Magnetic resonance imaging of hindfoot involvement in patients with spondyloarthritides: comparison of low-field and high-field strength units

Magnetic resonance imaging characteristics in patients with spondyloarthritis and clinical diagnosis of heel enthesitis: post hoc analysis from the phase 3 ACHILLES trial

Objective

To investigate the imaging characteristics and clinically assess heel enthesitis in spondyloarthritis (SpA) by applying in a post hoc analysis the Heel Enthesitis Magnetic Resonance Imaging Scoring system (HEMRIS) in blinded and centrally-read MRI data from the ACHILLES trial (NCT02771210).

Methods

ACHILLES included patients (≥18 years) with active psoriatic arthritis or axial SpA with clinical and MRI-positive heel enthesitis refractory to standard treatment. Patients were randomized to receive subcutaneous secukinumab 150/300 mg or placebo. At week 24, patients on placebo were switched to secukinumab treatment. MRI-positive heel enthesitis was confirmed in all patients by local investigators. MRIs were performed at 3 timepoints: screening and weeks 24 and 52. In the present analysis, all MRIs were re-evaluated by 2 blinded central readers in a consensus read fashion for a priori defined MRI parameters based on HEMRIS.

Results

At screening, 171/204 (83.8%) of patients presented with entheseal inflammation and/or structural damage, considering both the Achilles tendon and plantar fascia. Pathologies were more evident in the Achilles tendon area compared to the plantar aponeurosis. The most frequent pathologies were intra-tendon hypersignal and retrocalcaneal bursitis. The mean total entheseal inflammation score at screening in the Achilles tendon area was 2.99 (N=204) and the mean change (standard deviation [SD]) from screening to weeks 24 and 52 was − 0.91 (1.99) and − 0.83 (2.12) in the secukinumab group vs − 0.48 (1.86) and − 0.80 (1.98) in the placebo-secukinumab group, respectively. The mean total structural damage score at screening was 1.36 (N=204) and the mean change (SD) from screening to weeks 24 and 52 was 0.00 (0.65) and − 0.06 (0.56) in the secukinumab group vs 0.08 (0.48) and 0.04 (0.75) in the placebo-secukinumab group, respectively.

Conclusions

Based on the newly developed HEMRIS, entheseal inflammation and/or structural damage was confirmed in 83.3% of ACHILLES patients. Pathologies were more evident in the Achilles tendon area compared to plantar fascia, with the inflammatory parameters being more responsive with secukinumab treatment compared to placebo. The present analysis, with detailed information on individual MRI parameters, contributes to the scientific debate on heel enthesitis.

Trial registration

ClinicalTrials.gov NCT02771210.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02797-8.

The Vienna morphological Achilles tendon score-VIMATS : Description, reproducibility and initial clinical results

OBJECTIVE

The purpose was to introduce the Vienna morphological Achilles tendon score (VIMATS), to evaluate its reproducibility and to assess its clinical application.

METHODS

In 38 patients a total number of 40 painful ATs and 20 volunteers were examined on a 3T magnetic resonance imaging (MRI) scanner using a standard MRI protocol. In 20 patients clinical scoring according to the Achilles tendon rupture score was available. Two observers independently assessed the thickness, continuity, signal intensity, and associated pathologies of the Achilles tendon (AT) according to the newly created VIMATS. Intraobserver and interobserver agreements were calculated and the clinical application of the VIMATS regarding its potential to differentiate between patients and volunteers was tested.

RESULTS

An analysis of the Intraclass correlation coefficient (ICC) yielded an excellent intraobserver (ICC 0.925) and interobserver agreement (ICC 0.946) for the total VIMAT score. A significant difference in total VIMATS was found between patients (47.6 ± StD 21.1 points) and volunteers (91.5 ± SD 10.9 points; p < 0.01) as well as a moderate correlation between morphological and clinical scoring (Pearson correlation 0.644).

CONCLUSION

The VIMAT score is the first MRI score for the semiquantitative morphological evaluation of AT injuries and was shown to be an easy, fast and reproducible tool for assessing injuries of the AT.

