Dynamic ultrasonography helps diagnose calcium pyrophosphate deposition disease

This case report details an 80-year-old woman with a 6-year history of recurrent swelling and pain in her right knee, compounded by underlying conditions such as hyperuricemia, type 2 diabetes, and chronic renal insufficiency. Diagnostic imaging, including X-ray and ultrasound, revealed a double contour (DC) sign and linear calcifications within the cartilage. Dynamic ultrasound assessment identified high signal shadows, suggesting calcium pyrophosphate deposition (CPPD). Despite the absence of monosodium urate (MSU) deposits confirmed by dual-energy computed tomography and synovial fluid analysis, the presence of calcium pyrophosphate crystals was noted. The report emphasizes the effectiveness of dynamic ultrasonography in distinguishing CPPD from gout.