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.

'Double target' ultrasound monitoring of biologic therapy in psoriatic arthritis.

OBJECTIVES: We aimed to 1) evaluate by power Doppler (PD) ultrasound (US) the response to therapy of the most inflamed joint and enthesis (target sites) in psoriatic arthritis (PsA) patients starting a biologic disease-modifying anti-rheumatic drug (bDMARD); and 2) to investigate the correlation between the US response and clinical data. METHODS: Consecutive PsA patients with US synovitis and US 'active' enthesitis, starting a bDMARD, were included. The joint with the highest OMERACT-EULAR-US composite score and the enthesis with the highest PD grade (targets) were identified at baseline. The US examination and clinical assessment were performed at 0, 3 and 6 months. The response of OMERACT-EULAR-US synovitis composite score was defined as reaching a grade = 0 at follow-up examination; synovial and entheseal PD responses were defined as a PD=0 and/or a reduction of ≥2 PD grades at follow-up examination. RESULTS: Thirty patients were included. Synovitis composite score, synovial PD and entheseal PD showed significant responses at 3 and 6 months compared to baseline (p<0.01). Synovial PD responses were higher than entheseal PD responses at 3 months (71.4% vs 40.0%, p=0.01) and 6 months (77.8% vs. 46.7%, p=0.02). US synovitis responses were correlated with DAPSA (p<0.01) and MDA responses (p=0.01 for composite score, p=0.02 for PD). CONCLUSIONS: US was found sensitive for monitoring treatment response in PsA patients starting a biologic drug. Entheseal PD was less responsive than synovial PD, suggesting that enthesitis may represent a 'difficult-to-treat' domain in PsA.

Diagnosis of calcium pyrophosphate crystal deposition disease by ultrasonography: how many and which sites should be scanned?

OBJECTIVE: To develop the optimal US scanning protocol for the diagnosis of CPPD disease. METHODS: In this cross-sectional study, consecutive patients with a crystal-proven diagnosis of CPPD disease, and age-, sex-matched disease controls and with a negative synovial fluid analysis were prospectively enrolled in two Italian Institutions. Four rheumatologists, blinded to patients' clinical details, performed US examinations using a standardised scanning protocol including 20 joints (shoulders, elbows, wrists, metacarpophalangeal joints from 2nd to 5th fingers, hips, knees, ankles). CPPD was identified as presence/absence, according to the OMERACT definitions. Reduced US scanning protocols were developed by selecting the most informative joints to be imaged by US using the LASSO technique. Patients were randomly divided into training and validation sets. Their diagnostic accuracy was tested comparing the area under the ROC curves. RESULTS: 204 participants were enrolled: 102 with CPPD disease and 102 disease controls [age (mean±standard deviation) 71.3 ± 12.0 vs 71.1 ± 13.5 years, female: 62.8% vs 57.8%].The median number of joints with US evidence of CPPD was 5 (IQR: 4-7) and 0 (IQR: 0-1) in patients with CPPD disease and controls, respectively (p< 0 01).The detection of CPPD in ≥ 2 joints using a reduced scanning protocol (bilateral assessment of knees, wrists, and hips) showed a sensitivity of 96.7% (95%CI: 82.8-99.9) and a specificity of 100 (95%CI: 88.8-100.0) for the diagnosis of CPPD disease and had good feasibility [(mean±standard deviation) 12.5 ± 5.3 min]. CONCLUSION: Bilateral US assessment of knees, wrists, and hips had excellent accuracy and good feasibility for the diagnosis of CPPD disease.

Multimodal ultrasound muscle assessment in patients with rheumatic diseases: a patient-based reliability study.

