Whole-body MR imaging for patients with rheumatism

Advances in the Evaluation of Peripheral Enthesitis by Magnetic Resonance Imaging in Patients With Psoriatic Arthritis

Enthesitis is a key disease manifestation in patients with psoriatic arthritis (PsA) that considerably contributes to pain, lower physical function, and reduced quality of life. Clinical assessment of enthesitis lacks sensitivity and specificity, and therefore better methods are urgently needed. Magnetic resonance imaging (MRI) allows detailed assessment of the components of enthesitis, and consensus-based validated MRI scoring systems exist. These include the Outcome Measures in Rheumatology (OMERACT) Heel Enthesitis MRI Scoring System (HEMRIS) method, which assesses the entheses of the heel region in a detailed manner, and the OMERACT MRI Whole-Body Score for Inflammation in Peripheral Joints and Entheses (MRI-WIPE) method, which provides an overall assessment of the inflammatory burden in the peripheral entheses and joints in the entire body using whole-body MRI. At an MRI workshop at the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) 2022 meeting in Brooklyn, the MRI appearances of peripheral enthesitis were described, as were the scoring methods. The utility of MRI for improved assessment of enthesitis was demonstrated with examples of patient cases. Clinical trials in PsA that evaluate enthesitis by MRI as a key endpoint should include the presence of MRI enthesitis as an inclusion criterion, and apply validated MRI outcomes to assess the effect of therapeutics on enthesitis are recommended.

The role of whole-body MRI in musculoskeletal inflammation detection and treatment response evaluation in inflammatory arthritis across age: A systematic review

OBJECTIVE

To evaluate the relation between whole-body MRI (WBMRI) outcomes and disease activity measures, including clinical examination, composite scores, and other imaging outcomes, and the ability of WBMRI to detect treatment response in patients with inflammatory arthritis (IA) across age.

METHODS

Human studies published as full text or abstract in the PubMed and MEDLINE and Cochrane databases from inception to 11th April 2021 were systematically and independently searched by two reviewers. Studies including patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), spondyloarthritis (SpA), juvenile idiopathic arthritis (JIA) or unclassified inflammatory arthritis (UA) who underwent WBMRI and which reported on disease outcomes were included.

RESULTS

Nineteen full-text studies were eligible for inclusion: 2 interventional, 7 retrospective and 10 prospective observational studies, comprising 540 participants (SpA 38.7%, RA 24.8%, JIA 17.8%, PsA 11.5%, healthy controls 5.9%, UA 1.3%). Abstracts of 6 conference papers were reported separately. Five studies in PsA and SpA and 4 in RA measured the frequency of WBMRI-detected and clinically-detected synovitis, and all found the former to be more frequent. Less enthesitis was detected by WBMRI than clinical examination in 5/8 studies. After biologic treatment, the WBMRI inflammation scores declined in 3 studies in SpA and 2 in RA, whilst in 3 studies the results were equivocal.

CONCLUSION

The ability of WBMRI to assess disease activity and treatment response in IA was adequate overall. Further studies are needed to corroborate WBMRI findings with IA outcomes and investigate the clinical value of subclinical inflammation.

Consensus-driven conceptual development of a standardized whole body-MRI scoring system for assessment of disease activity in juvenile idiopathic arthritis: MRI in JIA OMERACT working group

OBJECTIVES

Whole body-MRI is helpful in directing diagnostic and treatment approaches, and as a research outcome measure. We describe our initial consensus-driven phase towards developing a whole body-MRI scoring system for juvenile idiopathic arthritis.

METHODS

An iterative approach using three rounds of anonymous Delphi surveys followed by a consensus meeting was used to draft the structure of the whole body-MRI scoring system, including the relevant anatomic joints and entheses for assessment, diagnostic item selection, definition and grading, and selection of appropriate MRI planes and sequences. The surveys were completed independently by an international expert group consisting of pediatric radiologists and rheumatologists.

