Limits and perspectives of ultrasound in the diagnosis and management of rheumatic diseases

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.

SWE and SMI ultrasound techniques for monitoring needling treatment of ankylosing spondylitis: study protocol for a single-blinded randomized controlled trial

Background

Ankylosing spondylitis (AS) is a high-incidence disease in young men that interferes with patients’ physical and mental wellbeing and overall quality of life (QoL). It is often accompanied by arthralgia, stiffness, and limited lumbar flexibility. Acupuncture is safe and effective for reducing the symptoms of AS, but the underlying mechanisms by which it does so are not fully understood. Therefore, to objectively assess acupuncture efficacy, which is critical for patients making informed decisions about appropriate treatments, we will use shear-wave elastography (SWE) and superb microvascular imaging (SMI) ultrasound techniques to evaluate elasticity of lumbar paraspinal muscles and blood flow to the sacroiliac joint (SIJ) in AS.

Methods

We will recruit a total of 60 participants diagnosed with AS and 30 healthy subjects. Participants will be randomly allocated 1:1 to either an acupuncture group or a sham control acupuncture group. Primary-outcome measures will be musculoskeletal ultrasound, Ankylosing Spondylitis Quality of Life Scale (ASQoL), Bath Ankylosing Spondylitis Metrology Index (BASMI), and the Visual Analogue Scale (VAS) for pain. Secondary outcome measures will be the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Function Index (BASFI), and Fatigue Scale-14 (FS-14). We will monitor the effect of acupuncture or sham acupuncture on blood flow and SIJ inflammation using SMI, lumbar-muscle stiffness using SWE and the lumbar paraspinal-muscle cross-sectional area (CSA) using a two-dimensional (2D) grayscale imaging. QoL, physical function, and fatigue will be assessed using an evaluation scale or questionnaire developed for this study, with outcomes measured by the ASQoL, BASMI, BASDAI, BASFI, and FS-14. Healthy subjects will not receive acupuncture but undergo only musculoskeletal ultrasound at baseline. Acupuncture and sham control acupuncture interventions will be conducted for 30 min, 2–3 times/week for 12 weeks. Musculoskeletal ultrasound will be conducted at baseline and post-intervention, while other outcomes will be measured at baseline, 6 weeks, and post-intervention. The statistician, outcome assessor, and participants will be blinded to treatment allocation.

Discussion

The results of this single-blinded, randomized trial with sham controls could help demonstrate the efficacy of acupuncture and clarify whether musculoskeletal ultrasound could be used to evaluate AS.

Trial registration

ClinicalTrials.gov ChiCTR2000031476. Registered 3 April 2020.

Educational quality of YouTube videos on musculoskeletal ultrasound

Introduction/objectives

A progressively growing number of rheumatologists have integrated musculoskeletal ultrasound (MSUS) as a prized tool in their daily clinical practice over the past two decades. Lately, YouTube is often used by healthcare professionals as an educational tool. This study aimed to analyze the quality of educational information available on YouTube pertaining to MSUS.

Method

We performed a search using the keyword “musculoskeletal ultrasound” on YouTube in January 2021. Of the first 200 videos screened, 147 met the inclusion criteria. The quality and reliability of the videos were evaluated using the global quality score (GQS) and modified DISCERN score, and their popularity was assessed using the Video Power Index (VPI).

Results

Of the 147 videos evaluated, 58 (39.5%) were of high quality, 30 (20.4%) were of moderate quality, while 59 (40.1%) were of low quality. The modified DISCERN score and the duration of the videos were significantly higher in the high-quality videos than the moderate- and low-quality videos (p < 0.001 for all). The median number of views per day, likes, comments, and the popularity of the videos assessed with VPI were significantly higher in the high- and moderate-quality group compared to the low-quality videos (p < 0.001, p < 0.001, p = 0.007, and p < 0.001, respectively).

Conclusion

The quality of YouTube videos as an educational source on MSUS is unsatisfactory. Professional organizations and physicians should consider creating more high-quality MSUS videos. YouTube should consider filtering out poor-quality videos in collaboration with experts in the field.

