Clinical differentiation among tendinopathy, partial tears, and paratendinitis is challenging, and imaging is needed to make a definite diagnosis. The main modalities used to do this are ultrasound and/or MRI,^13-15 but both have proved controversial. Ultrasound has the advantage of dynamic imaging, which allows for better detection of adhesions and fiber dehiscence in partial tears compared with MRI. On the other hand, MRI enables the better detection of increased fluid (edema) that may be present in tendinosis.

ASSESSMENT OF PERFORMANCE

We investigated the performance of RTSE in the detection of Achilles tendinopathy and lateral epicondylitis (tennis elbow). All examinations were performed using a linear array transducer with a frequency of 6 to 13 MHz. We used an EUB-8500 ultrasound system when examining the Achilles tendon and an EUB-9000 system when studying the elbow (Hitachi Medical). Tissue elasticity distributions were calculated in real-time (up to 30 frames per second). Results were represented in color over the conventional B-mode image.⁵

We examined 80 Achilles tendons in healthy volunteers and 25 tendons in patients complaining of inflammation and pain in the Achilles region (achillodynia). Force applied to the Achilles tendon was adjusted appropriately according to the visual indicator for compression seen on the video screen. Local strain was computed under slight compression and decompression.

RTSE showed that the tendons normally had a hard structure, but that distinct softening had occurred in the patients' Achilles tendons (Figures 3 through 5).¹⁶ Alterations were most often observed in the midportion of the Achilles tendon (80%). RTSE had a mean sensitivity of 94%, specificity of 99%, and accuracy of 97% when compared with clinical examination. A strong correlation was found with conventional ultrasound findings (r = 0.89).