Fig. 2

Patient 14. Erosion of distal right metatarsal head, imaged by radiograph (panel (a), arrow), ultrasound (panel (b), arrow), CT (panel (c), arrow) and DECT (panel (d), arrow). Fluffy, hyperechoic material is evident in the synovial space on ultrasound (panel (b), arrow). Note the absence of any green pixellated areas (MSU deposits) in panel (d). The DECT scan was positive for MSU deposits in the left distal metatarsal head (not shown)