The role of Doppler ultrasound in rheumatic diseases

Multimodal PA/US imaging in Rheumatoid Arthritis: Enhanced correlation with clinical scores

Background

Accurate assessment of Rheumatoid Arthritis (RA) activity remains a challenge. Multimodal photoacoustic/ultrasound (PA/US) joint imaging emerges as a novel imaging modality capable of depicting microvascularization and oxygenation levels in inflamed joints associated with RA. However, the scarcity of large-scale studies limits the exploration of correlating joint oxygenation status with disease activity.

Objective

This study aimed to explore the correlation between multimodal PA/US imaging scores and RA disease activity, assessing its clinical applicability in managing RA.

Methods

In this study, we recruited 111 patients diagnosed with RA and conducted examinations of seven small joints on their clinically dominant side using a PA/US imaging system. The PA and power Doppler ultrasound (PDUS) signals were semi-quantitatively assessed using a 0-3 grading system. The cumulative scores for PA and PDUS across these seven joints (PA-sum and PDUS-sum) were calculated. Relative oxygen saturation (So2) values of inflamed joints on the clinically dominant side were measured, and categorized into four distinct PA+So2 patterns. The correlation between PA/US imaging scores and disease activity indices was systematically evaluated.

Results

Analysis of 777 small joints in 111 patients revealed that the PA-sum scores exhibited a strong positive correlation with standard clinical scores for RA, including DAS28 [ESR] (ρ = 0.682), DAS28 [CRP] (ρ = 0.683), CDAI (ρ = 0.738), and SDAI (ρ = 0.739), all with p < 0.001. These correlations were superior to those of the PDUS-sum scores (DAS28 [ESR] ρ = 0.559, DAS28 [CRP] ρ = 0.555, CDAI ρ = 0.575, SDAI ρ = 0.581, p < 0.001). Significantly, in patients with higher PA-sum scores, notable differences were observed in the erythrocyte sedimentation rate (ESR) (p < 0.01) and swollen joint count 28 (SJC28) (p < 0.01) between hypoxia and intermediate groups. Notably, RA patients in the hypoxia group exhibited higher clinical scores in certain clinical indices.

Conclusion

Multi-modal PA/US imaging introduces potential advancements in RA assessment, especially regarding So2 evaluations in synovial tissues and associated PA scores. However, further studies are warranted, particularly with more substantial sample sizes and in multi-center settings.

Summary

This study utilized multi-modal PA/US imaging to analyze Rheumatoid Arthritis (RA) patients' synovial tissues and affected joints. When juxtaposed with traditional PDUS imaging, the PA approach demonstrated enhanced sensitivity, especially concerning detecting small vessels in thickened synovium and inflamed tendon sheaths. Furthermore, correlations between the derived PA scores, PA+So2 patterns, and standard clinical RA scores were observed. These findings suggest that multi-modal PA/US imaging could be a valuable tool in the comprehensive assessment of RA, offering insights not only into disease activity but also into the oxygenation status of synovial tissues. However, as promising as these results are, further investigations, especially in larger and diverse patient populations, are imperative.

Key points

⸸ Multi-modal PA/US Imaging in RA: This novel technique was used to assess the So2 values in synovial tissues and determine PA scores of affected RA joints.⸸ Correlation significantly with Clinical RA Scores: Correlations significantly were noted between PA scores, PA+So2 patterns, and standard clinical RA metrics, hinting at the potential clinical applicability of the technique.

Application value of shear-wave elastography combined with monochrome superb microvascular imaging in renal allograft chronic rejection

BACKGROUND

Conventional ultrasound (US), which include gray scale US and Doppler US, is the first-line imaging modality for the evaluation of renal allograft; however, conventional US indicators have limitations.

OBJECTIVE

To explore the application value of shear-wave elastography (SWE) combined with monochrome superb microvascular imaging (mSMI) in renal allograft chronic rejection (CR).

METHODS

From November 2021 to February 2022 in the Lanzhou University Second Hospital, the US features of 54 patients with renal allograft were retrospectively analyzed. Patients were categorized into two groups: stable group(n = 44) and CR group(n = 10), with clinical diagnosis as reference standard. The vascular index (VI) on mSMI and parenchymal stiffness were measured in the middle cortex of all renal allografts and receiver operating characteristic (ROC) curves were drawn to evaluate the feasibility of differentiation. Statistically significant US features and biochemical indicators such as creatinine were scored, and the results of the scores were analyzed by ROC curve.

RESULTS

The VI on mSMI of the stable group (49.5±2.0) was significantly greater than that of the CR group (33.8±5.9) (P = 0.028). There was a statistically significant difference in parenchymal stiffness between stable group (16.2kPa±1.2) and CR group (33.9kPa±6.6) (P = 0.027). The sensitivity was 90% and specificity was 81.8% of the scores in the differentiation of stable group from CR group (cut-off value, 2; P = 0.000).

CONCLUSION

SWE combined with mSMI may help differentiate stable renal allograft from renal allograft CR and have the potential application value in the diagnosis of renal allograft CR.