Objectives: The aim was to explore the inter-reliability of a newly developed US scanning protocol (multimodal US) for the assessment of different aspects of sarcopenia-related muscle involvement, including muscle mass, muscle quality and muscle stiffness [using point shear-wave elastography (SWE)], in patients with rheumatic and musculoskeletal diseases (RMDs). Methods: Quadriceps muscle mass (i.e. muscle thickness), muscle quality (i.e. muscle echogenicity evaluated with both a visual semi-quantitative scale and a dedicated software package for image analysis, ImageJ) and point SWE measurements were obtained by two rheumatologists (blinded to each other's evaluation) in consecutive RMD patients without previous/current myositis or neuromuscular disorders.Inter-reliability was assessed using the intraclass correlation coefficient (ICC) for continuous variables and Cohen's kappa (κ) for categorical variables. Results: A total of 45 RMD patients were enrolled [mean age 54.5 (16.0) years, male-to-female ratio 1:1.5, mean BMI 24.6 (4.6) kg/m2], 10 with PsA, 7 RA, 5 AS, 5 PMR, 4 SLE, 4 gout, 4 OA, 3 FM and 3 SSc. The grade of inter-rater reliability was excellent for muscle mass [ICC = 0.969 (0.953 < ICC < 0.979)]. Regarding muscle echogenicity, the agreement was substantial/almost perfect using the visual semi-quantitative scale (weighted linear = 0.793, weighted squared = 0.878) and excellent using ImageJ analysis [ICC = 0.916 (0.876 < ICC < 0.944)]. Finally, a good agreement was obtained for point SWE measurements [ICC = 0.76 (0.712 < ICC < 0.8)]. Conclusion: Multimodal US is a novel and reliable tool for the evaluation of different aspects of muscle involvement (muscle mass, muscle quality and muscle stiffness) in RMD patients.

Ultrasound in the Management of Patients With Psoriatic Arthritis: Systematic Literature Review and Novel Algorithms for Pragmatic Use.

OBJECTIVE: In 2015, the European Alliance of Associations for Rheumatology (EULAR) published recommendations for the use of imaging for the diagnosis and management of spondyloarthritis (SpA) in clinical practice. These recommendations included the use of ultrasound (US) in patients with psoriatic arthritis (PsA), but the management was not clearly distinguished from that of SpA. We aimed to systematically review the literature on the role of US for the management of PsA, and to propose pragmatic algorithms for its use in clinical practice. METHODS: A group of 10 rheumatologists, experienced in imaging and musculoskeletal US, met with the objectives of formulating key questions for a systematic literature review (SLR), appraising the available evidence, and then proposing algorithms on the application of US in suspected or established PsA, based on both the literature and experts' opinions following a Delphi process. RESULTS: The SLR included 120 articles, most of which focused on the diagnostic process. The elevated number of articles retrieved suggests the interest of rheumatologists in using US in the management of PsA. After a consensual discussion on literature data and expert opinion, the following 3 algorithms were developed to be used in practical situations: suspicion of PsA, management of PsA with good clinical response, and management of PsA with insufficient clinical response. CONCLUSION: The SLR showed interest by rheumatologists in using US to objectively evaluate PsA for diagnosis and management. We propose 3 practical algorithms to guide its use in the clinical management of patients, from diagnosis to the assessment of treatment response. Further studies are needed to define remission and to assess the ability of US to predict disease severity.

Dynamic assessment of the double contour sign by ultrasonography helps to distinguish between gout and calcium pyrophosphate deposition disease.

OBJECTIVE: To test whether the double contour (DC) sign has a different dynamic behaviour in gout and calcium pyrophosphate deposition (CPPD) and whether the dynamic assessment of the DC sign increases its accuracy in gout diagnosis. METHODS: This cross-sectional analysis included patients with gout meeting the 2015 ACR/EULAR classification criteria and patients with crystal-proven diagnosis of CPPD. Hyaline cartilages were explored by ultrasound (US) to detect the DC sign (ie, abnormal hyperechoic band over the superficial margin of hyaline cartilages) and its dynamic behaviour during joint movement was evaluated ((ie, movement of the DC sign together with subchondral bone (DC sign), or in the opposite direction (pseudo DC sign)). RESULTS: Eighty-one patients with gout and 84 patients with CPPD underwent US assessment. Among them, 47 patients with gout and 9 patients with CPPD had evidence of the DC sign. During dynamic assessment, in all 47/47 patients with gout there was a DC sign. Conversely, in 7/9 (77.8%) patients with CPPD, there was a pseudo DC sign (p<0.01).The presence of DC sign during static assessment had a sensitivity, specificity and accuracy of 58.0% (95% CI 46.5% to 68.9%), 89.3% (95% CI 80.6% to 95.0%) and 73.9% (95% CI 66.5% to 80.5%) for gout, respectively. The dynamic evaluation improved the DC sign's diagnostic performance (p=0.01) as the specificity (97.6% (95% CI 91.7% to 99.7%)) and the accuracy (78.2% (95% CI 71.1% to 84.2%)) increased without loss in sensitivity. CONCLUSION: The dynamic US assessment of the DC sign may help to differentiate the DC sign due to MSU crystals from the pseudo DC sign seen in CPPD, as they move in opposite directions.