Key Points • Although rheumatologists are increasingly using ultrasound as an extension of their exam, accessing musculoskeletal ultrasound training is still facing some challenges. • YouTube is commonly used as an educational source by medical students and healthcare professionals. • Approximately 60% of the videos related to musculoskeletal ultrasound on YouTube revealed high and moderate quality, while the remaining 40% were of low quality and not suitable for medical education. • A filtering mechanism is required to improve the quality of YouTube content on MSUS.

Beliefs, attitude, and knowledge of the Iranian physiatrists towards neuromusculoskeletal ultrasound and common barriers in its application

Background

Regarding the increasing application of neuromusculoskeletal sonography among medical specialties, specifically physiatrists, this study aims to assess the knowledge and skill level of these specialists in neuromusculoskeletal sonography in Iran.

Methods

This descriptive, cross-sectional study was performed in 2018. The utilized questionnaire developed based on previous studies in collaboration with 6 university lecturers of Shaheed Beheshti, Iran, and Tabriz medical universities and a physiatrist from Hacettepe University (Turkey); it included questions entailing demographic data, knowledge, and performance levels. Its validity and reliability were evaluated through face validation, pilot study, and the Cronbach α calculated via SPSS. Data extraction and analysis were also performed by SPSS-25.

Results

Of 364 questionnaires distributed, 300 were properly filled and entered into the study, of which, 38% were filled by clinical residents, 10% university lecturers, and 52% other categories (e.g. private sector).

The average number of musculoskeletal patient visits was 140.6 ± 119 and the mean number of musculoskeletal sonographies requested was 8.2 ± 5.2 per month (the three most common indications reported as the shoulder, carpal tunnel syndrome, and tendon injuries).

95% of the participants considered the importance of sonography for physiatrists to be “very high” or “high”; with the most valuable applications “as a guide for procedures (90%), its diagnostic utility (68%), and follow up/evaluating the response to treatment (45%). 86% of physiatrists reported they had participated in musculoskeletal sonography courses, 60% during residency, and the rest through workshops.

Also, the participants mentioned safety (83%), the possibility of performing simultaneous diagnosis and intervention procedures (70%), repeatability (58%), and dynamic imagery (52%) as the major advantages of musculoskeletal ultrasound.

Conclusion

a large number of doctors consider musculoskeletal sonography to be essential for physiatrists, though insufficient education on the subject and the low number of ultrasound devices are some of the obstacles in enhancing the use of this technology in PM&R setting. Presenting certified specific training courses during residency, provision of necessary rotations, using the capacities of the PM&R scientific committee, and the private sector for running workshops and professional training courses are suggested for enhancing the knowledge and skills of neuromusculoskeletal sonography.

The Dorsal 4-finger Technique: A Novel Method to Examine Metacarpophalangeal Joints in Patients with Rheumatoid Arthritis

OBJECTIVE

To describe the dorsal 4-finger technique (DFFT) in examining metacarpophalangeal (MCP) joints of patients with rheumatoid arthritis (RA) and compare it to the traditional 2-finger technique (TFT) using ultrasound (US) as a gold standard.

METHODS

Four rheumatologists evaluated 180 MCP joints of 18 patients with RA. All patients underwent US for greyscale (GSUS) and power Doppler US (PDUS). Agreements between rheumatologists, the 2 techniques, and US were evaluated using Cohen κ and the first-order agreement coefficient (AC1) κ methods.

RESULTS

The population comprised 17 females (94.4%) with a mean (SD) age and disease duration of 56.8 (14.4) and 21.8 (12.9) years, respectively. Eight patients (44.4%) were taking methotrexate monotherapy, while 10 patients (55.6%) were receiving biologics. US evaluation revealed 69 (38.3%) and 30 (16.7%) joints exhibited synovitis grade 2-3 by GSUS and PDUS, respectively. Effusion was documented in 30 joints (16.7%). The mean intraobserver agreement using the DFFT and TFT were 80.5% and 86%, respectively. The mean interobserver agreements using the DFFT and TFT were 84% and 74%, respectively. κ agreement with US findings was similar for both techniques in tender joints but was higher for the DFFT in nontender joints (0.33 vs 0.07, p = 0.015 for GSUS) and (0.48 vs 0.11, p = 0.002 for PDUS). The DFFT had a higher sensitivity in detecting ballottement by GSUS (0.47 vs 0.2, p < 0.001) and PDUS (0.60 vs 0.27, p < 0.001).

