OBJECTIVETo compare MR imaging with radiographs in detection of the erosions of the wrists in patients with rheumatoid arthritis (RA).

METHODSIn 50 wrists of 25 patients with RA, radiographs of AP projection and MR imaging examination were performed within 1 week. The MRI sequences were SE T1-weighted image, FSE T2-weighted image, and GE T2* weighted image in coronal plane. Gd-DTPA enhanced SE T1-weighted image with same parameters of pre-contrast administration SE T1WI was performed in 25 wrists, which showed prominent lesions in each 25 patients.

RESULTSIn 50 wrists of 25 patients with RA, bone erosions were found by MR images compared to radiographs in 46 versus 14 wrists, respectively. There were 170 sites of carpal erosions found by MR images, while radiographs found only 23 sites of carpal erosions. Among them triquetrum and lunate were the most frequently involved sites. Significant difference (P < 0.001) was statistically found between conventional radiography and MR imaging in detection of erosions of the wrists of RA. MR imaging also permitted demonstrating synovitis and joint effusion in the wrists. Gd-DTPA-enhanced images allowed distinguishing pannus changes from joint effusion.

CONCLUSIONMRI is superior to conventional radiography with respect to detection of bone erosion in wrists. For those whose conventional radiographs show suspected RA, MRI examination should be advised for the early diagnosis.