Doppler Signal and Bone Erosions at the Enthesis Are Independently Associated With Ultrasound Joint Erosive Damage in Psoriatic Arthritis.

OBJECTIVE: To explore the association of the Outcome Measures in Rheumatology ultrasound (US) entheseal abnormalities with the presence of US joint bone erosions in psoriatic arthritis (PsA). METHODS: Consecutive patients with PsA were included in this cross-sectional study. Demographic and clinical variables were collected. A bilateral US assessment was carried out at the following entheses: plantar fascia, and the quadriceps, patellar (proximal and distal), and Achilles tendons. The following US entheseal abnormalities were registered: hypoechogenicity, thickening, Doppler signal < 2 mm from the bony cortex, calcification/enthesophyte, and bone erosion. The presence of US joint bone erosions was investigated at the second and fifth metacarpophalangeal joints, ulnar head, and fifth metatarsophalangeal (MTP) joint, bilaterally, as well as at the level of the most inflamed joint on physical examination. Multiple linear regression analysis was performed to identify clinical and/or US variables associated with US-detected joint bone erosions. RESULTS: A total of 104 patients with PsA were enrolled. At least 1 joint bone erosion was found in 47 of 104 patients (45.2%). Bone erosions were most frequently detected at the fifth MTP joint level (42/208 joints [20.2 %] in 32/104 patients [30.8%]). In the multivariate model, only a power Doppler (PD) signal at the enthesis (P < 0.001, standardized ß = 0.51), bone erosions at the enthesis (P = 0.02, standardized ß = 0.20), PsA disease duration (P = 0.04, standardized ß = 0.17), and greyscale joint synovitis (P = 0.03, standardized ß = 0.42) were associated with US-detected joint bone erosions. CONCLUSION: PD signal and bone erosions at the enthesis represent sonographic biomarkers of a more severe subset of PsA in terms of US-detected joint erosive damage.

Ultrasonography in the prediction of gout flares: a 12-month prospective observational study.

OBJECTIVES: To evaluate whether US findings indicating MSU deposits and US-detected inflammation (i.e. power Doppler signal) predict gout flares over 12 months. METHODS: Gout patients on urate-lowering therapy for at least the preceding 6 months were enrolled consecutively in this 12-month prospective, observational, single-centre study. A nested case-control analysis was performed. Cases were participants with at least one flare in the follow-up period, while controls did not self-report any gout flare. The US assessment included elbows, wrists, second MCP joints, knees, ankles, and first MTP joints. The US findings indicating MSU deposits [i.e. aggregates, double contour (DC) sign and tophi] were identified as present/absent according to the Outcome Measure in Rheumatology definitions. Power Doppler signal was scored semiquantitatively. Summated scores were calculated for each US finding. RESULTS: Eighty-one gout participants were enrolled, and 71 completed the study. Thirty (42.3%) of 71 participants experienced at least one flare over 12 months, with a median of 2.0 flares. Cases had a greater US burden of MSU deposits (6.7 ± 4.7 vs 2.9 ± 2.6, P = 0.01) and power Doppler signal (3.73 ± 3.53 vs 0.82 ± 1.44, P < 0.01) than controls, at baseline. The baseline US scores indicating MSU deposits and US-detected inflammation were significantly associated with the occurrence (total MSU score, adjusted odds ratio:1.75, 95% CI: 1.26, 2.43; power Doppler score, adjusted odds ratio: 1.63, 95% CI: 1.12, 2.40) and the number (total MSU score, adjusted incidence risk ratio: 1.17, 95% CI: 1.08, 1.26; power Doppler score, adjusted incidence risk ratio: 1.29, 95% CI: 1.19, 1.40) of flares over 12 months in multivariate analyses. CONCLUSIONS: Baseline US findings indicating MSU deposits and US-detected inflammation are independent predictors of gout flares over 12 months.