RESULTS

Twenty-two experts participated in at least one of three rounds of Delphi surveys and a concluding consensus meeting. A first iteration scoring system was developed which ultimately included the assessment of 100 peripheral, 23 chest, and 76 axial joints, and 64 entheses, with 2-4 diagnostic items graded in each of the items, using binary (presence/absence) and 2-3-level ordinal scores. Recommendations on anatomic MRI planes and sequences were specified as the minimally necessary imaging protocol for the scoring system.

CONCLUSION

A novel whole body-MRI scoring system for juvenile idiopathic arthritis was developed by consensus among members of MRI in JIA OMERACT working group. Further iterative refinements, reliability testing, and responsiveness are warranted in upcoming studies.

Toward Developing a Semiquantitative Whole Body-MRI Scoring for Juvenile Idiopathic Arthritis: Critical Appraisal of the State of the Art, Challenges, and Opportunities

With powerful new therapies available for management of juvenile idiopathic arthritis (JIA), early diagnosis leading to appropriate treatment may prevent long-term structural joint damage. Although magnetic resonance imaging (MRI) is typically used to assess individual body parts, indications for whole body (WB) MRI are increasing. Its utility as a diagnostic and monitoring tool has already been widely investigated in adult rheumatology patients, but less so in pediatric rheumatologic patients. This paper is a comprehensive review of scoring systems and a proposal for the conceptual development of a WB-MRI scoring system for the evaluation of JIA. In this review we identify, summarize, and critically appraise the available literature on the use of WB-MRI in inflammatory arthritis, addressing relevant considerations on components of a classification system that can lead to the development of a future pediatric WB-MRI scoring system for use in children with JIA. We also discuss advantages and challenges of developing such a WB-MRI scoring system for assessment of JIA and outline next steps toward the conceptual development of this scoring system.

Quantitative Assessment of the Mandibular Condyle in Patients With Rheumatoid Arthritis Using Diffusion-Weighted Imaging

PURPOSE

The purpose of this study was to quantitatively assess the mandibular condyle in patients with rheumatoid arthritis (RA) using the apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI).

PATIENTS AND METHODS

Thirty-one patients with RA and temporomandibular joint (TMJ) pain who underwent magnetic resonance imaging (MRI) examination of the TMJs at our hospital between August 2006 and March 2020 were included in this study. Twenty-one patients with normal TMJs who underwent MRI examination at our hospital between August 2006 and March 2020 were included as controls. The MRI findings were compared between the 2 groups.

RESULTS

The mean ADC values of the mandibular condyle in patients with RA were 1.20 ± 0.17 × 10^-3 mm²/second. The mean ADC values of the mandibular condyle in patients with RA were significantly greater than the controls (P < .01). Receiver operating characteristic curve analysis revealed a cutoff of 0.89 for the ADC values of the mandibular condyle in patients with RA. The receiver operating characteristic curve analysis revealed areas under the curve for maximum ADC values of 0.98.

CONCLUSIONS

Our study found that the ADC on DWI could be used for the quantitative assessment of the mandibular condyle in patients with RA, which indicated that the ADC on DWI could be useful for predicting RA.

Findings in whole body MRI and conventional imaging in patients with fever of unknown origin-a retrospective study

Background

To analyse the influence of whole body (wb)-MRI on patient management compared to routine diagnostic tests in patients with fever of unknown origin (FUO).

Methods

Twenty-four patients with FUO, defined as illness of more than three weeks with fever greater than 38.3 °C, underwent wb-MRI at a 1.5 T MR-system. The MR-protocol consisted of the following sequences: axial T1 VIBE, coronal T2-TIRM and a coronal echoplanar diffusion weighted sequence (overall acquisition time 29:39 min:s). Furthermore, laboratory findings, chest-x-ray, abdominal ultrasound, CT-scans and/or PET-CT scans were evaluated and compared to the wb-MRI findings in regard to treatment changes.

