Ultrasonography in the assessment of calcium pyrophosphate deposition disease

Calcium pyrophosphate deposition (CPPD) disease is an arthropathy with increasing prevalence in the aging population that is associated with significant musculoskeletal morbidity. Although synovial fluid analysis (SFA) has been considered the gold standard for diagnosis, imaging is gaining an increasing role in the diagnosis and assessment of CPPD disease. Ultrasound (US) has proven to be useful in identifying calcium crystals while simultaneously assessing the surrounding inflammatory and structural damage consequent to calcific tissue deposition. Point-of-care ultrasound has the additional benefit of focusing the US evaluation to targeted symptomatic structures at the bedside, as well as allowing the sonographer to additionally scan joints frequently affected in CPPD disease to enhance the diagnostic utility of US. Furthermore, diagnostic and therapeutic procedures under US guidance can increase the yield of a diagnostic aspiration in CPPD disease and provide a therapeutic role in facilitating accurate delivery of medication in difficult to reach structures. Understanding the utility and limitations of US is essential to optimize the benefits of this imaging modality in the evaluation of CPPD disease.