Power Doppler artifacts in evaluating inflammatory arthritis of small joints: comparison with a superb microvascular imaging technique

Conventional Doppler techniques provide clinical information about tissue vascularisation, but they have limitations in detecting low-velocity blood flow. The innovative Doppler technique called superb microvascular imaging provides visualization of microvascular flow never seen before with the ultrasound. The new tool suppresses the noise caused by motion artifacts with an innovative filter system without removing the weak signal arising from small vessel flow, hence it achieves a greater sensitivity than power Doppler. Explanation of motion artifact genesis reveals SMI imaging principles and helps to distinguish false-positive results. Due to the higher SMI sensitivity to flow, there are nuances in the interpretation of other artifacts as well as motion. The paper presents commonly encountered artifacts of power Doppler compared with a novel microvascular imaging technique focused on a small joints inflammation. The main attention is intent on the practical recommendations for ultrasound machine settings and evaluation of comparable images.

Muscle B mode ultrasound and shear-wave elastography in idiopathic inflammatory myopathies (SWIM): criterion validation against MRI and muscle biopsy findings in an incident patient cohort

Background

B mode ultrasound (US) and shear wave elastography (SWE) are easily accessible imaging tools for idiopathic inflammatory myopathies (IIM) but require further validation against standard diagnostic procedures such as MRI and muscle biopsy.

Methods

In this prospective cross-sectional study we compared US findings to MRI and muscle biopsy findings in a group of 18 patients (11 F, 7 M) with active IIM (dermatomyositis 6, necrotising autoimmune myopathy 7, inclusion body myositis 4, overlap myositis 1) who had one or both procedures on the same muscle. US domains (echogenicity, fascial thickness, muscle bulk, shear wave speed and power doppler) in the deltoid and vastus lateralis were compared to MRI domains (muscle oedema, fatty infiltration/atrophy) and muscle biopsy findings (lymphocytic inflammation, myonecrosis, atrophy and fibro-fatty infiltration). A composite index score (1–4) was also used as an arbitrary indicator of overall muscle pathology in biopsies.

Results

Increased echogenicity correlated with the presence of fatty infiltration/atrophy on MRI (p = 0.047) in the vastus lateralis, and showed a non-significant association with muscle inflammation, myonecrosis, fibrosis and fatty infiltration/atrophy (p > 0.333) Severe echogenicity also had a non-significant association with higher composite biopsy index score in the vastus lateralis (p = 0.380). SWS and US measures of fascial thickness and muscle bulk showed poor discrimination in differentiating between pathologies on MRI or muscle biopsy. Power Doppler measures of vascularity correlated poorly with the presence of oedema on MRI, or with inflammation or fatty infiltration on biopsy. Overall, US was sensitive in detecting the presence of muscle pathology shown on MRI (67–100%) but showed poorer specificity (13–100%). Increased echogenicity showed good sensitivity when detecting muscle pathology (100%) but lacked specificity in differentiating muscle pathologies (0%). Most study participants rated US as the preferred imaging modality.

Conclusions

Our findings show that US, in particular muscle echogenicity, has a high sensitivity, but low specificity, for detecting muscle pathology in IIM. Traditional visual grading scores are not IIM-specific and require further modification and validation. Future studies should continue to focus on developing a feasible scoring system, which is reliable and allows translation to clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-022-00276-w.

Blood Flow in the Anterior Humeral Circumflex Artery Reflects Synovial Inflammation of the Shoulder Joint in Rotator Cuff Tears

Background

An association has been reported between rotator cuff tear and inflammation. We hypothesized that blood flow in the anterior humeral circumflex artery would reflect synovial inflammation in the shoulder. This study aimed to clarify the association of blood flow in the anterior humeral circumflex artery with synovial inflammation and shoulder pain in patients with rotator cuff tears.

Methods

In this prospective, cross-sectional study, tissue samples from the synovium in the rotator interval were obtained from 33 patients undergoing arthroscopic rotator cuff repair. Reverse transcription-polymerase chain reaction and real-time polymerase chain reaction were performed to determine the messenger RNA expression of inflammatory mediators, growth factors, and matrix metalloproteinases. Additional tissue samples were fixed for histologic evaluation. Before surgery, we measured the peak systolic velocity in the anterior humeral circumflex artery using pulse Doppler ultrasonography.

Results

The peak systolic velocity in the anterior humeral circumflex artery was positively correlated with the messenger RNA expression of interleukin 1β, interleukin 8, and matrix metalloproteinase 3 genes (r = 0.49, P = .004; r = 0.55, P = .001; and r = 0.39, P = .026, respectively), as well as histologic synovitis scores (r = 0.48, P = .005). Additionally, it was significantly higher in patients with resting pain than in those without resting pain (P = .048).

Conclusion

The peak systolic velocity in the anterior humeral circumflex artery is associated with the severity of synovial inflammation. Our results suggest that assessing the peak systolic velocity in the anterior humeral circumflex artery is useful for evaluating the severity of synovial inflammation.

