Magnetic resonance imaging of the wrist and finger joints in patients with inflammatory joint diseases.

OBJECTIVE: To study magnetic resonance imaging (MRI) features in the wrist and metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints in 4 patient groups: early rheumatoid arthritis (RA) (< 3 yrs); established RA (> 3 yrs); other arthritis; arthralgia. METHODS: MRI was obtained before and after contrast (gadodiamide) injection of the wrist and finger joints in 103 patients and 7 controls. The study included: (1) 28 patients with disease duration < 3 yrs who fulfilled the American College of Rheumatology (ACR) criteria for RA; (2) 25 patients with RA disease duration > 3 yrs who fulfilled the ACR criteria. (3) 25 patients with reactive arthritis, psoriatic arthritis, or mixed connective tissue disease; and (4) 25 patients with arthralgia. The following MRI variables were assessed: number of joints with enhancement after contrast injection, number of joints with joint fluid, and number of bones with edema in the wrist and fingers. The volume of the enhancing synovial membrane after contrast injection in the MCP, PIP, and DIP joints was manually outlined. MR images were scored independently under blinded conditions. RESULTS: Bone marrow edema was found in 68% of the patients with established RA, and the number of bones with edema was significantly higher in patients with established RA compared to patients with early RA, other arthritis, and arthralgia (Mann-Whitney p < 0.04). Bone edema was not found in patients with arthralgia. There was marked overlap within and between the patient groups. No differences in MRI features were found between patients with early RA and patients with other arthritis. The volumes of the synovial membrane in the MCP, PIP, and DIP joints were significantly higher in patients with arthritis compared to patients with arthralgia. CONCLUSION: Although there was marked overlap between the arthritis patient groups, MRI determined bone marrow edema and synovial membrane volumes provided additional information about disease activity and may be used as a marker of it. Bone marrow edema appeared with the highest percentage in patients with long duration of RA (> 3 yrs) and is probably secondary to changes in inflammatory activity.

MRI of the arthritic small joints: comparison of extremity MRI (0.2 T) vs high-field MRI (1.5 T).

The aim of this study was to compare the diagnostic capabilities of extremity MRI (E-MRI) with high-field MRI in arthritic small joints, and to evaluate the patients' acceptance and perceptions of the two MR systems. One hundred three patients (group 1 = 28 patients with RA < 3 years, group 2 = 25 patients with reactive and psoriatic arthritis and mixed connective tissue disease, group 3 = 25 patients with rheumatoid arthritis (RA) more than 3 years and group 4 = 25 patients with arthralgia) underwent dedicated E-MRI and high-field MRI of the wrist and finger joints. Coronal short tau inversion recovery and transversal 3D T1-weighted images before and after gadodiamide (Gd) were performed in both cases to outline the volume of the synovial membrane (Vsm) and to evaluate joints with enhancement, effusion, bone edema, and erosions. Investigators blinded to the clinical findings evaluated the images. Patients' compliance and acceptance of E-MRI and high-field MRI were evaluated. The median Vsm obtained on E-MRI did not differ significantly from that obtained on high-field MRI. Vsm = 1 ml (E-MRI) and 1.1 ml (high-field MRI) before Gd and Vsm = 0.1 ml (E-MRI) and 0 ml (high-field MRI) after Gd (Wilcoxon test, p > 0.05). The difference in agreement was 8% for joint enhancement, 2% for joint effusion, 3% for bone edema, and 4% for bone erosions. Of the patients, 64% preferred E-MRI due to more comfortable positioning and less claustrophobia and noise. Extremity MRI of the small arthritic joints is comparable to high-field MRI and more readily accepted than high-field MRI by this patient group.