Magnetic Resonance Imaging of Enthesitis in Spondyloarthritis, Including Psoriatic Arthritis-Status and Recent Advances

Enthesitis, inflammation at the attachment sites of tendons, ligaments, fascia, and joint capsules to bones plays a critical role in the pathogenesis of spondyloarthritis (SpA), including psoriatic arthritis (PsA). Magnetic resonance imaging (MRI) has aided in a better understanding of pathophysiology, early diagnosis, prognostication, therapeutic outcomes, and follow up of enthesitis. The concept of enthesitis as a focal insertional pathology has transformed over the past decade, with the help of MRI, to a more widespread entity involving both bone and surrounding soft tissues. The utility of MRI in the differential diagnosis of suspected enthesitis has recently been explored. With the emergence of the treat-to-target concept, and a domain-based approach in the management of SpA, objective and sensitive monitoring of response to targeted therapy becomes prudent. Properties like high sensitivity, ability to image intra-osseous pathology along with surrounding structures exemplify the utility of MRI technology. Considering the lack of a comprehensive, validated MRI score the Outcome Measures in Rheumatology (OMERACT) MRI in Arthritis Working Group, informed by a systematic literature review, developed the first international, consensus-based MRI-scoring system, combined with MRI definitions of pathologies for enthesitis in patients with spondyloarthritis (SpA) and PsA. An atlas with representative images of each grade of the scoring system was subsequently developed by the group to aid readers interested in using the heel enthesitis MRI scoring system (HEMRIS). The HEMRIS can find utility in clinical trials targeting enthesitis as the primary outcome. MRI also finds value for global assessment of the total burden of enthesitis. The concept of whole-body MRI (WBMRI), enabling visualization of entheses throughout the body using a single image is relatively new. The MRI whole-body score for inflammation in peripheral joints and entheses (MRI-WIPE) is a promising scoring system, which is undergoing further testing in clinical trials and longitudinal cohorts evaluating global measures of inflammation at entheses. This review discusses the role of MRI in diagnosis and monitoring of enthesitis in SpA and PsA, along with recent advances in the field, based on published literature.

Utility of Magnetic Resonance Imaging in Diagnosis and Monitoring Enthesitis in Patients with Spondyloarthritis: An OMERACT Systematic Literature Review

Objective.

A systematic literature review was performed to document published magnetic resonance imaging (MRI) lesion definitions and scoring systems for enthesitis in spondyloarthritis (SpA).

Methods.

PubMed, Embase, and Cochrane Library databases were searched for original publications involving adult patients with SpA undergoing MRI of axial/peripheral joints. Selected articles were assessed for quality using a standardized assessment tool and metric indices.

Results.

Considering the heterogeneous design, quality, and outcome measures of studies, statistical data pooling was considered inappropriate. A qualitative narrative of results was undertaken based on study designs.

Conclusion.

Lack of a comprehensive, validated score warrants additional research to develop an MRI enthesitis scoring system. PROSPERO registration number: CRD42018090537.

Near-infrared Fluorescence Optical Imaging in Early Rheumatoid Arthritis: A Comparison to Magnetic Resonance Imaging and Ultrasonography

OBJECTIVE

Near-infrared fluorescence optical imaging (FOI) is a novel imaging technology in the detection and evaluation of different arthritides. FOI was validated in comparison to magnetic resonance imaging (MRI), greyscale ultrasonography (GSUS), and power Doppler ultrasonography (PDUS) in patients with early rheumatoid arthritis (RA).

METHODS

Hands of 31 patients with early RA were examined by FOI, MRI, and US. In each modality, synovitis of the wrist, metacarpophalangeal joints (MCP) 2-5, and proximal interphalangeal joints (PIP) 2-5 were scored on a 4-point scale (0-3). Sensitivity and specificity of FOI were analyzed in comparison to MRI and US as reference methods, differentiating between 3 phases of FOI enhancement (P1-3). Intraclass correlation coefficients (ICC) were calculated to evaluate the agreement of FOI with MRI and US.

RESULTS

A total of 279 joints (31 wrists, 124 MCP and 124 PIP joints) were evaluated. With MRI as the reference method, overall sensitivity/specificity of FOI was 0.81/0.00, 0.49/0.84, and 0.86/0.38 for wrist, MCP, and PIP joints, respectively. Under application of PDUS as reference, sensitivity was even higher, while specificity turned out to be low, except for MCP joints (0.88/0.15, 0.81/0.76, and 1.00/0.27, respectively). P2 appears to be the most sensitive FOI phase, while P1 showed the highest specificity. The best agreement of FOI was shown for PDUS, especially with regard to MCP and PIP joints (ICC of 0.57 and 0.53, respectively), while correlation with MRI was slightly lower.

