Objective

To compare the characteristics of monosodium urate (MSU) crystal deposition at specific anatomical sites of the foot detected by dual-energy computed tomography in patients with different stages of gout.

Materials and methods

This study included 101 patients with gout, 64 had early gout (<3 years) and 37 had late gout (>3 years). We retrospectively compared the total volumes of MSU crystals, the detection rates, and the morphology of MSU crystals at specific anatomical sites in the foot of the patients with different gout durations.

Results

The total volume of MSU crystals in patients with early gout was significantly smaller than that in patients with late gout (P < 0.05). The detection rates and morphology of MSU crystals in the anterior calf tendons, ankle joints, tarsometatarsal joints, and metatarsophalangeal joints differed significantly between the patients with early and late gout (P < 0.05). There were no significant differences in the detection rates of submillimeter MSU crystals at the other specific anatomical sites, except for the tendons of the anterior calf, the ankle joint, and the metatarsal joint (P > 0.05). The submillimeter MSU crystal deposition was most common in the tendons of the posterior calf, the proportions in patients with early gout and late gout were 85.9% and 70.3%. Only submillimeter deposition existed in 52 patients (81.3%) with early gout and 11 patients (29.7%) with late gout at all sites of the foot.

Conclusion

Dual-energy computed tomography detection of submillimeter MSU crystal deposits in the foot is of great significance for the diagnosis of gout, especially along tendons.