Power Doppler signal at the enthesis and bone erosions are the most discriminative OMERACT ultrasound lesions for SpA: results from the DEUS (Defining Enthesitis on Ultrasound in Spondyloarthritis) multicentre study.

OBJECTIVES: To assess, in spondyloarthritis (SpA), the discriminative value of the Outcome Measures in Rheumatology (OMERACT) ultrasound lesions of enthesitis and their associations with clinical features in this population. METHODS: In this multicentre study involving 20 rheumatology centres, clinical and ultrasound examinations of the lower limb large entheses were performed in 413 patients with SpA (axial SpA and psoriatic arthritis) and 282 disease controls (osteoarthritis and fibromyalgia). 'Active enthesitis' was defined as (1) power Doppler (PD) at the enthesis grade ≥1 plus entheseal thickening and/or hypoechoic areas, or (2) PD grade >1 (independent of the presence of entheseal thickening and/or hypoechoic areas). RESULTS: In the univariate analysis, all OMERACT lesions except enthesophytes/calcifications showed a significant association with SpA. PD (OR=8.77, 95% CI 4.40 to 19.20, p<0.001) and bone erosions (OR=4.75, 95% CI 2.43 to 10.10, p<0.001) retained this association in the multivariate analysis. Among the lower limb entheses, only the Achilles tendon was significantly associated with SpA (OR=1.93, 95% CI 1.30 to 2.88, p<0.001) in the multivariate analyses. Active enthesitis showed a significant association with SpA (OR=9.20, 95% CI 4.21 to 23.20, p<0.001), and unlike the individual OMERACT ultrasound lesions it was consistently associated with most clinical measures of SpA disease activity and severity in the regression analyses. CONCLUSIONS: This large multicentre study assessed the value of different ultrasound findings of enthesitis in SpA, identifying the most discriminative ultrasound lesions and entheseal sites for SpA. Ultrasound could differentiate between SpA-related enthesitis and other forms of entheseal pathology (ie, mechanical enthesitis), thus improving the assessment of entheseal involvement in SpA.

Reliability assessment of the definition of ultrasound enthesitis in SpA: results of a large, multicentre, international, web-based study.

OBJECTIVES: To investigate the reliability of the OMERACT US Task Force definition of US enthesitis in SpA. METHODS: In this web exercise, based on the evaluation of 101 images and 39 clips of the main entheses of the lower limbs, the elementary components included in the OMERACT definition of US enthesitis in SpA (hypoechoic areas, entheseal thickening, power Doppler signal at the enthesis, enthesophytes/calcifications, bone erosions) were assessed by 47 rheumatologists from 37 rheumatology centres in 15 countries. Inter- and intra-observer reliability of the US components of enthesitis was calculated using Light's kappa, Cohen's kappa, Prevalence And Bias Adjusted Kappa (PABAK) and their 95% CIs. RESULTS: Bone erosions and power Doppler signal at the enthesis showed the highest overall inter-reliability [Light's kappa: 0.77 (0.76-0.78), 0.72 (0.71-0.73), respectively; PABAK: 0.86 (0.86-0.87), 0.73 (0.73-0.74), respectively], followed by enthesophytes/calcifications [Light's kappa: 0.65 (0.64-0.65), PABAK: 0.67 (0.67-0.68)]. This was moderate for entheseal thickening [Light's kappa: 0.41 (0.41-0.42), PABAK: 0.41 (0.40-0.42)], and fair for hypoechoic areas [Light's kappa: 0.37 (0.36-0.38); PABAK: 0.37 (0.37-0.38)]. A similar trend was observed in the intra-reliability exercise, although this was characterized by an overall higher degree of reliability for all US elementary components compared with the inter-observer evaluation. CONCLUSIONS: The results of this multicentre, international, web-based study show a good reliability of the OMERACT US definition of bone erosions, power Doppler signal at the enthesis and enthesophytes/calcifications. The low reliability of entheseal thickening and hypoechoic areas raises questions about the opportunity to revise the definition of these two major components for the US diagnosis of enthesitis.

Bone erosions in rheumatoid arthritis: ultrasound findings in the early stage of the disease.