CONCLUSION

FOI remains an interesting diagnostic tool for patients with early RA, although this study revealed limitations concerning the detection of synovitis. Further research is needed to evaluate its full diagnostic potential in rheumatic diseases.

[Imaging modalities in psoriatic arthritis]

This review presents an overview of the range of imaging modalities used in the diagnostic evaluation of patients with psoriatic arthritis (PsA). Conventional radiography is used to detect structural changes of the joints and tendon attachments. These changes occur late in the course of PsA hence conventional radiography contributes little to the early detection of PsA; however, the detection of periosteal proliferations on radiographs allows a relatively specific diagnosis of PsA. Skeletal scintigraphy and computed tomography are rarely used in PsA. Arthrosonography (ultrasound of the joints) is gaining increasing importance in the early identification of inflammatory soft tissue signs of PsA in the peripheral joints. Sonography enables early detection of synovitis and tenosynovitis as well as superficial erosions and also inflammatory processes of the tendon attachments. Magnetic resonance imaging (MRI) is indispensable for identifying possible involvement of the axial skeleton. Moreover, it allows good visualization of periostitis and arthritis. High resolution microcomputed tomography is an interesting novel diagnostic tool which allows highly sensitive evaluation of the bone structure and can detect very tiny bone lesions where typical signs of PsA are omega-shaped erosions and small corona-like spikes. Another interesting new diagnostic technique is fluorescence optical imaging (FOI) with the Xiralite system which is highly sensitive for detecting inflammatory processes of the hands.

Quantitative MRI measurements of the Achilles tendon in spondyloarthritis using ultrashort echo times

OBJECTIVES

Tendon involvement is common in spondyloarthritis. The MRI signal from the Achilles tendon has been used to quantify mechanical tendinopathy; however, conventional MRI is limited by the short T(2) of normal tendon. Short and ultrashort echo time (UTE) MRI have the potential to better measure signal intensity reflecting changes in T(2) or gadolinium enhancement. Furthermore, UTE images could be used for normalisation to reduce variability. The aim of this work was to investigate such techniques in patients with spondyloarthritis (SpA).

METHODS

The Achilles tendons of 14 healthy volunteers and 24 patients with symptomatic spondyloarthritis were studied. Combined UTE (TE=0.07 ms) and gradient echo (TE=4.9 ms) images were acquired before and after intravenous gadolinium together with pre-contrast gradient echo images (TE=2 ms). The signal intensity from a region of interest in the Achilles tendon above the calcaneus was measured. The relative enhancement at echo times of 0.07 ms (RE(0.1)) and 4.9 ms (RE(5)) were calculated. The ratios of the signal intensities from both 4.9 ms and 2 ms gradient echo images to the signal intensity from the UTE image were calculated (RTE(5) and RTE(2) respectively).

RESULTS

Interobserver intraclass correlation coefficients were excellent (≥0.97). The contrast-to-noise ratio was higher for enhancement on UTE images than on gradient echo images. RE(0.1), RTE(5) and RTE(2) were significantly higher in SpA patients than controls.

CONCLUSION

Signal intensity ratios using UTE images allow quantitative measurements to be made which are sensitive to tendon T(2) or contrast enhancement and which are increased in spondyloarthritis. They therefore have the potential for use as measures of tendon disease in spondyloarthritis.

The use of ultrasound for the assessment of enthesitis in patients with spondyloarthritis

Seronegative spondyloarthritis (SpA) represents a group of diseases that share certain genetic, clinical, and radiographic features. Enthesitis, inflammation at the site of tendon insertion into the bone, involving both the axial and the peripheral joints, is an important sign of SpA. Clinical diagnosis of enthesitis, however, is neither sensitive nor specific; thus, the diagnosis of enthesitis often relies on typical abnormalities in imaging studies. Due to its low costs and availability, ultrasound is emerging as the preferred technique for detection of enthesitis for both clinical and research purposes. Ultrasonographic features of enthesitis include tendon hypoechogenicity and thickening, calcifications, bone erosions, and Doppler signal. Several semi-quantitative scoring systems have been developed to quantify ultrasonographic abnormalities of the entheses. These methods have been used for early diagnosis and classification of SpA as well as for monitoring response to treatment.