Bone Erosions Detected by Ultrasound Are Prognostic for Clinical Arthritis Development in Patients With ACPA and Musculoskeletal Pain

Anti-citrullinated protein antibodies (ACPA) often precede onset of rheumatoid arthritis (RA) by years, and there is an urgent clinical need for predictors of arthritis development among such at-risk patients. This study assesses the prognostic value of ultrasound for arthritis development among ACPA-positive patients with musculoskeletal pain. We prospectively followed 82 ACPA-positive patients without clinical signs of arthritis at baseline. Ultrasound at baseline assessed synovial hypertrophy, inflammatory activity by power Doppler, and erosions in small joints of hands and feet. We applied Cox regression analyses to examine associations with clinical arthritis development during follow-up (median, 69 months; range, 24–90 months). We also compared the ultrasound findings among the patients to a control group of 100 blood donors without musculoskeletal pain. Clinical arthritis developed in 39/82 patients (48%) after a median of 6 months (range, 1–71 months). One or more ultrasound erosions occurred in 13/82 patients (16%), with none in control subjects (p < 0.001). Clinical arthritis development was more common among patients with baseline ultrasound erosions than those without (77 vs. 42%, p = 0.032), and remained significant in a multivariable Cox regression analysis that included previously described prognostic factors (HR 3.9, 95% CI 1.6–9.4, p = 0.003). Ultrasound-detected tenosynovitis was more frequent among the patients and associated with clinical arthritis development in a univariable analysis (HR 2.5, 95% CI 1.1–5.7, p = 0.031), but did not remain statistically significant in multivariable analysis. Thus, bone erosions detected by ultrasound are independent predictors of clinical arthritis development in an ACPA-positive at-risk population.

Trial Registration: Regional Ethics Committee in Linköping, Sweden, Dnr M220-09. Registered 16 December 2009, https://etikprovningsmyndigheten.se/.

Advanced Musculoskeletal Ultrasound Techniques: What Are the Applications?

OBJECTIVE. The purpose of this article is to cover technical advances in musculo-skeletal ultrasound from the viewpoint of the radiologist. CONCLUSION. Among the advances in musculoskeletal ultrasound that we highlight the use of ultrahigh-frequency transducers to visualize ever-finer anatomic detail, the expanding practical clinical applications for microvascular imaging, and the use of elastography to predict function and, possibly, healing potential.

Sentinel joint scoring in rheumatoid arthritis: an individualized power Doppler assessment strategy

OBJECTIVE

Musculoskeletal ultrasound quantifies the total synovial inflammatory burden in rheumatoid arthritis (RA) but is time consuming when scanning numerous joints. This study evaluated a novel patient-centered method for constructing a longitudinal ultrasound score in RA patients.

METHODS

Fifty-four RA patients starting intravenous tocilizumab were evaluated with power Doppler ultrasound (PDUS) of 34 joints and DAS28-ESR was assessed at baseline and weeks 4, 12, 16, and 24. The sentinel joint score (SJS) was derived from the reduced subset of joints with PDUS ≥ 1 at baseline. Total PDUS (tPDUS) score and US7 were also calculated. Changes in tPDUS and SJS were correlated. Effect sizes were calculated for tPDUS, SJS, and US7. The proportion of "flipped" joints without baseline PDUS signal that later developed PDUS signal was estimated.

RESULTS

At baseline, 1236/1829 joints scanned (67.5%) did not have PDUS signal. The proportion of "flipped" joints at 24 weeks was 5.6% for ≥ 1, 2.9% for ≥ 2, and 1.0% for = 3 PD. tPDUS and SJS scores were highly correlated (r = 0.91 to 0.97). Overall the effect sizes for tPDUS, SJS, and US7 increased over 24 weeks, where SJS was the highest (SJS 1.00 4-week, 1.07 12-week, 1.26 24-week) and tPDUS and US7 were comparable (tPDUS 0.32 4-week, 0.52 12-week, 0.84 24-week; US7 0.23 4-week, 0.52 12-week, 0.74 24-week).

CONCLUSION

In RA patients starting a biologic, scanning only joints with baseline PDUS signal can substantially reduce the number of joints requiring follow-up scanning by 67.5% and improves feasibility. "Flipped" joints are infrequently seen after starting therapy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01717859 Key messages • Only a small percent of joints develop power Doppler signal after baseline scanning. • Changes in the SJS correlate well with changes in clinical activity measured by DAS28-ESR over time. • The SJS effect size is higher than total PDUS and US7 scores, and may improve examination feasibility.

Power Doppler in musculoskeletal ultrasound: uses, pitfalls and principles to overcome its shortcomings

Power Doppler (PD) is used widely in musculoskeletal ultrasound, especially in the assessment of structures for evidence of inflammation and in evaluating soft tissue neoplasms. We reinforce and delineate the three cardinal principles of optimising PD assessment in order to avoid false positive or false negative results; namely (1) Optimal gain settings (2) Adequate transducer pressure, and (3) Proper patient/anatomical structure-of-interest positioning with complete tissue relaxation.

Thermography and colour Doppler ultrasound: a potential complementary diagnostic tool in evaluation of rheumatoid arthritis in the knee region

The aim and objectives of this study were as follows: (i) to perform automated segmentation of knee thermal image using the regional isotherm-based segmentation (RIBS) algorithm and segmentation of ultrasound image using the image J software; (ii) to implement the RIBS algorithm using computer-aided diagnostic (CAD) tools for classification of rheumatoid arthritis (RA) patients and normal subjects based on feature extraction values; and (iii) to correlate the extracted thermal imaging features and colour Doppler ultrasound (CDUS) features in the knee region with the biochemical parameters in RA patients. Thermal image analysis based on skin temperature measurement and thermal image segmentation was performed using the RIBS algorithm in the knee region of RA patients and controls. There was an increase in the average skin temperature of 5.94% observed in RA patients compared to normal. CDUS parameters such as perfusion, effusion and colour fraction for the RA patients were found to be 1.2 ± 0.5, 1.8 ± 0.2 and 0.052 ± 0.002, respectively. CDUS measurements were performed and analysed using the image J software. Biochemical parameters such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) showed significant positive correlation with the thermal imaging parameters. The CDUS parameters such as effusion, perfusion and colour fraction correlated significantly with the clinical and functional assessment score. According to the results of this study, both infrared (IR) thermal imaging and CDUS offer better diagnostic potential in detecting early-stage RA. Therefore, the developed CAD model using thermal imaging could be used as a pre-screening tool to diagnose RA in the knee region.

