Intratendinous Power Doppler Changes Related to Patient Position in Seronegative Spondyloarthritis

Abstract

Seronegative spondyloarthropathy (SpA) is a chronic inflammatory disease that includes a heterogeneous group of diseases such as psoriatic arthritis (PsA), ankylosing spondylitis (AS), reactive arthritis, arthritis associated with inflammatory bowel disease, and undifferentiated SpA. Enthesis and tendon involvement are 2 important aspects of SpA1. There is strong evidence that demonstrates the role of ultrasound (US) with power Doppler (PD) technique and its higher sensitivity, compared to the clinical examination, in the detection of signs of entheseal involvement in both late and early stages2. One of its main limits is operator dependency. A minimal change in the transducer position or an erroneous setting can provide completely different information, easily leading to misinterpretations. The importance of the patient’s position during the US assessment has not been well studied3,4. We investigated the effect of this phenomenon at different enthesis levels in 4 patients with SpA. US images were obtained with a MyLab 70 XVG US system (Esaote Biomedica, Genoa, Italy) with a 6–18 MHz linear transducer B-mode frequency of 18 MHz and a Doppler frequency of 9.1 …