Diagnosis of plantar plate injury by magnetic resonance imaging with reference to intraoperative findings

The objective of the present study was to assess the utility of magnetic resonance imaging in evaluating injury to the plantar plate and to determine whether conventional low-field magnetic resonance imaging is a valid tool for diagnostic evaluation. Magnetic resonance imaging scans of 45 feet in 41 patients (38 females and 3 males, with an average age of 52.1 years) were prospectively evaluated to assess the integrity of the plantar plate ligament and compared with a reference standard of intraoperative findings. The concordance of tear severity observed on magnetic resonance imaging with the intraoperative findings was also assessed using a newly proposed grading scheme for plantar plate injuries. Intraoperatively, 41 plantar plate tears and 4 intact ligaments were found. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value was 96%, 95%, 100%, 100%, and 67%, respectively. The clinical diagnosis of plantar plate injury was also highly accurate in our study population (41/45, 91%). Finally, we observed moderate concordance between the magnetic resonance imaging grade and surgical grade of plantar plate tear (28/45, 62%), with greater concordance occurring at higher grades. Our results have demonstrated that magnetic resonance imaging is an accurate and valid test for the diagnosing injuries of the plantar plate ligament. Given the high accuracy of the clinical findings, magnetic resonance imaging is most useful when the decision to operate will be sufficiently influenced by either a normal magnetic resonance imaging appearance of the plantar plate or the presence of a high-grade tear.

Tendon and ligament imaging

MRI and ultrasound are now widely used for the assessment of tendon and ligament abnormalities. Healthy tendons and ligaments contain high levels of collagen with a structured orientation, which gives rise to their characteristic normal imaging appearances as well as causing particular imaging artefacts. Changes to ligaments and tendons as a result of disease and injury can be demonstrated using both ultrasound and MRI. These have been validated against surgical and histological findings. Novel imaging techniques are being developed that may improve the ability of MRI and ultrasound to assess tendon and ligament disease.

Comparison of two ultrashort echo time sequences for the quantification of T1 within phantom and human Achilles tendon at 3 T

Ultrashort echo time (UTE) techniques enable direct imaging of musculoskeletal tissues with short T2 allowing measurement of T1 relaxation times. This article presents comparison of optimized 3D variable flip angle UTE (VFA-UTE) and 2D saturation recovery UTE (SR-UTE) sequences to quantify T1 in agar phantoms and human Achilles tendon. Achilles tendon T1 values for asymptomatic volunteers were compared to Achilles tendon T1 values calculated from patients with clinical diagnoses of spondyloarthritis (SpA) and Achilles tendinopathy using an optimized VFA-UTE sequence. T1 values from phantom data for VFA- and SR-UTE compare well against calculated T1 values from an assumed gold standard inversion recovery spin echo sequence. Mean T1 values in asymptomatic Achilles tendon were found to be 725±42 ms and 698±54 ms for SR- and VFA-UTE, respectively. The patient group mean T1 value for Achilles tendon was found to be 957±173 ms (P<0.05) using an optimized VFA-UTE sequence with pulse repetition time of 6 ms and flip angles 4, 19, and 24°, taking a total 9 min acquisition time. The VFA-UTE technique appears clinically feasible for quantifying T1 in Achilles tendon. T1 measurements offer potential for detecting changes in Achilles tendon due to SpA without need for intravenous contrast agents.

Bone marrow lesions: a universal bone response to injury?

The ever increasing use of magnetic resonance imaging in clinical practice has led to the recognition of a new entity, bone marrow lesions (BMLs). These lesions are characterized by excessive water signals in the marrow space and have emerged as a central component of many different diseases affecting the musculoskeletal system. BMLs have in particular been associated with a wide variety of inflammatory and non-inflammatory rheumatologic conditions and are not only considered significant sources of pain, but also linked to the worsening of patient prognosis in many disease states. In this review, we summarize the current knowledge on BMLs with an emphasis on the clinical and histological features of this entity in inflammatory and non-inflammatory disease and provide a unifying hypothesis based on the appearance with various imaging technologies. We also try to pair this hypothesis with the apparent beneficial effects of various treatment regimens, mainly within the group of bone antiresorptive drugs (calcitonin, bisphosphonates) on symptoms associated with BMLs.