OBJECTIVE: The objective of this study was to determine the prevalence and distribution of bone erosions detectable by US in patients with early RA (ERA) in comparison with long-standing RA (LSRA), other erosive diseases and healthy controls. METHODS: Thirty patients with ERA and 80 patients with LSRA were consecutively recruited. Thirty patients with PsA, 15 with primary OA, 10 with gout and 20 healthy subjects were included as controls. Bone erosions were investigated at the following anatomical sites: the second and fifth metacarpal heads, the ulnar head and the first and fifth metatarsal heads, bilaterally. Dorsal, volar and lateral aspects were explored on longitudinal and transverse views. RESULTS: At least one US bone erosion was found in 20 (66.7%) of 30 patients with ERA and in 10 (33%) of them it was found on the fifth metatarsal head. Bone erosions were most frequently found on the lateral quadrants of all scanned anatomical sites. If the second and fifth metacarpal heads and the fifth metatarsal head were scanned, an erosive disease could be found in 60% of ERA patients. The first metatarsal head was most frequently involved in the disease control group. CONCLUSION: This study found a high percentage of ERA patients with US bone erosions, with the fifth metatarsal head and the lateral aspects the most frequently involved site and quadrants. US scanning for bone erosions on a few target joints was found feasible and provided information not obtainable with clinical examination.

Ultrasound detection of cartilage calcification at knee level in calcium pyrophosphate deposition disease.

OBJECTIVE: To determine the sensitivity, specificity, and accuracy of ultrasound (US) in the detection of cartilage calcification at knee level in patients with calcium pyrophosphate deposition disease (CPDD) and to assess the interobserver reliability. METHODS: Seventy-four CPDD patients and 83 controls with other chronic arthritis were included. All patients underwent a clinical examination, synovial fluid analysis, and radiographic assessment of the knee. US examinations were performed in order to detect hyperechoic spots within the hyaline cartilage layer and hyperechoic areas within the meniscal fibrocartilage. Twenty patients were assessed by 2 operators in order to calculate the interobserver reliability. RESULTS: A total of 314 knees in 157 patients (74 with CPDD, 19 with rheumatoid arthritis, 17 with spondyloarthritis, 32 with osteoarthritis, and 15 with gout) were assessed. In the 74 patients with CPDD, hyaline cartilage spots were detected by US in at least 1 knee in 44 patients (59.5%), whereas radiography detected hyaline cartilage spots in 34 patients (45.9%) (P < 0.001). Meniscal fibrocartilage calcifications were detected by US in 67 of the 74 CPDD patients (90.5%), whereas conventional radiography detected calcifications in 62 patients (83.7%) (P = 0.011). The criterion validity expressed as percentage of sensitivity, specificity, and accuracy of US in the detection of articular cartilage calcification was high. Both kappa values and overall agreement percentages showed moderate to excellent agreement. CONCLUSION: US is an accurate and reliable imaging technique in the detection of articular cartilage calcification at knee level in patients with CPDD.

Ultrasound imaging for the rheumatologist XLV. Ultrasound of the shoulder in psoriatic arthritis.

OBJECTIVES: The aims of this study were to investigate the prevalence of ultrasound (US) pathologic abnormalities in the shoulders of psoriatic arthritis (PsA) patients and to compare them with the main clinical findings. METHODS: Ninety-seven PsA patients were enrolled in the study. The subacromial/subdeltoid bursa, the sheath of the long biceps tendon, the glenohumeral joint and the acromion-clavicular joint were examined for the presence of synovial effusions and synovial hypertrophy. Rotator cuff tendons (supraspinatus, subscapularis, infraspinatus) were imaged for tendinosis, calcifications and total or partial tears, while deltoid enthesis were evaluated for local enthesitis and the lesser and greater tuberosity of the humerus for the presence of enthesophytes. RESULTS: Tendinosis represented the most frequent abnormal finding. Supraspinatus tendinosis was detected more often than subscapularis and infraspinatus tendinosis. When considering tendon tear, supraspinatus was also the most frequently involved anatomical structure. Clinical examination frequently failed to detect abnormalities in patients in whom US examination showed pathological findings. This is particularly true for tendon involvement, i.e. effusion within the sheath of the biceps tendon was imaged in 43 shoulders but clinical assessment reported abnormalities only in 22 shoulders (p<0.0001). CONCLUSIONS: US examination appears to be a useful and sensitive imaging technique, specifically in identifying joint and tendon involvement of the shoulder.

