Objective. To investigate the validity, reproducibility, and responsiveness of a simplified power Doppler ultrasound (PDUS) assessment of joint inflammation compared with a comprehensive 44-joint PDUS assessment in patients with rheumatoid arthritis (RA) who started therapy with a biologic agent. Methods. A total of 160 patients with active RA who started a biologic agent were prospectively recruited in 18 Spanish centers. The patients underwent clinical and laboratory assessment and blinded PDUS examination at baseline and 6 months. A PDUS examination of 128 synovial sites in 44 joints was performed. US synovitis and PD signal were semiquantitatively graded from 1 to 3 in all synovial sites. US count and index for synovitis and PD signal were obtained. PDUS intraobserver and interobserver reliability were evaluated. A process of data reduction based on the frequency of involvement of synovial sites by both synovitis and PD signal was conducted. Construct and discriminant validity of a simplified PDUS assessment was investigated. Results. A PDUS simplified assessment including 24 synovial sites from 12 joints detected 100% of patients with synovitis and 91% of patients with PD signal. There was a highly significant correlation between the 44-joint count and index for synovitis and PD signal and the 12-joint count and index for synovitis and PD signal at baseline and 6 months (r ‫؍‬ 0.84 -0.90, P < 0.0005). The smallest detectable difference was lower than the mean change in simplified PDUS variables. Conclusion. A 12-joint PDUS assessment of RA joint inflammation may be a valid, feasible method for multicenter monitoring of therapeutic response to biologic agents.

Objective: To assess the multiexaminer reproducibility and the accuracy comparing with cadaver anatomic specimens of ultrasound (US) measurement of femoral articular cartilage (FAC) thickness. Methods: In 8 flexed cadaver knees, FAC thickness was blindly, independently and consecutively measured twice by 10 rheumatologists at the lateral condyle (LC), medial condyle (MC) and intercondylar notch (IN) with US. After the US measurements, the knees were dissected. Articular cartilage integrity was evaluated macroscopically in the femoral condyles. FAC thickness was blindly measured in the specimens using a stereoscopic magnifying loupe and a digitised image software. Interexaminer and intraexaminer reliability of US FAC thickness measurement and agreement between US and anatomic measurements were assessed by estimating the intraclass correlation coefficient (ICC). Conclusion: US demonstrated a good reproducibility in FAC thickness measurement by multiple examiners. In addition, US FAC thickness measurement was accurate in normal to moderately damaged cartilage.

Psoriatic patients showed a significant prevalence of asymptomatic US synovitis and enthesopathy, which may indicate a subclinical musculoskeletal involvement.

Objective: To assess the interobserver reliability of the main periarticular and intra-articular ultrasonographic pathologies and to establish the principal disagreements on scanning technique and diagnostic criteria between a group of experts in musculoskeletal ultrasonography. Methods: The shoulder, wrist/hand, ankle/foot, or knee of 24 patients with rheumatic diseases were evaluated by 23 musculoskeletal ultrasound experts from different European countries randomly assigned to six groups. The participants did not reach consensus on scanning method or diagnostic criteria before the investigation. They were unaware of the patients' clinical and imaging data. The experts from each group undertook a blinded ultrasound examination of the four anatomical regions. The ultrasound investigation included the presence/absence of joint effusion/synovitis, bony cortex abnormalities, tenosynovitis, tendon lesions, bursitis, and power Doppler signal. Afterwards they compared the ultrasound findings and re-examined the patients together while discussing their results. Results: Overall agreements were 91% for joint effusion/synovitis and tendon lesions, 87% for cortical abnormalities, 84% for tenosynovitis, 83.5% for bursitis, and 83% for power Doppler signal; k values were good for the wrist/hand and knee (0.61 and 0.60) and fair for the shoulder and ankle/foot (0.50 and 0.54). The principal differences in scanning method and diagnostic criteria between experts were related to dynamic examination, definition of tendon lesions, and pathological v physiological fluid within joints, tendon sheaths, and bursae. Conclusions: Musculoskeletal ultrasound has a moderate to good interobserver reliability. Further consensus on standardisation of scanning technique and diagnostic criteria is necessary to improve musculoskeletal ultrasonography reproducibility.

This review addresses the use of ultrasound (US) as an imaging technique for the evaluation and monitoring of the osteoarthritic joint. US complements both the clinical examination and radiological imaging by allowing the rheumatologist to recognize not only the bony profile but also to visualize the soft tissues. Systematic US scanning following established guidelines can demonstrate even minimal abnormalities of articular cartilage, bony cortex and synovial tissue. US is also extremely sensitive in the detection of soft tissue changes in the involved joints including the proliferation of the synovium and changes in the amount of fluid present within the joint. Monitoring the amount of fluid in the hip and knee joint with osteoarthritis may be a potentially useful finding in the selection of patients for clinical investigation and for assessing their response to therapeutic interventions.