Results

Wb-MRI yielded a correct diagnosis in 70% of the patients. In 46% the inflammatory focus was exclusively detected by wb-MRI. Focus detection by wb-MRI led to a subsequent change of the clinical management in 92% of the patients. In 6 patients both a wb-MRI and a PET-CT were performed yielding the correct diagnosis in the same 4 of 6 patients for both imaging modalities.

Conclusions

Wb-MRI appears to be of value in the evaluation of FUO patients, allowing for optimized treatment by increasing diagnostic certainty. Due to its lack of nephrotoxicity and ionizing radiation it may be preferred over standard imaging techniques and PET-CT in the future. However, given the low number of patients in our trial, further prospective studies have to be performed to confirm our results.

Clinical value of a [18F]-FDG PET-CT muscle-to-muscle SUV ratio for the diagnosis of active dermatomyositis

OBJECTIVE

To study a muscle-to-muscle standardised uptake value (SUV) ratio with FDG-PET/CT (FDG-PET) as a marker for the detection of disease activity in dermatomyositis (DM).

METHODS

Patients with DM (n = 24) who met the European Neuro-Muscular Centre diagnostic criteria were retrospectively identified over a 3-year period through a national survey. Muscle biopsy was performed in all patients. Maximum SUV was measured in proximal muscles (SUV_PROX) that had the highest radiotracer uptake on visual grading as well as in the musculus longissimus thoracis (SUV_MLT), whereas mean SUV was measured for the liver (SUV_LIV). Muscle-to-liver SUV ratios for either muscle group were compared and a SUV_PROX/SUV_MLT ratio was calculated. SUV_PROX/SUV_MLT of DM patients were compared with age- and sex-matched control subjects (n = 24) with melanoma who had received FDG-PET scans.

RESULTS

DM patients presented with proximal and symmetrical muscle uptake. Differences in SUV_PROX/SUV_LIV and SUV_MLT/SUV_LIV ratios in DM subjects were significant (p < 0.001). SUV_PROX/SUV_MLT ratios in DM and their controls also differed significantly (p = 0.0012). The SUV_PROX/SUV_MLT ratio threshold between DM subjects and controls was 1.73 with a sensitivity of 50% (CI95%, 29.1 to 70.9%) and specificity at 83.3% (CI95%, 62.6 to 95.3%). When amyopathic DM patients were removed from the analysis, specificity was increased to 95% (CI95%, 75.1 to 99.9%) with a likelihood ratio of 10 and an AUC of 83.4% (CI95%, 71.4 to 95.4%).

CONCLUSION

A muscle-to-muscle SUV_PROX/SUV_MLT ratio with a cut-off value of 1.73 in FDG-PET imaging might serve as a non-invasive marker to determine disease activity in dermatomyositis.

KEY POINTS

• [18F]-FDG PET-scanner standardised uptake value (SUV) could reflect disease activity in dermatomyositis (DM). • A ratio of SUV in proximal muscles (SUV_PROX) to SUV in musculus longissimus thoracis (SUV_MLT) could be used to determine active DM. • Active disease is suspected for SUV _PROX /SUV _MLT ratios greater than 1.73.

Characteristic Magnetic Resonance Imaging Findings in Rheumatoid Arthritis of the Temporomandibular Joint: Focus on Abnormal Bone Marrow Signal of the Mandibular Condyle, Pannus, and Lymph Node Swelling in the Parotid Glands

PURPOSE

The purpose of this study was to determine the characteristic magnetic resonance imaging (MRI) findings indicating bone and soft tissue involvement in patients with rheumatoid arthritis (RA) of the temporomandibular joints (TMJs).

PATIENTS AND METHODS

Twenty-one patients with RA and TMJ pain who underwent MRI examination of the TMJs at the authors' hospital from August 2006 to December 2014 were included in this study. Twenty-two patients with normal TMJs who underwent MRI examination at the authors' hospital from November to December 2014 were included as controls. MRI findings were compared between the 2 groups.