In patients with acute mono/oligoarthritis, a targeted ultrasound scanning protocol shows great accuracy for the diagnosis of gout and CPPD.

OBJECTIVES: To determine an US scanning protocol with the best accuracy for the diagnosis of gout and CPPD in patients with acute mono/oligo-arthritis of unknown origin. METHODS: Patients with acute mono/oligo-arthritis in whom a joint aspiration at the most clinically involved joint (target joint) was requested were consecutively enrolled. US was performed in each patient before the arthrocentesis. The accuracy of different US findings and scanning protocols for the diagnosis of gout and CPPD was calculated. RESULTS: A total of 161 subjects were included (32 gout patients, 30 CPPD patients and 99 disease-controls). US findings had a high specificity for gout (0.92-0.96) and CPPD (0.90-0.97), while the sensitivity ranged from 0.73 to 0.85 in gout (double contour sign and tophi, respectively) and from 0.60 to 0.90 in CPPD (hyaline and fibrocartilage deposits, respectively). The US assessment of two joints bilaterally (gout: knees, MTP1 joints; CPPD: knees, wrists) plus the target joint had an excellent diagnostic sensitivity (gout: 0.91, CPPD: 0.93) and specificity (gout: 0.91, CPPD: 0.89). This targeted US scanning protocol yielded to higher diagnostic accuracy compared with the US evaluation of the target joint [gout area under the curve (AUC) 0.91 vs 0.84, P = 0.03; CPPD AUC 0.93 vs 0.84, P = 0.04] unless the target joint was the knee or the MTP1 joint in gout and the knee or the wrist in CPPD. CONCLUSIONS: A targeted US scanning protocol of two joints bilaterally plus the target joint showed an excellent accuracy (>90%) for the diagnosis of crystal arthritis in patients with acute mono/oligoarthritis.

A real-world economic analysis of biologic therapies for psoriatic arthritis in Italy: results of the CHRONOS observational longitudinal study.

BACKGROUND: Psoriatic arthritis (PsA) is a chronic, immune-mediated, spondyloarthropathy characterised by musculoskeletal signs and symptoms with associated joint pain and tenderness. The average worldwide PsA prevalence is 133/100,000, while in the Italian population is 90-420/100,000. Traditionally, nonsteroidal anti-inflammatory drugs, glucocorticoid, and disease-modifying antirheumatic drugs have been used in the treatment of PsA. However, for those patients who are not adequately controlled with conventional therapies, the new biologics compounds represent a valid option. Biologic therapies have been shown to be more effective but also more expensive than conventional systemic treatments. Based on the CHRONOS study, the economic analyses presented in this paper aim to assess the annualised direct costs and the cost-per-responder of biologics in a real-world context assuming the Italian National Health System perspective. METHODS: The economic assessments were carried out on the overall cohort of patients, and on the tumour necrosis factor alpha inhibitors (TNFi) and the secukinumab subgroup, the most prescribed biologic therapies within the CHRONOS study. RESULTS: The annual economic impact of PsA in the overall group was €12,622, €11,725 in the secukinumab subgroup, and €12,791 in the TNFi subgroup. Biologics absorbed the main expenditure costs in the treatment of PsA accounting for about the 93% of total costs. At 6 months, secukinumab performed better in all the considered outcomes: cost-per-responder according to EULAR DAS28 and ACR50 response criteria were €12,661- €28,975, respectively, while they were €13,356 - €33,368 in the overall cohort and €13,138 - €35,166 in the TNFi subgroup. At 12 months secukinumab remained the subgroup with the lowest cost-per-responder ratio in EULAR DAS28 and ACR50 response criteria, while TNFi subgroup was the lowest one considered the ACR20. CONCLUSION: Despite some potential methodological limitations, our cost-per-response analysis provides physicians and payers additional insights which can complement the traditional risk-benefit profile assessment and drive treatment decisions.