Are OMERACT Knee Osteoarthritis Ultrasound Scores Associated With Pain Severity, Other Symptoms, and Radiographic and Magnetic Resonance Imaging Findings?

OBJECTIVE

To investigate the associations of Outcome Measures in Rheumatology (OMERACT) ultrasound scores for knee osteoarthritis (OA) with pain severity, other symptoms, and OA severity on radiographs and magnetic resonance imaging (MRI).

METHODS

Participants with symptomatic and mild to moderate radiographic knee OA underwent baseline dynamic ultrasound (US) assessment according to standardized OMERACT scanning protocol. Using the published US image atlas, a physician operator obtained semiquantitative or binary scores for US pathologies. Clinical severity was measured on numerical rating scale (NRS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) symptoms and pain subscores. OA severity was assessed using the Kellgren-Lawrence (KL) grade on radiographs and MRI Osteoarthritis Knee Score (MOAKS) on noncontrast-enhanced MRI. Separate linear regression models were used to determine associations of US OA pathologies with pain and KOOS subscores, and Spearman correlations were used for US scores with KL grade and MOAKS.

RESULTS

Eighty-nine participants were included. Greater synovial hypertrophy, power Doppler (PD), and meniscal extrusion scores were associated with worse NRS pain [β 0.92 (95% CI 0.25-1.58), β 0.73 (95% CI 0.11-1.35), and β 1.01 (95% CI 0.22-1.80), respectively]. All greater US scores, except for cartilage grade, demonstrated significant associations with worse KOOS symptoms, whereas only PD and meniscal extrusion were associated with worse KOOS pain. All US scores, except for PD, were significantly correlated with KL grade. US pathologies, except for cartilage, revealed moderate to good correlation with their MOAKS counterparts, with US synovitis having the greatest correlation (0.69, 95% CI 0.60-0.78).

CONCLUSION

OMERACT US scores revealed significant associations with pain severity, KL grade, and MOAKS.

Clinical Applications of Superb Microvascular Imaging in the Liver, Breast, Thyroid, Skeletal Muscle, and Carotid Plaques

This article reviews the clinical applications of Superb Microvascular Imaging (SMI; Canon Medical Systems, Otawara, Japan) in the liver, breast, thyroid, skeletal muscle, and carotid plaques. Diseases that are closely associated with angiogenesis can be diagnosed by SMI in a relatively early phase, and using SMI can prevent adverse reactions associated with the contrast agents used in contrast-enhanced ultrasound. Super Microvascular Imaging also shows particular value in grading disease activities and monitoring therapeutic responses. Although SMI has some limitations, such as a lack of clinical standards, it can add information to conventional ultrasound examinations and may become a noninvasive alternative to invasive diagnostic procedures for many clinical conditions.

Should ultrasound be used routinely in the diagnosis of rheumatoid arthritis?

INTRODUCTION

A growing body of evidence indicates the benefits of early diagnosis of rheumatoid arthritis (RA) and prompt treatment with disease-modifying anti-rheumatic drugs (DMARDS) in terms of relieving symptoms, improving prognosis, and reducing long-term complications. There is however some controversy over the most beneficial method of imaging in providing accurate early diagnosis. Though current practice favours clinical and radiological assessment, this is increasingly supplemented by ultrasound techniques (and, to a lesser extent, CT and MRI scanning). While EULAR and ESSR favour the use of ultrasonography (US) as the first-line investigation in cases of suspected RA, a recent NICE review upholds the traditional place of plain film radiographs of hands and feet to detect erosions as early signs of synovitis. This review considers the evidence for US in the early diagnosis of RA and the case for it becoming the primary assessment modality in rheumatology clinics.

AIMS

This paper aims to assess the current literature on the efficacy of ultrasonography in diagnosing early RA, by comparing US with alternative imaging modalities. The goal is to propose the most appropriate method of diagnosis to improve early initiation of DMARD treatment for optimum disease outcomes.

METHODS

Searches for related studies and review articles were carried out using electronic databases and hand searches. Additional references were gleaned from the bibliographies of included papers. Related articles and pop-outs from PubMed were also used. The search was refined in PubMed, by only using reviews which were written in English and published in past 10 years and had full free text available.

RESULTS

This review confirms that US has a high level of sensitivity in diagnosing RA (and hence a low risk of missing cases of RA which might benefit from early treatment with DMARDs). It also has a high level of specificity (and hence a low risk of falsely diagnosing somebody with RA who may suffer adverse effects of DMARD therapy). US is already widely available and well accepted by clinicians and patients. It does not involve exposure to radiation and can be readily delivered by appropriately trained staff.

CONCLUSION

This review of relevant studies indicates that US should become accepted as the investigation with the most favourable balance of benefits to risks in the early diagnosis of RA. Given the continuing controversy surrounding studies of different imaging techniques in RA, further research into the diagnostic role of US in RA is indicated.