Development of a preliminary US power Doppler composite score for monitoring treatment in PsA.

OBJECTIVE: To develop a preliminary power Doppler (PD) US composite score for global assessment of PsA patients. METHODS: Sixteen PsA patients receiving anti-TNF-α therapy were enrolled. All patients were involved in multiple psoriatic targets, including joints, tendon, enthesis, skin and nail. The target with the highest PD signal, one for each target area, was selected to be scanned at baseline and at follow-up visit 8 weeks after. For each target, PD was graded according to semi-quantitative scoring systems. Inter- and intra-observer reliability and feasibility was also investigated. The new PD composite score for PsA was called Five Targets PD for Psoriatic Disease (5TPD). RESULTS: Sixty targets (16 joints, 9 tendons, 11 enthesis, 16 psoriatic plaques and 8 psoriatic onychopathies) were assessed. A significant improvement of the clinical scores was found at follow-up with respect to the baseline: HAQ modified for SpA (HAQ-S) (P = 0.0001); Psoriasis Area and Severity Index (P = 0.0001) and Nail Psoriasis Severity Index (P = 0.35). The 5TPD showed a significant change between baseline and follow-up (P = 0.0001). There was no significant correlation between HAQ-S and 5TPD findings. The inter- and intra-observer κ-values varied from good to excellent at baseline and follow-up. The time spent on baseline US examinations was mean (s.d.) 10.5 (2.0) min and no more than 7 min for follow-up assessment. CONCLUSION: The present study provides a new working hypothesis that the sonographic core set may be useful to construct a PDUS composite score for the assessment of PsA. The 5TPD formula provides a feasible and reliable approach for multi-target monitoring of psoriatic disease.

CS injection of tenosynovitis in patients with chronic inflammatory arthritis: the role of US.

OBJECTIVE: The main aim of this study was to investigate the short-term efficacy of CS loco-regional treatment performed under US guidance in tenosynovitis of patients with chronic inflammatory arthritis. METHODS: Thirty consecutive patients affected by chronic arthritis and with clinical suspicion of tenosynovitis were recruited to undergo US assessment. In the sonographically proven cases, US-guided CS injection was performed. A visual analogue scale for pain (ranging from 0 to 10) and a tenderness score (ranging from 0 to 3) were used for the clinical evaluation. Sonographic pathological findings indicative of tenosynovitis were scored using a semi-quantitative 4-grade scoring system, for both grey-scale and power Doppler US, at baseline and during a follow-up visit at 2 weeks after the CS injection. RESULTS: In 21 (70%) of 30 patients, the clinical suspicion of tenosynovitis was confirmed (9 with RA, 11 with PsA and 1 with ReA). In the other nine patients, US revealed synovitis of the adjacent joints, bursitis, oedema of the s.c. tissue or a partial tear. In all cases the appropriate needle placement and subsequent CS injection into the tendon sheath were obtained with US confirmation. A significant reduction in all clinical and sonographic scorings was found during the follow-up visit. CONCLUSIONS: The present study shows the efficacy of US-guided peritendinous CS injections in the management of patients with chronic inflammatory arthritis presenting as US-proven tenosynovitis.

Multi-examiner reliability of automated radio frequency-based ultrasound measurements of common carotid intima-media thickness in rheumatoid arthritis.

OBJECTIVES: To assess the reliability of the automated radio frequency (RF)-based US measurement of carotid intima-media thickness (IMT) performed by rheumatologists and to evaluate the variability between this method and the conventional B-mode US measurement of carotid IMT in RA patients. METHODS: Twelve rheumatologists measured in two blinded rounds the IMT of both common carotid arteries (CCAs) of seven RA patients with an automated RF-based method. At each round, a cardiologist measured both CCA-IMTs of the patients using an automated B-mode method. Inter-observer reliability for RF-based IMT measurements was evaluated by the intra-class correlation coefficient (ICC). Intra-observer reliability for RF-based IMT measurements was assessed using the root mean square coefficient of variation (RMS-CV), Bland-Altman method and ICC. Agreement between the two US methods was evaluated by the Bland-Altman method, ICC and RMS-CV. RESULTS: Inter-observer ICCs for the RF-based CCA-IMT measurements were 0.85 (95% CI 0.69, 0.94) for the first round, and 0.77 (95% CI 0.55, 0.91) for the second round. RMS-CVs for the RF-based CCA-IMT measurements varied from 5.6 to 11.7%. The mean intra-observer ICC for the RF-based CCA-IMT measurements was 0.61 (95% CI 0.46, 0.71). In the Bland-Altman analysis for agreement between RF-based and B-mode CCA-IMT measurements, the mean difference varied from -0.6 to -19.7 µm. Inter-method ICCs varied from 0.57 to 0.83 for 11 rheumatologists. Inter-method RMS-CVs varied from 11.3 to 13.7%. CONCLUSIONS: Our results suggest that automated RF-based CCA-IMT measurement performed by rheumatologists can be a reliable method for assessing cardiovascular risk in RA patients.

