Extended field-of view sonography in Achilles tendon disease: A comparison with MR imaging

Purpose: To evaluate the role of real-time extended field-of-view sonography, (EFOVS) in symptomatic Achilles tendon disease in comparison with MR imaging (MRI). Materials and Methods: Twenty-three symptomatic tendons were examined by conventional grayscale sonography, EFOVS and MRI, which served as the gold standard. Results: The median tendon thickness in MRI was 7.8 mm (IQR 3.1) and correlated significantly to the results of EFOVS (7.0 mm, IQR 2; r = 0.74, P < 0.01). In total, MRI detected 24 lesions in 18 tendons and EFOVS 21 hypoechoic lesions in 15 tendons, corresponding to a sensitivity of 87.5% and specificity of 100%. The additional usage of conventional grayscale sonography improved sensitivity to 95.8%. The median distance of the largest lesion to the calcaneal tuberosity was 10.4 mm (IQR 3.4) in MRI and 8.5 mm (IQR 5.1) in EFOVS (r = 0.64; P < 0.05). The sensitivity and specificity of EFOVS for the detection of a peritendinitis were 63.6% and 66.7%, respectively. Corresponding values for the detection of a bursitis were 68.8% and 28.6%. The additional usage of conventional grayscale sonography improved the specificity to 85.7%. Conclusion: The combination of EFOVS and grayscale sonography has the potential to challenge MRI as the preferred imaging method in diagnosing symptomatic Achilles tendon disease, especially with respect to saving time and cost and the absence of any contraindications.