Musculoskeletal ultrasound as a diagnostic and prognostic tool in rheumatoid arthritis.

The use of musculoskeletal ultrasound (MSKUS) has increased in a variety of rheumatic conditions, particularly rheumatoid arthritis (RA). MSKUS complements the physical examination by allowing for superior visualization of synovitis and erosive changes compared to conventional radiography and provides detail comparable or supplementary to magnetic resonance imaging (MRI). This modality is also less expensive than MRI and CT scans, without claustrophobia or other contraindications, while uniquely providing dynamic, rather than static imaging. A growing body of literature for MSKUS in RA is contributing significantly to the understanding of diagnostic and prognostic utility, longitudinal assessment, and disease remission. Furthermore, scoring systems focusing on the patient level rather than individual joints have been developed, allowing for simplification of exams while still retaining accuracy and utility. The combination of these advances has led to increased use of MSKUS in RA in the realm of research as well as at the bedside and in the clinic.