Differential diagnosis between rheumatoid arthritis and psoriatic arthritis: the value of ultrasound findings at metacarpophalangeal joints level.

OBJECTIVE: To investigate the potential of ultrasound (US) in the differential diagnosis between rheumatoid arthritis (RA) and psoriatic arthritis (PsA) at metacarpophalangeal (MCP) joints level. METHODS: 18 RA patients and 20 PsA patients with clinical involvement of MCP joints were included. All US examinations were performed by two rheumatologists investigating: presence of joint cavity widening (JCW), synovial fluid and/or synovial hypertrophy, peritenon extensor tendon inflammation (PTI) and intra-articular or peri-tendinous power Doppler (PD) signal. RESULTS: A total of 83 MCP joints in 18 RA patients were assessed. In all of these the authors found different degrees of JCW. 15 of 83 (18%) MCP joints showed synovial fluid, whereas 68 of 83 (82%) MCP joints showed synovial hypertrophy. In 72 of 83 (86.7%) MCP joints intra-articular PD was detected. No PTI pattern was found in these patients. In PsA patients, a total of 82 MCP joints in 20 patients were assessed. 54 of 82 (65.8%) MCP joints showed PTI pattern (p = 0.001). In 50 of these 54 (92.5%) MCP joints extra-articular PD signal was detected (p = 0.001). 28 of 82 (34.1%) MCP joints showed different degrees of JCW. 6 of 28 (21.4%) MCP joints presented synovial fluid, whereas 22 of 28 (78.5%) MCP joints showed synovial hypertrophy. In 8 of 82 (9.7%) MCP joints the JCW and PTI patterns were found contemporaneously. CONCLUSIONS: Preliminary results demonstrate that PTI pattern is a higher characteristic of PsA, which suggests a potential role of US in the differential diagnosis between RA and PsA at MCP joints level.

Interobserver reliability of ultrasonography in the assessment of cartilage damage in rheumatoid arthritis.

OBJECTIVES: To evaluate the interobserver reliability of ultrasonography (US) in the assessment of cartilage damage at metacarpophalangeal (MCP) joint level in patients with rheumatoid arthritis (RA). METHODS: US examinations were performed on 80 MCP joints of 20 patients with RA using a MyLab70 XVG (Esaote Biomedica, Genoa, Italy), equipped with a broadband linear probe (6-18 MHz). For each patient, second and third MCP joints of both hands were examined independently on the same day by two rheumatologists (an experienced musculoskeletal sonographer and an investigator with limited US training). A multiplanar scanning technique on dorsal, lateral and volar aspects of the MCP joints was adopted. All US pathological findings were documented on at least two perpendicular scanning planes. Each joint was assessed by quadrant for the presence or absence of cartilage damage. Cartilage damage was also scored per quadrant on a five-grade semiquantitative scoring system on which investigators reached a consensus prior to the study. RESULTS: Exact agreement between investigators was found in 173 out of 200 quadrants (86.5%) with regard to presence or absence of cartilage damage. Percentages of exact agreement for cartilage damage semiquantitative assessment at dorsal, lateral and volar quadrants were 72.5%, 52.5% and 85%, respectively, while unweighted κ values were 0.561, 0.366 and 0.766, respectively. CONCLUSIONS: The present study demonstrated moderate to good interobserver reproducibility of a semiquantitative scoring system based on qualitative morphological changes for cartilage damage at MCP joint level in patients with RA.