Doppler ultrasonography for assessing rheumatoid arthritis Review

Doppler ultrasound is able to visualize blood flow by the change in frequency (Doppler shift) of sound waves that are reflected by moving blood cells inside the vessels (Doppler effect). Since hyperemia caused by vasodilation and angiogenesis can be the earliest detectable pathologic changes in the beginning of synovitis, Doppler ultrasonography can be used to assess inflammatory activity. In addition, several studies demonstrate a strong correlation between MRI as well as histological findings (blood vessel density) and Doppler sonographic visualization of synovial perfusion. To achieve this goal, equipment settings must be adapted to slow blood flow in very small blood vessels to reach an appropriate imaging quality. Color and power Doppler ultrasound depict different grades of intra-articular and peritendineous blood flow, which allows an estimation of inflammatory activity and is a helpful tool for the monitoring of rheumatic diseases during follow-up.