[Magnetic resonance imaging T2 mapping could reflect disease status in patients with dermatomyositis or polymyositis].

This study aimed to explore the value of magnetic resonance imaging (MRI) T2 mapping in the assessment of dermatomyositis (DM) and polymyositis (PM). Thirty-three confirmed cases (myosin group) and eight healthy volunteers (healthy control group) at the Department of Rheumatology and Immunology, the First Affiliated Hospital of Kunming Medical University, from October 2016 to December 2017, were collected and analyzed. Multiple parameters of the myosin group were quantified, including creatine kinase (CK), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), complement C3, and complement C4. Disease status was evaluated using a panel of tools: myositis disease activity assessment tool-muscle (MDAAT-muscle), myositis disease activity assessment tool-whole (MDAAT-all), health assessment questionnaire (HAQ), medical outcomes study health survey short form-36 item (SF-36), hand muscle strength test (MMT-8) score, and MRI T2 mapping of muscle (22 muscles in the pelvis and thighs) T2 values. The results showed that in the myositis group, the measurements for CK, ESR, CRP, complement C3, and complement C4 were 457.2 (165.6, 1 229.2) IU/L, 20 (10, 42) mm/1h, 3.25 (2.38, 10.07) mg/L, 0.90 (0.83, 1.06) g/L, and 0.18 (0.14, 0.23) g/L, respectively. The scores for MMT-8, MDAAT-muscle, MDAAT-all, HAQ, and SF-36 were 57.12±16.23, 5.34 (4.00, 6.00), 34.63±12.62, 1.55 (0.66, 2.59), and 44.66±7.98, respectively. T2 values were significantly higher in all 22 muscles of the pelvis and thighs of patients with DM or PM compared with the healthy controls [(54.99±11.60)ms vs. (36.62±1.66)ms, P<0.001], with the most severe lesions in the satrorius, iliopsoas, piriformis, gluteus minimus, and gluteus medius muscles. The total muscle T2 value in the myositis group was positively correlated with CK, MDAAT-muscle, MDAAT-all, and HAQ (r=0.461, 0.506, 0.347, and 0.510, respectively, all P<0.05). There was a negative correlation between complement C4, SF-36, and MMT-8 scores (r=-0.424, -0.549, and -0.686, respectively, all P<0.05). Collectively, the findings from this study suggest that MRI T2 mapping can objectively reflect the disease status of DM and PM.

FDG PET/CT Findings of a Small Cell Carcinoma of the Lung Presented as Diffuse Dermatomyositis.

ABSTRACT: Patients with dermatomyositis are prone to have occult malignancy. A previously healthy 68-year-old man with dermatomyositis underwent FDG PET/CT to detect possible malignancy of unknown origin. The images showed not only diffuse increased activity in the muscle, which was related to the known dermatomyositis, but also intense activity in the anterior chest with foci of abnormal activity throughout the body. Pathology examination confirmed small cell carcinoma of the lung with widespread metastases.

Myofascial edema of gastrocnemius: A prominent MRI characteristic in dermatomyositis patients with anti-transcriptional intermediate factor 1-γ antibody.

AIMS: This study was designed to evaluate the magnetic resonance imaging (MRI) patterns of the lower limb muscles in dermatomyositis (DM) with anti-transcriptional intermediate factor 1-γ (anti-TIF1-γ) antibody. METHODS: This retrospective, observational, cross-sectional study enrolled 12 adult DM patients with anti-TIF1-γ antibody. Muscles were assessed for fascial edema, subcutaneous-tissue edema, muscle edema, and fatty replacement. These features were analyzed in relation to clinical characteristics. RESULTS: All 12 patients underwent hip and thigh MRI, and 8 completed calf MRI. All patients showed myofascial edema, muscle edema, and fatty replacement, and 8 out of 12 further exhibited subcutaneous-tissue edema. Specifically, myofascial edema of the gastrocnemius was observed in all patients (8/8). The vastus intermedialis and vastus lateralis muscles showed the most severe muscle edema, whereas the caput breve of the biceps femoris, semitendinosus, and soleus muscles exhibited the most severe fatty replacement. Although only 1 patient exhibited asymmetric muscle weakness, 9 showed asymmetric muscle edema, and 10 showed asymmetric fatty replacement. Changes in muscle edema positively correlated with creatine kinase (CK) levels. CONCLUSIONS: Myofascial edema of gastrocnemius was a prominent characteristic of anti-TIF1-γ-positive DM. Early detection of muscle edema, as well as CK levels, may be helpful for monitoring disease activity.

