Is ultrasound changing the way we understand rheumatology? Including ultrasound examination in the classification criteria of polymyalgia rheumatica and gout.

Ultrasonography (US) is widely used in the diagnosis of rheumatic conditions, and its value for the classification criteria of rheumatic diseases has been recently suggested. According to the EULAR/ACR provisional criteria for polymyalgia rheumatica, adding US to the clinical and serological features will significantly improve the sensitivity of proposed criteria. The ability of high resolution US to detect crystalline deposits of monosodium urate in joints and soft tissues is well recognized. For the first time, the new 2014 ACR/EULAR set of proposed criteria for gout includes advanced imaging techniques for the detection of disease: US and dual-energy computed tomography. Due to low costs and affordability, use of US evaluation for patients with suspected gout will increase both specificity and sensibility of classification criteria. The recent inclusion of US in the classification criteria of various rheumatic diseases, such as PMR and gout, implies that this imaging technique is not only useful as a valued diagnostic tool for individual cases, but also on a larger scale, it will improve doctors' ability to classify diseases. Its use is thus changing our understanding of rheumatic diseases allowing further advances in research and clinical practice.