Clinical, radiological and magnetic resonance imaging in assessment of early rheumatoid arthritis

Abstract EN

Objective: To investigate the value of magnetic resonance imaging (MRI) with gadolinium contrast agent enhancement (Gd-DTPA) in monitoring of soft tissue and bone changes in the dominant hand of early rheumatoid arthritis (RA) patients.

Images were compared with conventional radiography, relating these changes to the clinical and laboratory findings.

Methods: Thirty-one patients (24 females and 7 males) with early RA, with disease duration <12 months, and no previous steroids or disease modifying anti-rheumatic drugs (DMARDs) were enrolled in the study (1999-2000).

All patients underwent a standard physical assessment at study entry and were investigated with laboratory tests and radiographic films for the dominant hand and wrist (assessed by one radiologist).

MRI imaging of the dominant hand and wrist was done in a 1.5T scanner (GE) machine.

T1, T1 post-Gad fat suppressed (FS) and T2 FS axial and coronal views were obtained and reviewed by another radiologist blinded with the results of physical or radiological assessment.

The results were documented and different groups were compared.

Results: The total number of erosions and cysts was significantly more detected with MRI than conventional radiology (p<0.01, p<0.05 respectively).

Taking joints individually, MRI proved superior to x-ray imaging by the significantly higher number of cysts in metacarpo-phalangeal (MCP) and wrist joints (p<0.05) and only the number of erosions in proximal interphalangeal (PIP) joints (p<0.01).

The number of patients with erosions was higher with MRI in PIP joints (p<0.05) and was not significant in the MCP and wrist joints.

The number of patients with cysts was higher by MRI in MCP and wrist joints (p<0.05, p<0.01 respectively).

MRI findings of synovitis and bone edema were significantly higher than tender joint count (p<0.001each).

The mean number of swollen joints was related to synovitis and bone edema (p <0.001, p<0.05 respectively), but was not related to the number of erosions or cysts.

There wasn’t any statistically significant correlation between the MRI findings and the erythrocytic sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF) or antinuclear antibodies (ANA).

However, there was a significant correlation between either bone edema or cysts and the grip strength (p <0.05), and a highly significant correlation between either synovitis or erosions and grip strength (p< 0.001, p <0.01 respectively).

Also, a highly significant correlation was found between the Ritchie articular index (RAI) and synovitis (p <0.001).

Conclusion: MRI of the hand is superior than x-ray radiography in detection of soft and hard tissue lesions in early cases of RA, especially cysts in MCP and wrist joints and erosions in PIP joints.

It has a great value in diagnosing clinically and non-clinically detectable synovitis and is the only way to detect bone edema around affected joints.