Exploring cardiovascular implications of juvenile dermatomyositis: Insights from aortic stiffness analysis and 3D echocardiography.

OBJECTIVE: Our goal was to use three dimensional (3D) strain analysis to evaluate myocardial function and ascending aorta elasticity changes in juvenile dermatomyositis (JDM). METHODS: Between 2019 and 2021, 23 JDM patients and 20 healthy volunteers participated. Both groups underwent 2D and 3D strain analysis, assessing aortic stiffness using aortic distensibility, stiffness index, strain, and elastic modulus. RESULTS: JDM patients had a median age of 13.3 ± 5.2 years, while controls had a median age of 13.8 ± 4.76 years. 3D strain analysis revealed significantly lower global longitudinal (GLS) and circumferential strain (GCS) in JDM patients compared to controls. Specifically, 3D GLS was notably reduced in patients (-28.1% vs. -31%, p = .047) compared to controls, and 3D GCS was also lower in patients (-27.5% vs. -30.5%, p = .019) compared to controls. Aortic strain and elastic modulus were significantly lower in JDM patients, while aortic stiffness index and distensibility showed no significant differences. Correlation analyses within the JDM group revealed a negative correlation between 3D GLS and age at diagnosis (r = -.561, p = .04), as well as a positive correlation between 3D GLS and both aortic strain (r = .514, p = .0001) and elastic modulus (r = .320, p = .03) in JDM patients. CONCLUSION: Our study demonstrated a trend towards lower ejection fraction and strain in patients with JDM, along with increased aortic stiffness using 3D echocardiography. These findings suggest potential cardiovascular involvement in juvenile dermatomyositis, emphasizing the importance of comprehensive cardiac assessments in these patients.

Development of a computed tomography calcium scoring technique for assessing calcinosis distribution, pattern and burden in dermatomyositis.

OBJECTIVES: To utilize whole-body CT imaging and calcium scoring techniques as tools for calcinosis assessment in a prospective cohort of patients with adult and juvenile dermatomyositis (DM and JDM, respectively). METHODS: Thirty-one patients (14 DM and 17 JDM) who fulfilled Bohan and Peter Classification criteria as probable or definite DM, the EULAR-ACR criteria for definite DM, and with calcinosis identified by physical examination or prior imaging studies were included. Non-contrast whole-body CT scans were obtained using low-dose radiation procedures. Scans were read qualitatively and quantitated. We calculated the sensitivity and specificity of calcinosis detection of physician physical exam against CT. We quantified calcinosis burden using the Agatston scoring technique. RESULTS: We identified five distinct calcinosis patterns: Clustered, Disjoint, Interfascial, Confluent and Fluid-filled. Novel locations of calcinosis were observed, including the cardiac tissue, pelvic and shoulder bursa, and the spermatic cord. Quantitative measures using Agatston scoring for calcinosis were used in regional distributions across the body. Physician physical exams had a sensitivity of 59% and a specificity of 90% compared with CT detection. A higher calcium score correlated with higher Physician Global Damage, Calcinosis Severity scores, and disease duration. CONCLUSION: Whole-body CT scans and the Agatston scoring metric define distinct calcinosis patterns and provide novel insights relating to calcinosis in DM and JDM patients. Physicians' physical examinations underrepresented the presence of calcium. Calcium scoring of CT scans correlated with clinical measures, which suggests that this method may be used to assess calcinosis and follow its progression.

Assessment of nail fold capillary changes by hand-held dermoscopy in adult dermatomyositis: A single-centre prospective study.