Real-world evidence of biologic treatments in psoriatic arthritis in Italy: results of the CHRONOS (EffeCtiveness of biologic treatments for psoriatic artHRitis in Italy: an ObservatioNal lOngitudinal Study of real-life clinical practice) observational longitudinal study.

BACKGROUND: Biologics have demonstrated efficacy in PsA in randomized clinical trials. More evidence is needed on their effectiveness under real clinical practice conditions. The aim of the present work is to provide real-world evidence of the effectiveness of biologics for PsA in the daily clinical practice. METHODS: CHRONOS was a multicenter, non-interventional, cohort study conducted in 20 Italian hospital rheumatology clinics. RESULTS: 399 patients were eligible (56.9% females, mean (SD) age: 52.4 (11.6) years). The mean (SD) duration of PsA and psoriasis was 7.2 (6.9) and 15.3 (12.2) years, respectively. The mean (SD) duration of the biologic treatment under analysis was 18.6 (6.5) months. The most frequently prescribed biologic was secukinumab (40.4%), followed by adalimumab (17.8%) and etanercept (16.5%). The proportion of overall responders according to EULAR DAS28 criteria was 71.8% (95% CI: 66.7-76.8%) out of 308 patients at 6 months and 68.0% (95% CI: 62.7-73.3%) out of 297 patients at 1 year. Overall, ACR20/50/70 responses at 6 months were 41.2% (80/194), 29.4% (57/194), 17.1% (34/199) and at 1-year were 34.9% (66/189), 26.7% (51/191), 18.4% (36/196), respectively. Secondary outcome measures improved rapidly already at 6 months: mean (SD) PASI, available for 87 patients, decreased from 3.2 (5.1) to 0.6 (1.3), the proportion of patients with dactylitis from 23.6% (35/148) to 3.5% (5/142) and those with enthesitis from 33.3% (49/147) to 9.0% (12/133). CONCLUSIONS: The CHRONOS study provides real-world evidence of the effectiveness of biologics in PsA in the Italian rheumatological practice, confirming the efficacy reported in RCTs across various outcome measures.

Muscle involvement in systemic lupus erythematosus: multimodal ultrasound assessment and relationship with physical performance.

OBJECTIVES: The objectives of this study were (1) to explore US findings for muscle mass, muscle quality and muscle stiffness in SLE patients and healthy subjects; (2) to investigate the relationship between the US muscle findings and physical performance in SLE patients and healthy subjects. METHODS: Quadriceps muscle thickness was used for assessment of muscle mass, muscle echogenicity (using a visual semi-quantitative scale and grayscale analysis with histograms) for assessment of muscle quality, and point shear-wave elastography (SWE) for assessment of muscle stiffness in 30 SLE patients (without previous/current myositis or neuromuscular disorders) and 15 age-, sex- and BMI-matched healthy subjects. Hand grip strength tests and short physical performance battery (SPPB) tests were carried out in the same populations. RESULTS: No difference was observed between SLE patients and healthy subjects for quadriceps muscle thickness (35.2 mm ±s.d. 6.8 vs 34.8 mm ± s.d. 6.0, respectively, P = 0.79). Conversely, muscle echogenicity was significantly increased in SLE patients (visual semi-quantitative scale: 1.7 ± s.d. 1.0 vs 0.3 ± s.d. 0.5, respectively, P < 0.01; grayscale analysis with histograms: 87.4 mean pixels ± s.d. 18.8 vs 70.1 mean pixels ± s.d. 14.0, respectively, P < 0.01). Similarly, SWE was significantly lower in SLE patients compared with healthy subjects {1.5 m/s [interquartile range (IQR) 0.3] vs 1.6 m/s (IQR 0.2), respectively, P = 0.01}. Muscle echogenicity was inversely correlated with grip strength (visual semi-quantitative scale, Rho: -0.47, P = 0.01; grayscale analysis with histograms, Rho: -0.41, p < 0.01) and SPPB (visual semi-quantitative scale, Rho: -0.50, P < 0.01; grayscale analysis with histograms Rho: -0,46, P < 0.01). CONCLUSIONS: US assessment of muscle echogenicity and stiffness is useful for the early detection of muscle involvement in SLE patients.

