This long-axis ultrasound image of the first wrist compartment shows findings consistent with de Quervain tendinopathy, most notably thickening of the extensor retinaculum (thick arrow). Deep to the retinaculum, tendon fibers (asterisk), primarily of the extensor pollicis brevis based on probe position, are seen. The hyperechoic distal radius (bright curving line) is seen deep to the tendon (arrows).