Pain Mechanisms and Ultrasonic Inflammatory Activity as Prognostic Factors in Patients With Psoriatic Arthritis: A Prospective Cohort Study

OBJECTIVE

To study the prognostic value of widespread pain and of musculoskeletal ultrasound (US) examination for subsequent treatment outcomes in patients with psoriatic arthritis (PsA).

METHODS

An exploratory prospective cohort study enrolled patients with PsA initiating biologic or conventional synthetic disease-modifying antirheumatic drugs in routine care. Clinical, US, and patient-reported measures were collected at baseline and after 4 months. Widespread nonarthritic pain (WP) was defined as a Widespread Pain Index score of ≥4 with pain in ≥4 of 5 regions. PsA activity by US was defined as color Doppler (yes/no) in selected entheses, joints, or tendons. The main response criteria included the American College of Rheumatology 20% improvement, the Disease Activity in Psoriatic Arthritis 50% improvement, and minimal disease activity. The primary analyses were age- and sex-adjusted logistic regression.

RESULTS

WP was present in 24 of 69 included patients (35%) and was associated with worse patient-reported and composite baseline measures, while US and other objective findings were similar to those in patients without WP. The odds of reaching minimal disease activity after 4 months were significantly greater for patients enrolled without WP (odds ratio 18.43 [95% confidence interval 1.51, 224.41]; P = 0.022), while WP did not impair other response measures. Patients with baseline color Doppler activity (n = 42 [61%]) had a worse objective PsA burden, but their chance of treatment response was comparable to those without color Doppler.

CONCLUSION

More than one-third of patients with PsA presented with WP, which was associated with worse patient-reported scores and failure to achieve minimal disease activity following conventional synthetic or biologic disease-modifying antirheumatic drug therapy. PsA activity by color Doppler US had no influence on subsequent treatment response in this PsA cohort.

Hierarchical nomenclature in rheumatology

INTRODUCTION

One of the missions of the Spanish Society of Rheumatology is to provide the necessary tools for excellence in health care. Currently, there is no reference point to quantify medical actions in this specialty, and this is imperative.

MATERIAL AND METHOD

A list of actions was drawn up and a hierarchical classification system was established by developing a complexity index, calculated based on the completion time and difficulty level of each action.

RESULTS

The results of the Delphi method tended to the consensus opinion within a group (mean σ2 - σ1=0.75-1.43=-0.68, mean IQR2 - IQR1=0.8-1.9=-1.1). The values of the complexity index ranged between 48 and 465 points. Among consultation actions, those reaching the highest scores were the first inpatient visit (366) and visits to the patient's home (369). Among diagnostic techniques, biopsies were prominent, those with the highest score were: bone biopsy (465), sural nerve biopsy (416) and synovial biopsy (380). Ultrasound scan scored 204, capillaroscopy 113 and densitometry 112. Among therapeutic techniques, infiltration/ arthrocentesis/articular injection in children reached the highest difficulty (388). The score for ultrasound-guided articular injection was 163. The score for clinical report on disability was 323 and expert report 370.

CONCLUSIONS

A nomenclature of 54 actions in Rheumatology was compiled. Biopsies (bone, sural nerve, synovial), inpatient visits, visits to the patient's home, infiltrations in children, and the preparation of the expert report were identified as the most complex actions. Musculoskeletal ultrasound is twice as complex as subsequent visits, capillaroscopy or bone densitometry.

Evaluation of joint cartilage thickness in healthy children by ultrasound: An experience from a developing nation

OBJECTIVES

Musculoskeletal ultrasound (MSUS) has a crucial role in clinical assessment and monitoring of patients with rheumatologic diseases. Early detection of joint cartilage destruction is difficult. MSUS is a cheap, noninvasive, nonhazardous bedside tool that can be used for detection of cartilage damage. We aimed to generate normative data of joint cartilage thickness of children in our population using this tool.

METHODS

Healthy children, aged between 2 and 12 years, not suffering from any joint disorders and not on any chronic medication were recruited. The thickness of joint cartilage at wrist, knee and ankle were measured by ultrasound as per European League Against Rheumatism standard scan criteria. The scans were done by a single observer.

RESULTS

Data of 409 children revealed median cartilage thickness at right wrist, knee and ankle joints as 2.20 (interquartile range [IQR] 1.60-3.00) mm, 2.40 (1.80-3.10) mm and 2.20 (1.80-3.00) mm, respectively. The right-left differences were not statistically significant except at the knee joint. Comparison between genders showed that boys had marginally thicker cartilage than girls at all three joints; this difference was statistically significant for the knee and ankle joints, but not at the wrist. Joint cartilage thickness showed a steady decline with age.

CONCLUSIONS

Measurement of joint cartilage thickness in children with MSUS and comparison with these normative values can help in better screening for joint-related disease in children.