Development of a convolutional neural network for the identification and the measurement of the median nerve on ultrasound images acquired at carpal tunnel level.

BACKGROUND: Deep learning applied to ultrasound (US) can provide a feedback to the sonographer about the correct identification of scanned tissues and allows for faster and standardized measurements. The most frequently adopted parameter for US diagnosis of carpal tunnel syndrome is the increasing of the cross-sectional area (CSA) of the median nerve. Our aim was to develop a deep learning algorithm, relying on convolutional neural networks (CNNs), for the localization and segmentation of the median nerve and the automatic measurement of its CSA on US images acquired at the proximal inlet of the carpal tunnel. METHODS: Consecutive patients with rheumatic and musculoskeletal disorders were recruited. Transverse US images were acquired at the carpal tunnel inlet, and the CSA was manually measured. Anatomical variants were registered. The dataset consisted of 246 images (157 for training, 40 for validation, and 49 for testing) from 103 patients each associated with manual annotations of the nerve boundary. A Mask R-CNN, state-of-the-art CNN for image semantic segmentation, was trained on this dataset to accurately localize and segment the median nerve section. To evaluate the performances on the testing set, precision (Prec), recall (Rec), mean average precision (mAP), and Dice similarity coefficient (DSC) were computed. A sub-analysis excluding anatomical variants was performed. The CSA was automatically measured by the algorithm. RESULTS: The algorithm correctly identified the median nerve in 41/49 images (83.7%) and in 41/43 images (95.3%) excluding anatomical variants. The following metrics were obtained (with and without anatomical variants, respectively): Prec 0.86 ± 0.33 and 0.96 ± 0.18, Rec 0.88 ± 0.33 and 0.98 ± 0.15, mAP 0.88 ± 0.33 and 0.98 ± 0.15, and DSC 0.86 ± 0.19 and 0.88 ± 0.19. The agreement between the algorithm and the sonographer CSA measurements was excellent [ICC 0.97 (0.94-0.98)]. CONCLUSIONS: The developed algorithm has shown excellent performances, especially if excluding anatomical variants. Future research should aim at expanding the US image dataset including a wider spectrum of normal anatomy and pathology. This deep learning approach has shown very high potentiality for a fully automatic support for US assessment of carpal tunnel syndrome.

Ultrasound findings of calcium pyrophosphate deposition disease at metacarpophalangeal joints.

OBJECTIVE: To explore the spectrum of articular and peri-articular ultrasound (US) findings at metacarpophalangeal (MCP) joints in calcium pyrophosphate (CPP) deposition disease (CPPD). METHODS: Consecutive CPPD patients (chronic CPP crystal inflammatory arthritis or OA with CPPD), and age- and sex-matched controls with RA were prospectively enrolled. Patients underwent bilateral US examination of MCP joints. CPP deposits, synovial inflammation, osteophytes, cartilage damage and bone erosions were recorded. RESULTS: Sixty CPPD patients (33, 55.0% with OA with CPPD and 27, 45.0% with chronic CPP crystal inflammatory arthritis) and 40 RA patients were enrolled. CPP deposits were detected in 24 (40.0%) CPPD patients and in 3 (7.5%) RA patients (P <0.01). In CPPD patients, different types of CPP deposits were identified at MCP joints: 17 (28.3%) patients had dorsal capsuloligamentous deposits, 14 (23.3%) intra-cartilaginous deposits, 13 (21.7%) lateral capsuloligamentous deposits, 12 (20.0%) intra-articular deposits, eight (13.3%) double contour sign and five (8.3%) flexor digitorum tendons' deposits. CPPD patients with chronic CPP crystal inflammatory arthritis showed more US findings indicating synovial inflammation and CPP deposits than those with OA with CPPD. Conversely, a higher prevalence of US features indicating structural damage was noted in this latter phenotype. CPP deposits and bone erosions were the US findings with the highest value for diagnosing chronic CPP crystal inflammatory arthritis and RA, respectively. CONCLUSION: This study provides pictorial evidence of the broad spectrum of US findings indicating CPP deposits at MCP joints in CPPD. Furthermore, we reported different US patterns in different CPPD phenotypes.

