Answer
The primary role of imaging in RA of the hands and wrists is to exclude septic arthritis. Percutaneous ultrasonography-guided aspiration may be useful for localizing and obtaining samples of any collection that can be found. (See the image below.)
Ultrasonography-guided synovial biopsy of the second metacarpophalangeal joint of the right hand in a patient with rheumatoid arthritis of the hands. The biopsy needle is seen as a straight echogenic line on the left side of the image in an oblique orientation.
Radiography remains the first choice in imaging RA. Radiography is cheap, is easily reproducible, and allows easy serial comparison for assessment of disease progression. The main disadvantage is the absence of specific radiographic findings in early disease, since visualization of erosions may only be seen later. [1]
Magnetic resonance imaging (MRI) provides a more accurate assessment, as well as earlier detection of lesions. Magnetic resonance imaging (MRI) continues to develop as a treatment tool, with the main thrust being detection of early disease at a stage at which disease-modifying drugs can be used; however, the cost of the examination and the small size of the joints involved limit widespread use. With further experience and cheaper scans, MRI scanning for the treatment of RA may gain acceptance in the future. [2, 1, 3, 4, 5]
Ultrasonography of specific joints based on radiographs may have a role as well. [2, 6]
RA may occur as part of a mixed connective tissue disease in which clinical and radiologic appearances are not typical of one particular disease.
-
Soft-tissue swelling and early erosions in the proximal interphalangeal joints in a patient with rheumatoid arthritis of the hands.
-
Prominent juxta-articular osteopenia in all interphalangeal joints in a patient with rheumatoid arthritis of the hands.
-
Well-defined bony erosions in the carpal bones and metacarpal bases in a patient with rheumatoid arthritis of the hands.
-
Multiple erosions with deformity of the carpal bones in a patient with rheumatoid arthritis of the hands.
-
Follow-up radiograph obtained after an 18-month interval in a patient with rheumatoid arthritis of the hands. Ankylosis of the carpal bones has occurred, with enlargement of the erosions.
-
Subluxation in the metacarpophalangeal joints, with ulnar deviation, in a patient with rheumatoid arthritis of the hands.
-
Subluxation at the third metacarpophalangeal joint and marginal erosions at the heads of the second to fourth metacarpals in a patient with rheumatoid arthritis of the hands.
-
Marked ankylosis of most of the carpal bones in a patient with rheumatoid arthritis of the hands.
-
Partial collapse of fused carpal bones with subluxation at the radiocarpal joint in a patient with rheumatoid arthritis of the hands.
-
Coronal fine-section gradient echo MR image demonstrates multiple erosions in the carpal bones and bases of the metacarpals, with pannus formation around the distal ulna.
-
Axial proton-density weighted MR image at the level of the radio-carpal joint shows extensive tenosynovitis involving the dorsal extensor and volar flexor tendons, with fluid in the tendon sheaths.
-
Axial T2-weighted fat-suppresed MR image at the level of the carpal bones shows diffuse synovial hypertrophy over the dorsal aspect (arrows), with a heterogenous appearance and adjacent fluid. Fluid is also present in the dorsal extensor tendon sheaths.
-
Axial T1-weighted MR image of the wrist before and after gadolinium administration shows diffuse contrast enhancement in the areas of synovial hypertrophy and thickening, over both the dorsal and volar aspects.
-
Illustration of the scanning technique. Photograph depicts the typical scanning technique with application of the Entos Probe to the volar (flexor) aspect of the third metacarpophalangeal joint. The technique allows visualization of the joint surfaces, flexor tendon, and synovial sheaths in patients with rheumatoid arthritis.
-
Amplitude color Doppler sonogram in a patient with active rheumatoid arthritis. Dorsal (extensor) surface of the second metacarpophalangeal joint is imaged. Intense-amplitude Doppler color flow signal demarcates the inflamed synovium (ie, joint pannus) resulting from severe hyperemia. Solid arrows indicate the extensor tendon sheath and dorsal and volar margins. Straight open arrow indicates the synovium of the joint overlying the proximal phalanx of the second digit. Curved open arrow indicates the inflamed synovium overlying the metacarpal. The asterisk indicates a small amount of anechoic fluid in the joint space.
-
Power Doppler image shows hyperemic blood flow in the flexor tendon sheath in a patient with rheumatoid arthritis of the hands.
-
Ultrasonography-guided synovial biopsy of the second metacarpophalangeal joint of the right hand in a patient with rheumatoid arthritis of the hands. The biopsy needle is seen as a straight echogenic line on the left side of the image in an oblique orientation.