BACKGROUND: Hand-held dermoscopy is a valuable tool for dermatologists, but it has been rarely used to assess the nail fold capillary (NFC) in patients with dermatomyositis (DM). METHODS: Patients were collected from the Department of Dermatology and Venereology from July 2020 to July 2021, and the follow-up was conducted until January 2022. Demographic features, disease activity and NFC changes were analysed using a hand-held dermoscopy. RESULTS: The most common NFC finding in our study was bushy capillary (87.0%). There was no significant improvement in scleroderma-dermatomyositis (SD)-like nail fold changes or enlarged capillaries from baseline to 12 weeks of treatment (p > 0.05) or from 12 weeks to 24 weeks of treatment (p > 0.05), but there was a significant improvement from baseline to 24 weeks of treatment (p < 0.05). The avascular area did not improve from baseline to 12 weeks of follow-up, but the changes were significant from 12 weeks to 24 weeks of treatment (p < 0.05) and baseline to 24 weeks of treatment (p < 0.05). Periungual erythema improved significantly from baseline to 12 weeks of treatment (p < 0.05) and baseline to 24 weeks of treatment (p < 0.05), but it did not improve significantly from 12 weeks to 24 weeks of treatment (p > 0.05). There was no significant difference in disease activity between patients with or without specific NFC changes. However, some NFC features improved as disease activity decreased. CONCLUSION: Dermoscopy of NFC is a cost-effective option for the preliminary diagnosis of DM. Further, long-term follow-up is necessary to study the relationship between disease activity and NFC changes.

Intramuscular lesions in musculoskeletal MRI as a favourable prognostic sign in patients with anti-MDA5 antibody-positive dermatomyositis.

OBJECTIVES: Anti-differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis, which has been described as clinically amyopathic dermatomyositis, complicates rapidly progressive interstitial lung disease (ILD). Owing to the absence of significant muscle symptoms, musculoskeletal MRI is often not performed. In this study, we aimed to devise a simple evaluation method using musculoskeletal MRI findings to elucidate the relationship between MRI findings and ILD prognosis and development. METHODS: The medical records and MRI scans of the proximal muscles at the time of diagnosis were retrospectively reviewed for 28 patients with anti-MDA5 antibody-positive dermatomyositis who were admitted to The Jikei University Hospital and The Jikei University Kashiwa Hospital between January 2008 and March 2022. Three observers evaluated nine proximal muscles for high signals on either short-tau inversion recovery images and/or fat-saturated gadolinium-enhanced T1-weighted images in the fascia and/or in the margins of the muscles in contact with the fascia (fascial pattern), and/or high signals in the muscles away from the fascia (intramuscular pattern), and a consensus was reached. RESULTS: Of the 28 patients, 15 presented with 'radiological myositis', where an intramuscular pattern was observed at any site. Patients with radiological myositis had significantly higher survival rates than those without radiological myositis, despite the lower rate of triple therapy with prednisolone, calcineurin inhibitors and cyclophosphamide. The spread of ILD on chest CT negatively and significantly correlated with the proportion of intramuscular lesions. CONCLUSION: The detection of intramuscular lesions on musculoskeletal MRI using our novel evaluation method could be clinically useful as a favourable prognostic marker.

Improvement in Disease Activity in Refractory Juvenile Dermatomyositis Following Abatacept Therapy.

OBJECTIVE: This open-label, 24-week study was conducted to evaluate the safety and efficacy of abatacept in patients with refractory juvenile dermatomyositis (DM). METHODS: Ten patients ≥7 years of age with moderate disease activity were enrolled in a 24-week study to examine the safety of subcutaneous abatacept and patient responses to the treatment. The primary endpoint was the International Myositis Assessment and Clinical Studies (IMACS) group Definition Of Improvement (DOI). Secondary endpoints included safety, changes in the core set activity measures (CSMs) of the IMACS group and the Pediatric Rheumatology International Trials Organization, and improvements in disease activity based on the American College of Rheumatology (ACR)/EULAR response criteria for juvenile DM. Radiologists blinded with regard to participant data assessed magnetic resonance images (MRIs) of patient thigh muscles. Interferon (IFN)-regulated gene score was performed on whole-blood RNA samples using a NanoString assay, and cytokines were assessed using a Luminex assay. RESULTS: Five patients achieved DOI at week 12, and 9 patients achieved DOI at week 24, including 2 patients with minimal, 4 patients with moderate, and 3 patients with major improvement by the 2016 ACR/EULAR response criteria for juvenile DM when patients were assessed using the CSMs of the IMACS Group. Improvements from baseline were seen in all CSMs at weeks 12 and 24, except in muscle enzymes. Daily glucocorticoid doses decreased from a mean of 16.7 mg at baseline to 10.2 mg at week 24 (P = 0.002). Average MRI muscle edema scores decreased from a mean baseline score of 5.3 to 2.3 at week 24 (P = 0.01). Six patients had down-trending IFN-regulated gene scores and galectin-9 expression at week 24. Decreases in IFN-regulated gene scores and in levels of interferon-γ-inducible protein 10kDa, galectin-9, and interleukin-2 correlated with improvements in disease activity and in muscle edema shown on MRI. Eleven grade 2 or 3 treatment-emergent adverse events were observed. CONCLUSION: This open-label study demonstrated that abatacept may be beneficial for patients with treatment-refractory juvenile DM.