A deep-learning framework for metacarpal-head cartilage-thickness estimation in ultrasound rheumatological images.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic disease characterized by erosive symmetrical polyarthritis. Bone and cartilage are the main joint targets of this disease. Cartilage damage is one of the most relevant determinants of physical disability in RA patients. Cartilage damage is nowadays assessed by clinicians, which manually measure cartilage thickness in ultrasound (US) imaging. This poses issues relevant to intra-and inter-observer variability. Relying on the acquisition of metacarpal-head US images from 38 subjects, this work addresses the problem of automatic cartilage-thickness measurement by designing a new deep-learning (DL) framework. METHODS: The framework consists of a Convolutional Neural Network (CNN), responsible for regressing cartilage-interface distance fields, followed by a post-processing step to delineate the two cartilage interfaces from the predicted distance fields and compute the cartilage thickness. RESULTS: Our framework achieved encouraging results with a mean absolute difference (ADF) of 0.032 (±0.026) mm against manual thickness annotation by an expert clinician. When evaluating the intra-observer variability, we obtained an ADF = 0.036 (±0.028) mm. CONCLUSION: The proposed framework achieved an ADF against manual annotation that was comparable to the intra-observer variability, proving the potential of DL in the field. SIGNIFICANCE: This work is the first to address the problem of automatic cartilage-thickness estimation in US rheumatological images with DL, paving the way for future research in the field. From a clinical perspective, the proposed framework proved to be a valuable tool to support the clinical routine increasing the reproducibility of cartilage thickness measurements.

Sonographic assessment of cartilage damage at the metacarpal head in rheumatoid arthritis: qualitative versus quantitative methods.

OBJECTIVE: To test the validity of the OMERACT semi-quantitative score by comparing with a quantitative method in the US assessment of hyaline cartilage at the metacarpal head (MH) in patients with RA and healthy controls (HCs). METHODS: The hyaline cartilage from the second to fifth MHs of both hands was scanned. Hyaline cartilage was scored semi-quantitatively and quantitatively by measuring cartilage thickness and comparing with reference values. In RA patients, radiographic joint space narrowing (JSN) was scored on the same joints using the Simple Erosion Narrowing Score (SENS). RESULTS: A total of 408 MHs in 51 RA patients and 320 MHs in 40 HSs were evaluated. The OMERACT semi-quantitative score was quicker to perform than the quantitative method [6.0 min (s.d. 0.5) vs 8.0 (1.5); P < 0.01]. A significant correlation between the US scores (R = 0.68) and between the US scores and the JSN-SENS (R = 0.61 and R = 0.63 for the semi-quantitative and quantitative method, respectively) was found. The frequency of cartilage abnormalities was similar between the two US methods in RA patients (58.8% and 51.0% of RA patients for the semi-quantitative and quantitative method, respectively; P = 0.46), while the former revealed more abnormalities in HCs (27.5% and 7.5% of HCs; P = 0.02). CONCLUSION: The higher feasibility of the OMERACT semi-quantitative score suggests its use as a first-choice method in the evaluation of cartilage damage. However, despite its limits, the quantitative assessment of HCs, providing patient-tailored information with age- and sex-corrected cut-off values, may represent a valid supplement for optimizing the evaluation of cartilage damage in selected cases.

