Plain radiography images demonstrating bone erosions. (a) Radiography of the hand in an oblique projection demonstrating bone erosions located in metacarpal phalangeal joints and in proximal and distal interphalangeal joints. (b) Radiography of the foot in a dorsal–plantar projection showing extensive bone erosions involving the first and fifth metatarsal phalangeal joints, and proximal and distal interphalangeal joints. Typical intratophus calcifications may be seen in intraosseous tophi and in periarticular tophi. (c) Radiography of the tarsal bones in an oblique projection showing erosions in the scaphoid and first metatarsal bone, with typical overhanging edges. Soft-tissue masses due to extensive tophaceous deposition may also be observed.