Polarized microscopy of synovial fluid to identify uric acid crystals was shown to high utility and reliability in a study of 5 rheumatologists (4 consultants, 1 registrar). 50 SF samples - good agreement w/ κ = 0.71 for MSU, 0.88 for CPP https://t.co/5c7N7spc0t https://t.co/9wXsHuCY6D