Fibrosis imaging: Current concepts and future directions

Fibrosis plays an important role in many different pathologies. It results from tissue injury, chronic inflammation, autoimmune reactions and genetic alterations, and it is characterized by the excessive deposition of extracellular matrix components. Biopsies are routinely employed for fibrosis diagnosis, but they suffer from several drawbacks, including their invasive nature, sampling variability and limited spatial information. To overcome these limitations, multiple different imaging tools and technologies have been evaluated over the years, including X-ray imaging, computed tomography (CT), ultrasound (US), magnetic resonance imaging (MRI), positron emission tomography (PET) and single-photon emission computed tomography (SPECT). These modalities can provide anatomical, functional and molecular imaging information which is useful for fibrosis diagnosis and staging, and they may also hold potential for the longitudinal assessment of therapy responses. Here, we summarize the use of non-invasive imaging techniques for monitoring fibrosis in systemic autoimmune diseases, in parenchymal organs (such as liver, kidney, lung and heart), and in desmoplastic cancers. We also discuss how imaging biomarkers can be integrated in (pre-) clinical research to individualize and improve anti-fibrotic therapies.

Microflow imaging: New Doppler technology to detect low-grade inflammation in patients with arthritis

Aim

To assess the efficacy of microvascular imaging in detecting low-grade inflammation in arthritis compared with Power Doppler ultrasound (PDUS).

Method and materials

Patients presenting for ultrasound with arthralgia were assessed with grey-scale, PDUS and Superb Microvascular Imaging (SMI). Videoclips were stored for analysis at a later date. Three musculoskeletal radiologists scored grey-scale changes, signal on PDUS and/or SMI within these joints. If a signal was detected on both PDUS and SMI, the readers graded the conspicuity of vascular signal from the two Doppler techniques using a visual analogue scale.

Results

Eighty-three patients were recruited with 134 small joints assessed. Eighty-nine of these demonstrated vascular flow with both PD and SMI, whilst in five no flow was detected. In 40 joints, vascularity was detected with SMI but not with PDUS (p = 0.007). Out of the 89 joints with vascularity on both SMI and PDUS, 23 were rated as being equal; while SMI scored moderately or markedly better in 45 cases (p <0.001).

Conclusion

SMI is a new Doppler technique that increases conspicuity of Doppler vascularity in symptomatic joints when compared to PDUS. This allows detection of low grade inflammation not visualised with Power Doppler in patients with arthritis.

Key Points

• SMI detects vascularity with improved resolution and sensitivity compared to Power Doppler.

• SMI can detect low-grade inflammation not seen with Power Doppler.

• Earlier detection of active inflammation could have significant impact on treatment paradigms.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-017-5016-4) contains supplementary material, which is available to authorized users.

Joint Involvement in Children with Celiac Disease

OBJECTIVE

To determine early joint involvement as detected by ultrasonography in children with newly diagnosed celiac disease, and in children with celiac disease on gluten-free diet for more than 6 months.

METHODS

Cross-sectional comparative study evaluating joint abnormalities by ultrasonography.

Results

Ultrasonography showed abnormalities in 19 out of 60 (31.7%) children with newly diagnosed celiac disease as compared to 2 (3.3%) out of 60 in those on a gluten-free diet for more than 6 months.

CONCLUSION

Subclinical synovitis as detected by ultrasound is a frequent finding in newly diagnosed children with celiac disease.

Strongly positive anti-CCP antibodies in patients with sacroiliitis or reactive arthritis post-E. coli infection: A mini case-series based review

We report here on four cases of patients with strongly positive anti-citrullinated cyclic peptides (anti-CCP) antibodies and clinical features of seronegative spondyloarthritis (SpA) and reactive arthritis. The four patients had various clinical presentations: one had an initial diagnosis of seropositive rheumatoid arthritis (RA) with involvement of the sacroiliac joints (similar to previous reports of the association of two diseases); one had a clinical picture of reactive arthritis following an episode of an Escherichia coli positive urinary tract infection; and two had asymmetrical sacroiliitis (SII), but no evidence of peripheral joint involvement (never reported before). In all cases, high titers of anti-CCP antibodies were found. We present a comparison of the clinical manifestations, radiographic features and treatment regimens of these cases. Our report supports previous literature data of possible overlap existing between RA and SpA, but also presents for the first time the association of high titers of anti-CCP antibodies with SII and reactive arthritis in patients with no peripheral small joint involvement.

Assessment of both articular synovitis and tenosynovitis by ultrasound is useful for evaluations of hand dysfunction in early rheumatoid arthritis patients

OBJECTIVES

We investigated the association between hand dysfunction and ultrasound (US)-detected articular synovitis and tenosynovitis in patients with rheumatoid arthritis (RA).

METHODS

Thirty RA patients were examined. In both hands of all subjects, articular synovitis and tenosynovitis were assessed by US at 22 joints and 12 tendons. Each joint and tendon was scored by gray-scale (GS) and power Doppler (PD) on a scale from 0 to 3. The sums of the GS or PD scores were used as the articular synovitis score and the tenosynovitis score. The sum of the articular synovitis and tenosynovitis scores was used as the combined US score. Hand dysfunction was evaluated by a grip-Health Assessment Questionnaire (HAQ) and visual analog scale of morning stiffness (MS-VAS). We used Spearman's correlation coefficient to determine the relationships among the US scores, the two hand dysfunction indices, and the DAS28-ESR.

RESULTS

The articular synovitis scores were significantly correlated with grip-HAQ (GS: r_s = 0.47, p = 0.009, PD: r_s = 0.48, p = 0.006), but not with MS-VAS. The tenosynovitis scores were correlated with MS-VAS (GS: r_s = 0.38, p = 0.039, PD: r_s = 0.36, p = 0.053), but not with grip-HAQ. Both grip-HAQ (GS: r_s = 0.53, p = 0.002, PD: r_s = 0.55, p = 0.001) and the MS-VAS (GS: r_s = 0.39, p = 0.031, PD: r_s = 0.47, p = 0.008) were correlated with the combined US scores.