Imaging of the Achilles tendon in spondyloarthritis: a comparison of ultrasound and conventional, short and ultrashort echo time MRI with and without intravenous contrast

OBJECTIVES

To compare conventional MRI, ultrashort echo time MRI and ultrasound for assessing the extent of tendon abnormalities in spondyloarthritis.

METHODS

25 patients with spondyloarthritis and Achilles symptoms were studied with MRI and ultrasound. MR images of the Achilles tendon were acquired using T1-weighted spin echo, gradient echo and ultrashort echo time (UTE) sequences with echo times (TE) between 0.07 and 16 ms, before and after intravenous contrast medium. Greyscale and power Doppler ultrasound were also performed. The craniocaudal extent of imaging abnormalities measured by a consultant musculoskeletal radiologist was compared between the different techniques.

RESULTS

Abnormalities were most extensive on spoiled gradient echo images with TE = 2 ms. Contrast enhancement after intravenous gadolinium was greatest on the UTE images (TE = 0.07 ms). Fewer abnormalities were demonstrated using unenhanced UTE. Abnormalities were more extensive on MRI than ultrasound. Contrast enhancement was more extensive than power Doppler signal.

CONCLUSIONS

3D spoiled gradient echo images with an echo time of 2 ms demonstrate more extensive tendon abnormalities than the other techniques in spondyloarthritis. Abnormalities of vascularity are best demonstrated on enhanced ultrashort echo time images.

MRI in juvenile idiopathic arthritis and juvenile dermatomyositis

The use of MRI in the assessment of the musculoskeletal system in children has important differences from its use in adults. Growth in children has significant impact on the epiphysis and growth plate, which are important structures in the growing child, and there are radiological features that differ from those in adults: disease may alter structures during a period of growth; the pathologies themselves are a distinct group of diseases at variance with adult arthritis and myositis, with a different spectrum of differential diagnoses; and many technical issues are different when imaging a child. These are important considerations in choosing the appropriate imaging. MRI is a powerful and valuable imaging technique in pediatric musculoskeletal pathologies, with considerable potential for future developments to enhance its role in diagnosis, management, and therapeutic intervention for these children.

Imaging of seronegative spondyloarthritis

Magnetic resonance imaging (MRI) and ultrasonography (US) are useful adjuncts in the diagnosis of seronegative spondyloarthritides (SpA); a group of diseases that present early at a stage when radiographic assessment is invariably normal. This chapter will review how MRI and US can be used in the evaluation of early SpA. The diffuse osteitis/enthesitis on MRI may serve as a diagnostic hallmark for SpA spinal disease, but needs confirmatory studies for comparison with other spinal pathologies. MRI is the modality of choice for monitoring axial disease in anti-tumour necrosis factor (TNF) therapy responses in the research environment, but it is not yet certain whether this will be relevant in clinical practice. Anti-TNF therapy may be associated with regression of MRI-determined osteitis, but retardation of associated bony fusion is debatable. MRI and US are still undergoing evaluation for the diagnosis of enthesitis of the appendicular skeleton; US, in particular, shows promise at these sites.

MRI of enthesitis of the appendicular skeleton in spondyloarthritis

Entheses are sites where tendons, ligaments, joint capsules or fascia attach to bone. Inflammation of the entheses (enthesitis) is a well-known hallmark of spondyloarthritis (SpA). As entheses are associated with adjacent, functionally related structures, the concepts of an enthesis organ and functional entheses have been proposed. This is important in interpreting imaging findings in entheseal-related diseases. Conventional radiographs and CT are able to depict the chronic changes associated with enthesitis but are of very limited use in early disease. In contrast, MRI is sensitive for detecting early signs of enthesitis and can evaluate both soft-tissue changes and intraosseous abnormalities of active enthesitis. It is therefore useful for the early diagnosis of enthesitis-related arthropathies and monitoring therapy. Current knowledge and typical MRI features of the most commonly involved entheses of the appendicular skeleton in patients with SpA are reviewed. The MRI appearances of inflammatory and degenerative enthesopathy are described. New options for imaging enthesitis, including whole-body MRI and high-resolution microscopy MRI, are briefly discussed.