RESULTS

MRI findings of RA in the TMJ included 1) abnormal disc position (95.2%), 2) abnormal disc morphology (83.3%), 3) joint effusion (30.9%), 4) osseous changes in the mandibular condyle (83.3%), 5) synovial proliferation (pannus; 85.7%), 6) erosion of the articular eminence and glenoid fossa (9.52%), 7) deformity of the articular eminence and glenoid fossa (16.6%), 8) abnormal bone marrow signal in the mandibular condyle (83.3%), and 9) swelling of lymph nodes in the parotid glands (78.5%). The abnormal bone marrow signal and pannus in the mandibular condyle and lymph node swelling in the parotid glands were markedly more common in patients with RA than in controls.

CONCLUSIONS

MRI findings of RA of the TMJs were characterized by bone and soft tissue involvement, including abnormal bone marrow signal of the mandibular condyle, pannus, and swelling of lymph nodes in the parotid glands. These characteristic MRI findings could be useful in detecting RA in the TMJ in a clinical situation.

Whole-body MRI in patients with Non-bacterial Osteitis: Radiological findings and correlation with clinical data

OBJECTIVES

To correlate clinical findings of Non-bacterial Osteitis (NBO) with whole-body MRI (WB-MRI) findings and determine a radiologic index for NBO (RINBO) which allows standardized reporting of WB-MRI.

METHODS AND MATERIALS

In a prospective study, 40 patients with diagnosis of NBO underwent clinical examination and WB-MRI in which STIR- and T1- weighted images were assessed for NBO-typical lesions. Parameters of interest for RINBO were: number of radiologically active lesions (RAL), size of the patients' maximum RAL presence of extramedullary and spinal involvement. Results were tested for statistical agreement of clinical and MR-based lesion detection. RINBO was tested for correlation with clinical activity.

RESULTS

62/95 clinically/radiologically active lesions were found in 30/33 patients. In 45 % of the cohort, more active lesions were detected by WB-MRI than by clinical examination. RINBO was a significant predictor for the presence of clinically active lesions.

CONCLUSION

WB-MRI is a powerful diagnostic tool for patients with NBO which can reveal asymptomatic disease activity. With RINBO a standardized evaluation approach is proposed which helps assessing radiologic disease burden and predicts clinical disease activity.

KEY POINTS

• Whole body MRI is a powerful diagnostic tool for patients with non-bacterial Osteitis. • Whole body MRI can reveal asymptomatic disease activity. • The radiologic index RINBO offers a standardized evaluation approach.

Whole-body Magnetic Resonance Imaging in Chronic Recurrent Multifocal Osteomyelitis: Clinical Longterm Assessment May Underestimate Activity

OBJECTIVE

(1) To examine how many patients have clinically and/or radiologically active chronic recurrent multifocal osteomyelitis (CRMO) ≥ 10 years after first onset of symptoms, and (2) to compare clinical and whole-body magnetic resonance imaging (WB-MRI) findings.

METHODS

Seventeen patients (82% women) who were diagnosed with childhood-onset CRMO at least 10 years (average 12) before reexamination were reevaluated. Patients completed a standardized questionnaire, and underwent clinical and laboratory investigation and WB-MRI. Clinical features were compared with imaging findings.

RESULTS

Five patients were found to be in clinical and radiological remission. One of these patients demonstrated 1 radiologically inactive lesion on WB-MRI. Four patients showed radiologically active lesions despite full clinical remission, 2 of them in 3 vertebral bodies. Spinal involvement in 6 patients (35%) caused vertebral compression fractures, vertebra plana, or vertebral hemifusion. Eight patients presented with ongoing clinical disease activity. When applying a CRMO activity score based on clinical and imaging findings, 2 patients were identified as having pain amplification. Overall, 22/55 known CRMO lesions were identified; 11 of them were radiologically active lesions. Additionally, 14 so far unknown clinically silent lesions were detected: 8 radiologically active lesions and 6 radiologically inactive lesions.