CONCLUSIONS

The US scores combined with articular synovitis and tenosynovitis scores well reflect the severity of hand dysfunction in early-stage RA patients.

Advanced Imaging in Osteoarthritis

Context:

Radiography is widely accepted as the gold standard for diagnosing osteoarthritis (OA), but it has limitations when assessing early stage OA and monitoring progression. While there are improvements in the treatment of OA, the challenge is early recognition.

Evidence Acquisition:

MEDLINE and PubMed as well as professional orthopaedic and imaging websites were reviewed from 2006 to 2016.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

Magnetic resonance imaging (MRI) can provide the most comprehensive assessment of joint injury and OA with the advantages of being noninvasive and multiplanar with excellent soft tissue contrast. However, MRI is expensive, time consuming, and not widely used for monitoring OA clinically. Computed tomography (CT) and CT arthrography (CTA) can also be used to evaluate OA, but these are also invasive and require radiation exposure. Ultrasound is particularly useful for evaluation of synovitis but not for progression of OA.

Conclusion:

MRI, CT, and CTA are available for the diagnosis and monitoring of OA. Improvement in techniques and decrease in cost can allow some of these modalities to be effective methods of detecting early OA.

Advances and challenges in hemophilic arthropathy

Hemophilic arthropathy is a form of joint disease that develops secondary to joint bleeding and presents with synovial hypertrophy, cartilage and bony destruction. The arthropathy can develop despite clotting factor replacement and is especially disabling in the aging population. Pathobiological tissue changes are triggered by release of hemoglobin and iron deposition in the joint, but the sequence of events and the molecular mechanisms resulting in joint deterioration are incompletely understood. Treatment options other than clotting factor replacement are limited. Improvements in the treatment of hemophilia necessitate a better understanding of the processes that lead to this disabling condition and better diagnostic tools. Towards that end, studies of the molecular mechanisms leading to the arthropathy, as well as the development of sensitive imaging techniques and biomarkers are needed. These will pave the way to identify the cause of acute pain such as joint bleeding or synovitis, detect early, potentially reversible structural changes, and predict progression of disease. This review describes current imaging techniques and the development of high resolution musculoskeletal ultrasound with power Doppler to afford point-of-care diagnosis and management, the potential utility of diagnostic biomarkers, and summarizes our current knowledge of the pathobiology of hemophilic arthropathy.

Near infrared fluorescence imaging for early detection, monitoring and improved intervention of diseases involving the joint

Joints consist of different tissues, such as bone, cartilage and synovium, which are at risk for multiple diseases. The current imaging modalities, such as magnetic resonance imaging, Doppler ultrasound, X-ray, computed tomography and arthroscopy, lack the ability to detect disease activity before the onset of anatomical and significant irreversible damage. Optical in vivo imaging has recently been introduced as a novel imaging tool to study the joint and has the potential to image all kinds of biological processes. This tool is already exploited in (pre)clinical studies of rheumatoid arthritis, osteoarthritis and cancer. The technique uses fluorescent dyes conjugated to targeting moieties that recognize biomarkers of the disease. This review will focus on these new imaging techniques and especially where Near Infrared (NIR) fluorescence imaging has been used to visualize diseases of the joint. NIR fluorescent imaging is a promising technique which will soon complement established radiological, ultrasound and MRI imaging in the clinical management of patients with respect to early disease detection, monitoring and improved intervention.

Quantifying synovial inflammation: Emerging imaging techniques

Imaging techniques to assess synovial inflammation includes radiography, ultrasound, computed tomography, magnetic resonance imaging (MRI) and recently positron emission tomography. The ideal objective of imaging approaches are to quantify synovial inflammation by capturing features such as synovial hyperplasia, neo-angiogenesis and infiltration of immune cells in the synovium. This may enable clinicians to estimate response to therapy by measuring the improvement in the inflammatory signals at the level of synovium. Ultrasound can provide information regarding thickening of the synovial membrane and can reveal increased synovial blood flow using power Doppler technique. Bone marrow edema and synovial membrane thickness on MRI scan may serve as indicators for arthritis progression. Enhancement of the synovium on dynamic contrast MRI may closely mirror the inflammatory activity in the synovium. Diffusion tensor imaging is an advance MRI approach that evaluates the inflammation related to cell infiltration or aggregation in an inflamed synovium. In this review, we summarize the newer imaging techniques and their developments to evaluate synovial inflammation.

Musculoskeletal ultrasound in rheumatology in Korea: targeted ultrasound initiative survey

AIM

In collaboration with the Targeted Ultrasound Initiative (TUI), to conduct the first study in Korea to investigate current practices in ultrasound use among Korean rheumatologists.

METHODS

We translated the TUI Global Survey into Korean and added questions to better understand the specific challenges facing rheumatologists in Korea. To target as many rheumatologists in Korea as possible, we created an on-line version of this survey, which was conducted from March to April 2013.

RESULTS

Rheumatologists are in charge of ultrasound in many Korean hospitals. Rheumatologists in hospitals and private clinics use ultrasound to examine between one and five patients daily; they use ultrasound for diagnosis more than monitoring and receive compensation of about US$30-50 per patient. There are marked differences in the rates of ultrasound usage between rheumatologists who work in private practice compared with tertiary hospitals. Korean rheumatologists not currently using ultrasound in their practice appear eager to do so.

