Gallium 67 scanning in rheumatoid arthritis

Area of Science:

• Nuclear Medicine
• Rheumatology
• Immunology

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint inflammation.
• Accurate assessment of synovial inflammation is crucial for RA management.
• Gallium 67 (67Ga) citrate is a radiopharmaceutical used in imaging.

Purpose of the Study:

• To investigate the utility of 67Ga scintigraphy in evaluating knee joint inflammation in rheumatoid arthritis.
• To determine if 67Ga uptake correlates with clinical and laboratory markers of disease activity.

Main Methods:

• 38 patients with rheumatoid arthritis underwent bilateral knee 67Ga scans.
• Synovial fluid and synovial tissue were analyzed for white blood cell concentration.
• 67Ga accumulation was quantified and correlated with clinical synovitis and cell counts.

Main Results:

• Significantly higher 67Ga accumulation was observed in knees with active synovitis (p < 0.001).
• Elevated synovial white cell concentration was found in active disease.
• A strong correlation existed between white cell concentration and the 67Ga knee/femoral ratio (p < 0.001).
• 67Ga activity was detected in synovial fluid and synovium.

Conclusions:

• 67Ga scintigraphy is a valuable tool for detecting and quantifying inflammation in rheumatoid arthritis knee joints.
• 67Ga uptake reflects the degree of synovial inflammation and correlates with cellularity.