The Reliability of Ultrasound in the Assessment of Hyaline Cartilage in Rheumatoid Arthritis and Healthy Metacarpal Heads.

PURPOSE: i) To assess the inter- and intra-observer reliability of ultrasound (US) in the evaluation of the hyaline cartilage (HC) of the metacarpal head (MH) in patients with rheumatoid arthritis (RA) and in healthy subjects (HS) both qualitatively and quantitatively. ii) To calculate the smallest detectable difference (SDD) of the MH cartilage thickness measurement. iii) To correlate the qualitative scoring system and the quantitative assessment. MATERIALS AND METHODS: US examination was performed on 280 MHs of 20 patients with RA and 15 HS using a very high frequency probe (up to 22 MHz). HC status was evaluated both qualitatively (using a five-grade scoring system) and quantitatively (using the average value of the longitudinal and transverse measures). The HC of MHs from II to V metacarpophalangeal joint of both hands were scanned independently on the same day by two rheumatologists to assess inter-observer reliability. All subjects were re-examined using the same scanning protocol and the same US setting by one sonographer after a week to assess intra-observer reliability. RESULTS: The inter-observer agreement and intra-observer agreement were moderate to substantial (k = 0.66 and k = 0.73) for the qualitative scoring system and high (ICC = 0.93 and ICC = 0.94) for the quantitative assessment. The SDD of the MH cartilage thickness measurement was 0.09 mm. A significant correlation between the two scoring systems was found (r = -0.35; p < 0.001). CONCLUSION: The present study describes the main methodological issues of HC assessment. Using a standardized protocol, both the qualitative and the quantitative scoring systems can be reliable.

Enthesitis in Psoriatic Arthritis, the Sonographic Perspective.

PURPOSE OF REVIEW: To provide an overview of the ultrasound (US) studies focusing on enthesitis in psoriatic arthritis (PsA). RECENT FINDINGS: Last-generation US equipment has demonstrated the ability to detect subtle morphostructural and vascular abnormalities at entheseal level. US is able to identify pathologic changes in both "classical" (i.e., the site of attachment of tendons, ligaments, and joint capsules into the bone) and "functional" entheses (i.e., anatomical regions where tendons or ligaments wrap around bony pulleys). US has the potential to be the first-line method in the assessment of enthesitis. In the present review we critically discussed the current definitions of US enthesitis, the scoring systems, and the main fields of application (i.e., the detection of enthesitis in PsA and psoriasis, the identification of different disease subsets, and the assessment of response to treatment).

Imaging of Joint and Soft Tissue Involvement in Systemic Lupus Erythematosus.

PURPOSE OF REVIEW: To highlight the potential uses and applications of imaging in the assessment of the most common and relevant musculoskeletal (MSK) manifestations in systemic lupus erythematosus (SLE). RECENT FINDINGS: Ultrasound (US) and magnetic resonance imaging (MRI) are accurate and sensitive in the assessment of inflammation and structural damage at the joint and soft tissue structures in patients with SLE. The US is particularly helpful for the detection of joint and/or tendon inflammation in patients with arthralgia but without clinical synovitis, and for the early identification of bone erosions. MRI plays a key role in the early diagnosis of osteonecrosis and in the assessment of muscle involvement (i.e., myositis and myopathy). Conventional radiography (CR) remains the traditional gold standard for the evaluation of structural damage in patients with joint involvement, and for the study of bone pathology. The diagnostic value of CR is affected by the poor sensitivity in demonstrating early structural changes at joint and soft tissue level. Computed tomography allows a detailed evaluation of bone damage. However, the inability to distinguish different soft tissues and the need for ionizing radiation limit its use to selected clinical circumstances. Nuclear imaging techniques are valuable resources in patients with suspected bone infection (i.e., osteomyelitis), especially when MRI is contraindicated. Finally, dual energy X-ray absorptiometry represents the imaging mainstay for the assessment and monitoring of bone status in patients with or at-risk of osteoporosis. Imaging provides relevant and valuable information in the assessment of MSK involvement in SLE.