CONCLUSION

CRMO activity on longterm followup might have been underestimated. Our study demonstrates that clinical remission does not necessarily mean radiological remission. We therefore propose that all patients with CRMO, including patients in clinical remission, require longterm clinical followup and should undergo evaluation with WB-MRI on a regular basis until radiological remission or a steady state of disease is achieved.

Role of bone scan in the assessment of polymyositis/dermatomyositis

The aim of this study was to determine the significance of bone scan findings in Korean polymyositis/dermatomyositis (PM/DM) patients. The participants in this study were 26 PM/DM patients who fulfilled the proposed criteria for definite or probable PM/DM. All patients had been examined by bone scan. The results were analyzed visually and quantitatively using the uptake ratios. Correlations between the bone scan parameters of six proximal muscle groups (trapezius, deltoid, biceps, iliopsoas, quadriceps, and gluteus medius and maximus) and clinical parameters (laboratory values and manual muscle test) representing disease activities were assessed. Based on visual analyses of their bone scans, 10 of 14 (71.4 %) patients with active PM/DM had abnormal muscle uptake. Visual grading of the bone scans had a sensitivity and specificity of 74 and 90.9 %, respectively, for the assessment of muscle inflammation. Maximal proximal muscle uptake ratios, as determined on the bone scans, were significantly higher in patients with active PM/DM than in those with inactive disease (median 1.97 vs. 1.02, p = 0.046). Maximal proximal uptake ratios correlated significantly with creatine kinase (r = 0.394, p = 0.046), lactate dehydrogenase (LDH, r = 0.473, p = 0.015), aldolase (r = 0.428, p = 0.029), erythrocyte sedimentation rate (r = 0.412, p = 0.036), C-reactive protein (r = 0.454, p = 0.002), and manual muscle test results (r = -0.399, p = 0.044). Mean proximal muscle uptake ratios correlated significantly with LDH (r = 0.438, p = 0.025) and aldolase (r = 0.572, p = 0.002). Visually assessed proximal muscle uptake grades and maximal proximal muscle uptake ratios as determined by bone scan correlated significantly with the levels of known PM/DM disease activity markers. The findings of this study suggest that bone scan is a useful imaging technique for the evaluation of PM/DM patients.

[18F]FDG uptake in proximal muscles assessed by PET/CT reflects both global and local muscular inflammation and provides useful information in the management of patients with polymyositis/dermatomyositis

OBJECTIVE

This study aimed to determine whether [(18)F]fluorodeoxyglucose-PET/CT ([(18)F]FDG-PET/CT) discriminates PM/DM from non-muscular diseases and also whether FDG uptake in proximal muscles reflects the activity and severity of muscular inflammation in PM/DM.

METHODS

Twenty treatment-naïve PM/DM patients who underwent [(18)F]FDG-PET/CT were retrospectively identified by reviewing medical records. The same number of age- and sex-matched control patients with non-muscular diseases were also identified. Standardized uptake value (SUV) was calculated for each of the seven proximal muscles. For patient-based assessment, mean proximal muscle SUV was calculated by averaging the SUVs for these proximal muscles bilaterally.

RESULTS

Mean proximal muscle SUVs were significantly greater in PM/DM patients than in control patients (median 1.05 vs 0.69, P < 0.001). Mean proximal muscle SUVs significantly correlated with mean proximal manual muscle test scores (ρ = 0.49, P = 0.028) and serum levels of creatine kinase (ρ = 0.54, P = 0.015) and aldolase (ρ = 0.64, P = 0.002). Furthermore, SUVs in proximal muscles from which biopsy specimens were obtained significantly correlated with histological grade for inflammatory cell infiltration (ρ = 0.66, P = 0.002).

CONCLUSION

Our results suggest that [(18)F]FDG-PET/CT is useful in the diagnosis of PM/DM when inflammation in proximal muscles is globally assessed with quantitative measurements. Our results also indicate that local FDG uptake in a proximal muscle reflects the activity of inflammation in the same muscle and provides useful information in determining the region for muscle biopsy.