CONCLUSION

The DFFT is a novel, reproducible, and reliable method to examine MCP joints, and it has a better correlation with US than the traditional TFT.

Occult spondyloarthritis in inflammatory bowel disease

Spondyloarthritis (SpA) is a frequent extra-intestinal manifestation in patients with inflammatory bowel disease (IBD), although its real diffusion is commonly considered underestimated. Abnormalities in the microbioma and genetic predisposition have been implicated in the link between bowel and joint inflammation. Otherwise, up to date, pathogenetic mechanisms are still largely unknown and the exact influence of the bowel activity on rheumatic manifestations is not clearly explained. Due to evidence-based results of clinical studies, the interest on clinically asymptomatic SpA in IBD patients increased in the last few years. Actually, occult enthesitis and sacroiliitis are discovered in high percentages of IBD patients by different imaging techniques, mainly enthesis ultrasound (US) and sacroiliac joint X-ray examinations. Several diagnostic approaches and biomarkers have been proposed in an attempt to correctly classify and diagnose clinically occult joint manifestations and to define clusters of risk for patient screening, although definitive results are still lacking. The correct recognition of occult SpA in IBD requires an integrated multidisciplinary approach in order to identify common diagnostic and therapeutic strategies. The use of inexpensive and rapid imaging techniques, such as US and X-ray, should be routinely included in daily clinical practice and trials to correctly evaluate occult SpA, thus preventing future disability and worsening of quality of life in IBD patients.

A novel ultrasound technique for detection of osteochondral defects in the ankle joint: a parametric and feasibility study

(Osteo)chondral defects (OCDs) in the ankle are currently diagnosed with modalities that are not convenient to use in long-term follow-ups. Ultrasound (US) imaging, which is a cost-effective and non-invasive alternative, has limited ability to discriminate OCDs. We aim to develop a new diagnostic technique based on US wave propagation through the ankle joint. The presence of OCDs is identified when a US signal deviates from a reference signal associated with the healthy joint. The feasibility of the proposed technique is studied using experimentally-validated 2D finite-difference time-domain models of the ankle joint. The normalized maximum cross correlation of experiments and simulation was 0.97. Effects of variables relevant to the ankle joint, US transducers and OCDs were evaluated. Variations in joint space width and transducer orientation made noticeable alterations to the reference signal: normalized root mean square error ranged from 6.29% to 65.25% and from 19.59% to 8064.2%, respectively. The results suggest that the new technique could be used for detection of OCDs, if the effects of other parameters (i.e., parameters related to the ankle joint and US transducers) can be reduced.

Tibialis posterior tenosynovitis and associated pes plano valgus in rheumatoid arthritis: electromyography, multisegment foot kinematics, and ultrasound features

Objective

To compare electromyographic (EMG), kinematic, kinetic, and ultrasound (US) features of pes plano valgus associated with US-confirmed tibialis posterior (TP) tenosynovitis in rheumatoid arthritis (RA) and healthy control subjects.

Methods

In this cross-sectional study, patients with RA and US-confirmed tenosynovitis of TP underwent gait analysis, including 3-dimensional kinematics, kinetics, and intramuscular EMG of TP, and findings were compared with a group of healthy individuals. The RA group also underwent B mode and power Doppler US scanning of the TP tendon to assess and score levels of pathology.

Results

Ten patients with RA, median (range) disease duration of 3 years (1–18 years), and 5 control subjects were recruited. Compared to control subjects, the RA patients walked slower and presented with moderate levels of foot-related disability. The mean ± SD Disease Activity Score in 28 joints was 4.6 ± 1.6. Increased magnitude of TP activity was recorded in the RA group compared to controls in the contact period of stance (P = 0.007), in conjunction with reduced ankle joint power (P = 0.005), reduced navicular height in the medial arch (P = 0.023), and increased forefoot dorsiflexion (P = 0.027). TP tendon thickening, fluid, and power Doppler signal were observed in the majority of patients.

