Dr. Amorese-O’Connell is a rheumatology fellow and Dr. Reginato is the fellowship program director and associate professor of medicine, both in the Division of Rheumatology at The Warren Alpert School of Medicine at Brown University in Providence, Rhode Island. Dr. Reginato is also the acting chief in the Division of Rheumatology at the Providence VAMC in Rhode Island. Dr. Gutierrez is an associate professor of rheumatology at the Clinica Rheumatologica, Universita Politecnica delle Marche in Jesi, Ancona, Italy, and chair, Research Direction of the Instituto Nacional de Rehabilitacion, Mexico City, Mexico.
References
Another application of US is in the evaluation of subclinical inflammation at the enthesis in patients with a history of psoriasis without prior history of PsA. 27,31 In those patients with psoriatic nail changes, more subclinical enthesitis was found compared with patients with psoriasis without nail involvement. 32 Furthermore, subclinical joint inflammation has also been described. 33 These findings suggest a possible predictive value in patients with psoriasis who should be monitored on a regular basis, because they are at risk of developing PsA.
Subclinical enthesitis by US imaging has been described in patients with recurrent anterior uveitis and inflammatory bowel disease. 34,35 In cases where SpA is suspected but diagnostic criteria are not fulfilled, the presence of one enthesis with increased PD signal highly predicts the eventual development of SpA. 36 Therefore, B-mode and PD evaluations of the entheses are critical in the identification of patients who are at an increased risk of developing SpA. 37 Treatment monitoring is performed by using a US scoring system in a follow-up evaluation of patients with PsA. Some of the scoring systems have evaluated changes in B-mode US lesions (enthesis and soft tissues, such as skin and nails), whereas others focus on changes in the PD signal. 37,38
The Five Targets Power Doppler for Psoriatic Disease PD scoring system comprises the assessment of PD signal in the joint, tendon with synovial sheath, enthesis, skin, and nails. Each of the targets is scored from 0 to 3 points, with a maximum of 15 total points. Some studies have shown that PDUS can provide valuable information in the evaluation of psoriatic plaques and onychopathy in patients with psoriasis and PsA. 39 The detection of a PD signal within the dermis and nail bed is equivalent to active inflammation in these sites. 39-41 However, further studies with larger cohorts proving inter- and intra-observer reliability are necessary to consolidate these findings and comfortably apply them in clinical practice.
Osteoarthritis
Increasingly US is studied for its validity and reliability in evaluating periarticular soft tissue and cartilage changes in knee OA. The associated US findings include a high prevalence of synovitis with a low prevalence of a PD signal, the presence of osteophytes, and joint space narrowing. 42,43 Increased PD signal, synovial hypertrophy, and joint effusion were observed in patients with radiographically erosive OA compared with those with radiographically nonerosive OA. 44
Bone erosions and inflammatory changes are also frequently detected by US in both erosive and nodal hand OA. 45 Compared with MRI, US has shown a good to excellent correlation in the assessment of osteophytes, bone erosions, synovitis, and tenosynovitis in erosive and hand nodal OA. 46 In comparison with CR, US has shown to have a higher sensitivity in the assessment of bony erosions, osteophytes, and space narrowing. 47 Ultrasound is able to detect changes in the earlier stages of cartilage erosion in OA, characterized by loss of the sharp contour and variations in the echogenicity of the cartilage matrix, asymmetric shrinkage, and ultimately the disappearance of the cartilaginous band, which is more evident in the later stages of OA. 45
