Figure 2
A 56 years old male with acute pain of left foot and ankle joint, serum uric acid 517.6 μmol/L. On the gray scale image (A), a tophus (arrow) can be seen in the achilles tendon area behind calcaneus. On the uric acid (hydroxyapatite) map (B), the tophus was stained red with the threshold of 1342 mg/cm3.
