Rheumatoid tenosynovitis with rice-body formation
The MRI shows marked thickening of the extensor carpi ulnaris
tendon associated with tenosynovitis (Figure 1). Also, within the
tendon sheath are several oblong structures, which are
predominantly low in signal on T2-weighted (T2W) images (Figure 2).
Rice-body formation is a nonspecific response to chronic synovial
inflammation, which was first described in association with
Since then, rice-body formation
has been associated with both rheumatoid arthritis and juvenile
rheumatoid arthritis. The pathogenesis of rice-body formation
remains controversial but may be related to microinfarction of the
with release of tissue into the joint or
detachment of hypertrophied synovium.3
The MRI characteristics have been well documented with
well-defined nodules of intermediate signal on T1-weighted (T1W)
images that are relatively low in signal on T2W
sequences.4 Although synovial osteochondromatosis and
pigmented villonodular synovitis arearthropathies associated with
low-signal structures around joints, tendons, and bursa, these 2
entities more commonly occur as monoarticular processes and are
more often seen in larger joints, such as the knee or hip.
Additionally, there is no evidence of hemosiderin deposition to
suggest pigmented villonodular synovitis, and the cartilage
components in synovial osteochondromatosis are high in signal on
T2W images. The fact that the patient had a similar abnormality at
a different site should suggest the possibility of a systemic
Rice-body formation has a characteristic appearance on MRI,
manifesting as masses of intermediate signal on T1W images and low
signal on T2W images. Their presence should alert the radiologist
to the possibility of an inflammatory arthropathy.
- Riese H. Die reiskorperchen in tuberculkoserkrankten
synovalsacken. Deut Zeit Chirurg. 1895;42:1-99.
- Cheung HS, Ryan LM, Kozin F, McCarty DJ. Synovial origins of
rice bodies in joint fluid. Arthritis Rheum. 1980;23:72-76.
- Berg E, Wainwright R, Barton B, et al. On the nature of
rheumatoid rice bodies: An immunologic, histochemical, and electron
microscope study. Arthritis Rheum. 1977;20:1343-1349.
- Chung C, Coley BD, Martin LC. Rice bodies in juvenile
rheumatoid arthritis. AJR Am J Roentgenol. 1998;170:698-700.