Conclusion

This study has demonstrated, for the first time, increased TP EMG activity in the presence of US-confirmed TP tenosynovitis in RA. Altered muscle function occurred in conjunction with suboptimal mechanics, moderate levels of tendon pathology, and active disease. Targeted therapy may be warranted to reduce inflammation and mechanically off-load diseased tendon states.

Ultrasound applications for the practicing rheumatologist

Musculoskeletal ultrasound is an increasingly used tool for the evaluation and management of rheumatologic diseases. Its utilisation by rheumatologists is varied around the world and is dependent upon training and local expertise. Its applications can be broadly categorised into three main areas; for the education of patients, to aid the rheumatologist in the diagnosis and monitoring of disease, and therapeutically for joint aspiration and injection. Ultrasound is a safe, portable, easily repeatable, dynamic images in multiple planes and cheap form of imaging. Ultrasound however, is operator dependent and has a number of artefacts that can result in misinterpretation. Musculoskeletal Ultrasound uses a number of modes to characterise joint pathology, including grey scale, colour and power Doppler, spectral Doppler, 3D imaging, elastography. Musculoskeletal ultrasound can detect and monitor multiple joint pathologies including synovitis, tenosynovitis, and tendon pathologies, entheseal processes, bone erosions and osteophytes, cartilage changes and bursal pathologies.

Imaging of polymyalgia rheumatica: indications on its pathogenesis, diagnosis and prognosis

OBJECTIVES

Imaging is one of the most appealing techniques to explore PMR, a disease whose causes, development mechanisms and anatomical targets of inflammatory damage are still scarcely known. This review is concerned with an appraisal of PMR with different imaging modalities with a view to highlighting possible clues to its pathogenesis, diagnosis and prognosis.

METHODS

A systematic literature research was performed searching PubMed until July 2010. The Cochrane Library was searched for the relevant reviews, and the abstracts of the ACR and European League Against Rheumatism congresses of the period 2005-10 were reviewed.

RESULTS

A total of 1059 papers were retrieved, 46 of which were selected at the end of the review process; 6 of them were concerned with two different imaging techniques. Of these papers, 6 (11.5%) were concerned with conventional radiology; 8 (15.4%) with scintigraphy; 17 (32.7%) with ultrasonography (US); 15 (28.8%) with MRI; and 6 (11.5%) with PET. MRI, US and PET appeared to be the most promising imaging techniques. Bilateral subacromial bursitis, biceps long head tenosynovitis and trochanteric bursitis were particularly consistent findings. In addition, MRI and PET showed interspinous bursitis and PET frequently showed large-vessel vasculitis. Few papers have addressed the role of imaging for diagnosis, differential diagnosis and prognosis of PMR.

CONCLUSIONS

Imaging plays an important role in the comprehensive evaluation of PMR, including its pathogenesis, diagnosis and prognosis. Most of its potential is still unexplored, which fact should stimulate further research.

Utility and feasibility of musculoskeletal ultrasonography (MSK US) in rheumatology practice in Canada: needs assessment

The utility of musculoskeletal ultrasound (MSK US) is being extensively explored and evaluated amongst European rheumatologists. However, utilization of MSK US by rheumatologists in Canada is much less common. This study aimed to evaluate the current use of MSK US in Canadian rheumatology practice, to determine beliefs and attitudes towards MSK US, and to determine factors that may encourage or limit its use. A 13-question needs assessment questionnaire was developed. All Canadian rheumatologists were invited via e-mail to participate in the survey. The overall response rate was 156/470 (33%). Fifty-one percent of participants used MSK US in their clinical practice. Lack of training appeared to be the main obstacle to its current use. Eighty-three percent believed that MSK US should be performed by rheumatologists and expressed a willingness to learn the technique. Skills offering greatest clinical utility were the assessment of inflammatory arthritis in small joints (i.e., hands (metacarpophalyngeal and proximal interphalangeal joints), wrists, feet (metatarsophalyngeal), shoulders, and ankles. Limited available time, equipment costs, and difficulties with billing were the main obstacles to MSK US utilization in the clinical setting. There is a great level of interest in learning and applying MSK US in Canadian rheumatology practice. The balance between added clinical value and lack of remuneration, equipment associated costs, and time to complete training is the major limiting factor influencing rheumatologists' willingness to take on MSK US. Training programs must be relevant to rheumatologists' needs before MSK US will be adopted into routine clinical practice in Canada.

