2. Dorsal view

Figure 1. Dorsal view, transverse plane. ECU: m. extensor carpi ulnaris, EDM: m. extensor digiti minimi, EDC: m. extensor digitorum communis, EI: m. extensor indicis, EPL: m. extensor pollicis longus, ECRB: m. extensor carpi radialis brevis, ECRL: m. extensor carpi radialis longus, EPB: m. extensor pollicis brevis, APL: m. abductor pollicis longus

Transverse ultrasound section of the dorsal aspect of the wrist at the level of the distal radius. In this projection, all six extensor compartments can be clearly visualized, from the ulnarly located tendon of the m. extensor carpi ulnaris to the radially located tendons of the first compartment, particularly the m. abductor pollicis longus and m. extensor pollicis brevis; between them, the tendons of other extensors running over the distal radius and ulna are also visible. This projection is essential for the orientation assessment of extensor compartments and for the detection of tenosynovitis, subluxations, and degenerative changes of tendons in the dorsal wrist area.

Figure 2. Dorsal view, transverse plane. ECRB: m. extensor carpi radialis brevis, ECRL: m. extensor carpi radialis longus

Transverse ultrasound section of the dorsoradial portion of the wrist showing the second extensor compartment, located lateral to Lister's tubercle. In this view, the tendons of m. extensor carpi radialis brevis (ECRB) and m. extensor carpi radialis longus (ECRL) are visible, running close to the dorsal contour of the distal radius. This area is a common site of overuse and this view is important for evaluating tenosynovitis, irritative changes, and other pathological changes of the tendons of the second extensor compartment.

Figure 3. Dorsal view, transverse plane. EPB: m. extensor pollicis brevis, APL: m. abductor pollicis longus

Transverse ultrasound section of the dorsoradial part of the wrist showing the first extensor compartment. In this projection, the tendons of m. abductor pollicis longus (APL) and m. extensor pollicis brevis (EPB) are visible, running in a common tendon sheath over the radial styloid. This projection is typical for assessment of De Quervain's tenosynovitis and allows evaluation of sheath thickening, presence of fluid, and other signs of overuse in the first extensor compartment area.

Figure 4 Dorsal view, transverse plane. ECU: m. extensor carpi ulnaris

Transverse ultrasound section of the dorsoulnar part of the wrist showing the sixth extensor compartment located over the ulna. In this projection, the extensor carpi ulnaris (ECU) tendon is visible, running in the ulnar groove as the main structure of this compartment. This projection is essential for evaluating tenosynovitis, instability and subluxation of the ECU tendon, especially during dynamic examination in connection with ulnar wrist pain.

Figure 5. Dorsal view, sagittal plane.

Longitudinal ultrasound section of the dorsal side of the wrist showing extensor tendons in long axis above the radiocarpal joint. In this projection, extensor tendons are visible as fibrillar structures running superficially over the contour of the distal radius and carpal bones, with the imaging also including the radiocarpal joint area. This projection is important for detecting joint effusion, signs of synovitis, and for evaluating continuity of extensor tendons when partial or complete tendon injury is suspected.