Gout of ankle and foot: DECT versus US for crystal detection

To compare dual-energy computed tomography (DECT) and ultrasound (US) in detecting monosodium urate (MSU) crystals in the ankle and foot in patients with acute gouty arthritis.

Bilateral ankle and foot were examined by DECT and US and the differences between the findings were compared.

A total of 50 patients underwent DECT and US examinations. At the patient level, the overall positivity of crystal deposition detected by DECT was higher than that by US (92% vs 68%, P = 0.005). The agreement of detecting crystal deposition between DECT and US was not very strong (К = 0.44, P = 0.003). At different joint/area levels, there were significant differences between the two examinations in the area of the dorsum (36% vs 12%, P = 0.009) and metatarsal bone (34% vs 12%, P = 0.017), but the sensitivity of DECT and US was similar in the first metatarsophalangeal joint (MTP) and ankle areas (P>0.05). Agreement between the two examinations in the ankle and first MTP was very strong (К = 0.86, P < 0.001; К = 0.79, P < 0.001, respectively). However, agreement between the two examinations in other joints/areas was poor.

These findings indicated that DECT should be the first choice for acute gouty arthritis in patients with ankle and foot involvement. Key Points • There is little data regarding DECT and US in detecting MSU crystals in the ankle and foot in patients with acute gouty arthritis. • The overall positivity of crystal deposition detected by DECT was higher than that by US, but the sensitivity of DECT and US was similar in the first metatarsophalangeal joint (MTP) and ankle areas. • Agreement between the two examinations in the ankle and first MTP was very strong; however, agreement between the two examinations in other joints/areas was poor.