Developments in musculoskeletal ultrasound and clinical applications

OBJECTIVE

Ultrasound (US) technologies are rapidly advancing, offering several refined transducer technologies as well as soft and hardware facilities. The aim of this article is to outline US developments, from B-mode technologies over Doppler advances to more sophisticated technologies, and their potential clinical impact in the field of musculoskeletal (MSK) imaging.

NEW ADVANCES

When using B-mode ultrasound, compound imaging and beam-steering are of help to decrease anisotropy in tendons and ligaments, that are less well depicted due to their oblique course. Doppler imaging has become sensitive in the detection of flow in small vessels, which is of particular value in rheumatologic conditions, tumour and overuse assessment. The use of US microbubble contrast agents improves detection of low-volume blood flow in smaller vessels by increasing the signal-to-noise ratio and thereby facilitating detection of angiogenetic vessels in inflammatory conditions or tumours. The use of US blood pool contrast agents enables molecular imaging in real-time, and thus the diagnostic potential of US is expanded, opening up a new field of US applications. Objective quantification of altered tissue (e.g., synovial proliferation, tumours) is still demanding and might be improved by the use of three-dimensional imaging and software tools as parametric evaluation. Real-time sonoelastography (EUS) is a new development for visualization of tissue elasticity by measurement of tissue displacement in terms of tissue stiffness changes, promising new insights into tendon disorders. Image fusion is an exciting development that enables superimposition of CT/MRI data sets on real-time US scanning. This technique might be helpful in guiding injections under real-time conditions even in regions less easily accessible by US as, for instance, the axial skeleton, and can additionally provide an interesting tool for teaching MSK imaging and ways to guide interventions.

CONCLUSION

In summary, exciting developments are expanding the applications of US in the MSK field, offering the advantages of real-time performance, high tissue resolution and relative speed at a reasonable cost.

Ultrasound of the hands and feet for rheumatological disorders: influence on clinical diagnostic confidence and patient management

PURPOSE

The purpose of the study was to quantify the impact that ultrasound (US) of the hands and feet has on the rheumatologists' diagnostic confidence and on patient management.

MATERIALS AND METHODS

There were 62 consecutive referrals from two rheumatologists for US of the hands and/or feet for this prospective controlled observational study. Measurements of diagnostic confidence for both specific clinical findings as well as overall diagnosis using a Likert scale were made both before and after the US examination in each case. Proposed management was also recorded before US and then with the benefit of the US result. McNemar's test was performed to determine differences in diagnostic certainty and proposed management before and after US.

RESULTS

The physician certainty for specific clinical findings increased significantly following US for synovitis (9.7 vs 38.7%), tenosynovitis (9.7 vs 46.8%), erosions (1.6 vs 58.1%), enthesitis (50.0 vs 83.9%) and other (53.2 vs 77.4%). The physician certainty for overall diagnosis increased significantly for seronegative arthritis (46.8 vs 61.3%), inflammatory osteoarthritis (46.8 vs 87.1%), and primary osteoarthritis (46.8 vs 73.0%). A total of 88.7% of patients had disease-modifying antirheumatic drugs as a proposed management option before US vs 48.4% after US. Before US, 4.8% of patients had non-steroidal anti-inflammatory drug as a proposed management option versus 45.2% after US.

CONCLUSION

Ultrasound of the hands and/or feet significantly influenced the rheumatologists' diagnostic confidence in specific clinical findings and management plans.