New Developments in Imaging in Crystalline Arthritis.

Crystalline arthropathies are among the most frequently encountered conditions in medicine. Joint aspiration and microscopy used to be the diagnostic gold standard, but recent recommendations mention that this may not be necessary if typical findings are seen on imaging. Ultrasound, dual-energy computed tomographic (CT) scan, and conventional radiography are recommended in the assessment of gout, calcium pyrophosphate crystal deposition disease, and basic calcium phosphate-related disease. Ultrasound can identify the tophus and its associated tissues that participate in the inflammatory response, and dual-energy CT can find tophaceous material in regions that are difficult to access by physical examination or ultrasound.