Hypoechoic retinacular thickening involving the 1st extensor compartment and minor effusion distally. Both tendons are intact with a normal echopattern.
An extra-structure with muscle echopattern is present deep to the 4th extensor compartment. It starts at the carpal level and ends at the 3rd and 4th metacarpal distal shaft levels.
A structure with similar morphology is present in the contralateral dorsal wrist.