Abstract

Crystal deposits in and around the joints are common and most often encountered as incidental imaging findings in asymptomatic patients.

However, they can also cause chronic or acute arthropathy, generating symptoms.

In the chronic setting, imaging features are usually characteristic and allow the differentiation of the type of crystal arthropathy. In the acute phase and in the early stages of the crystal deposition, the signs are often non-specific, and the final diagnosis still relies on the analysis of synovial fluid.

Radiography is the main imaging modality for the workup of these conditions. It can confirm the diagnosis and often characterizes the type of crystal arthropathy. In recent years, US has played an increasingly important role in this setting, and is a useful tool in superficially located crystal-induced arthropathies. CT nicely complements radiography for deeper sites, especially the axial skeleton. DECT is a promising tool for the characterization of crystal arthropathies, in particular gout as it permits a quantitative assessment of deposits, and may help in the follow up of patients.

When performed in the acute stage, MRI may show severe inflammatory changes that could be misleading and correlation to radiographs or CT should help to distinguish crystal arthropathies from infectious or tumoral conditions.