To compare the diagnostic accuracy of shear wave ultrasound elastography to that of standard ultrasound (combined B-mode grayscale sonography and power Doppler) for diagnosis of achillotendinopathy, considering clinical symptoms as the reference standard. Standard questionnaires regarding medical history and the Chinese version of a Victorian Institute of Sports Assessment - Achilles Questionnaires (VISA-AC) score were evaluated for a total of 14 treatment-naïve patients with complaints of localized swelling, and reduced force and/or flexibility of the Achilles tendon(s). The irregular thickening around the Achilles tendon, heterogeneity of echotexture of the tendon and calcification of the calcaneal attachment were considered incidences of tendinopathy in B-mode grayscale sonography. Tendinopathies were considered if tendons were >0.60 cm thick in power Doppler. Shear wave elasticity <350 kpa (10 m/s) was considered tendinopathy. A total of 28 conditions of both sides were evaluated through standard ultrasound examinations. Eighty-four tendons were assessed using shear wave ultrasound elastography. Asymptomatic tendons were visible as red and symptomatic (VISA-AC score <80) tendons were visible as blue or turquoise in the images. The rigidity of symptomatic tendons was lower than that of asymptomatic tendons (p < 0.0001). Sensitivity and accuracy for standard ultrasound were increased by the addition of shear wave ultrasound elastography for both symptomatic and asymptomatic tendons. The VISA-AC score was strongly correlated with the elasticity values (p = 0.000, Kendall's tau-beta (τβ) = 0.71) of Achilles tendons. Shear wave ultrasound elastography augments diagnostic confidence of standard ultrasound for the treatment of tendinopathies of Achilles tendons.