CONCLUSION

This survey provides important insights into the current status of ultrasound in rheumatology in Korea and highlights several priorities; specifically, greater provision of formal training, standardization of reporting and accrual of greater experience among ultrasound users. If these needs are addressed, all rheumatology departments in Korea are likely to use ultrasound or have access to it in the future.

Synovial pathology detected on ultrasound correlates with the severity of radiographic knee osteoarthritis more than with symptoms

OBJECTIVE

To [1] compare the frequency and severity of ultrasound (US) features in people with normal knees (controls), knee pain (KP), asymptomatic radiographic OA (ROA), and symptomatic OA (SROA), [2] examine relationships between US features, pain and radiographic severity, [3] explore the relationship between change in pain and US features over a 3-month period.

METHOD

Community participants were recruited into a multiple group case-control study. All underwent assessment for pain, knee radiographs and US examination for effusion, synovial hypertrophy, popliteal cysts and power Doppler (PD) signal within the synovium. A 3-month follow-up was undertaken in over half of control and SROA participants.

RESULTS

243 participants were recruited (90 controls; 59 KP; 32 ROA; 62 SROA). Effusion and synovial hypertrophy were more common in ROA and SROA participants. Severity of effusion and synovial hypertrophy were greater in SROA compared to ROA (P < 0.05). Severity of US effusion and synovial hypertrophy were correlated with radiographic severity (r = 0.6 and r = 0.7, P < 0.01) but the relationship between pain severity and US features was weak (r = 0.3, P < 0.01). In SROA participants, pain severity did not change in tandem with a change in synovial hypertrophy over time.

CONCLUSION

US abnormalities are common in OA. Effusion and synovial hypertrophy were moderately correlated with radiographic severity but the relationship with pain is less strong. The degree to which these features reflect "active inflammation" is questionable and they may be better considered as part of the total organ pathology in OA. Further studies are warranted to confirm these findings.

Plasma IL-6 levels correlate with clinical and ultrasound measures of arthritis in patients with systemic lupus erythematosus

OBJECTIVE

The objective of this paper is to elucidate the role of specific cytokines in lupus (SLE) arthritis.

METHODS

Fifty SLE and 40 RA patients had an ultrasound (US) scan of their hand as per standardized protocols. US scores were expressed per joint and as a total 'US activity' score, (sum of power Doppler (PD) and grey-scale synovial hypertrophy scores in all joints) and a total erosion score. SLE disease activity was assessed (BILAG and SELENA-SLEDAI). Plasma levels of IL-6, TNF-alpha and BLyS were measured using sandwich ELISA kits (Quantikine kits, R & D).

RESULTS

On the basis of the US results SLE patients were divided into three groups: erosive arthritis (n = 20), non-erosive arthritis (n = 18) and those with a normal US scan (n = 12). Across the SLE groups plasma IL-6 levels correlated with CRP (p < 0.001), hand deformity scores (p = 0.005), BILAG musculoskeletal score (p = 0.009), wrist PD score (p = 0.01), the presence of tenosynovitis (p = 0.008) and total US activity score (p < 0.001) (which remained constant when corrected for total BILAG score). Neither TNF-alpha nor BLyS levels correlated with US or clinical measures of lupus arthritis; however, TNF-alpha correlated with total BILAG score (p < 0.001).

CONCLUSION

This is the first study to examine levels of specific cytokines in a cohort of SLE patients stratified in terms of joint disease by US, where the most significant finding is that IL-6 levels correlated both with clinical and US measures of arthritis disease activity.

Rapid musculoskeletal ultrasound for painful episodes in adult haemophilia patients

Little objective information exists about musculoskeletal bleeding patterns in haemophilic arthropathy. Bleeding is assumed to be the cause of painful joints or muscles. Clotting factor treatment is provided empirically, but often does not alleviate pain. We hypothesized that perception of pain aetiology is unreliable, and introduced point-of-care high-resolution musculoskeletal ultrasound (MSKUS) to differentiate intra-articular bleeds vs. joint inflammation, and intra-muscle bleeds vs. other regional pain syndromes. To assess painful musculoskeletal episodes in adult haemophiliacs, we used rapid MSKUS, employing grey scale and power Doppler examination. Forty episodes in 30 adult haemophiliacs were evaluated. Thirty three of the 40 episodes were patient-reported as 'bleeding', five as 'arthritis-type' pain and two as 'undecided'. Of the 33 bleeding reports, only 12 were confirmed by MSKUS; the other episodes revealed other pathology. In contrast, three of five perceived arthritis flares were reclassified as bleeds. Similarly, physician assessment was incorrect in 18 of 40 instances. Swelling and warmth were present in approximately half of confirmed bleeding and non-bleeding episodes, and therefore not useful clinically. Few of the painful episodes were symptom controlled at the time of MSKUS. Management changed based on objective imaging findings in >70% of episodes, which resulted in symptom improvement >60% of the time. Significant discrepancies exist between MSKUS findings and patient/physician-perceived pain classification as bleeding or other musculoskeletal symptoms. Current practice of prescribing clotting factor or conservative measures based on pain perception seems inadequate and suggests that point-of-care imaging should be included into modern haemophilia care.