Features of MRI honeycomb edema signals in cancer-associated dermatomyositis patients: a brief report.

Dermatomyositis (DM) is an autoimmune inflammatory disease that is a possible paraneoplastic phenomenon. The aim of this study was to explore the difference in thigh MRI findings between DM patients with and without cancer to further assist clinicians in the early discovery of underlying malignancy. Thigh muscle MRI with T2 fs/STIR images obtained from 47 patients diagnosed with DM at a single center were retrospectively assessed for the involvement of muscle compartments, as well as the pattern and distribution of the edema signal. Among 47 patients, 14 had cancer within three years of DM diagnosis. Honeycomb edema signals were more frequently observed in cancer patients (10 in the cancer group, 11 in the noncancer group, p = 0.020), while foggy signals were not found in cancer patients. Among patients with honeycomb signals, we found that cancer patients had a relatively longer disease duration (p = 0.012), lower creatine kinase levels (p = 0.011), and barely showed adductor involvement (p = 0.016). Logistic regression analysis identified honeycomb edema signals in the quadriceps without adductor involvement as an independent risk factor for having cancer in DM patients. Honeycomb pattern edema signals showed in quadriceps but not adductors on thigh muscle MRI STIR/T2 fs sequence were more frequently found in cancer-associated DM patients. Key points • MRI honeycomb edema signals in the quadriceps without adductor involvement may be a predictor for underlying cancer in DM patients.

Thymus variants on imaging of patients with primary Sjögren's syndrome and polymyositis/dermatomyositis: clinical and immunological significance.

We investigated the presence of radiographic thymus variants using a scoring system and examined their association with clinical and immunological features in primary Sjögren's syndrome (pSS) and polymyositis/dermatomyositis (PM/DM) patients. Cases of 72 patients with pSS and 47 with PM/DM were randomly selected from all visitors to our department who received chest CT scanning, excluding those with thymoma or thymic cyst, or age <30 years. We quantitatively interpreted and assessed thymus size and attenuation score in axial CT images. Thymic enlargement was identified in 16 (22.2%) pSS and 14 (29.8%) PM/DM patients. A thymus attenuation score ≥ 2 was seen in 11 (15.3%) pSS and 9 (19.1%) PM/DM patients. Thymic enlargement showed a significant association with the titre of rheumatoid factor in PM/DM patients. Thymic enlargement and score showed a significant association with body weight in pSS patients. Radiographic thymus variants are often observed in pSS and PM/DM patients, particularly in cases of PM/DM, and may suggest the role of an abnormal immune response in their pathogenesis.

Clinical and Radiological Features of Interstitial Lung Diseases Associated with Polymyositis and Dermatomyositis.

Polymyositis and dermatomyositis are autoimmune idiopathic systemic inflammatory diseases, characterized by various degrees of muscle inflammation and typical cutaneous lesions-the latter found in dermatomyositis. The underlying pathogenesis is characterized by a high level of uncertainty, and recent studies suggest diseases may have different immunopathological mechanisms. In polymyositis, components of the cellular immune system are involved, whereas in dermatomyositis, the pathogenesis is mainly mediated by the humoral immune response. The interstitial lung disease occurs in one-third of polymyositis and dermatomyositis patients associated with worse outcomes, showing an estimated excess mortality rate of around 40%. Lung involvement may also appear, such as a complication of muscle weakness, mainly represented by aspiration pneumonia or respiratory insufficiency. The clinical picture is characterized, in most cases, by progressive dyspnea and non-productive cough. In some cases, hemoptysis and chest pain are found. Onset can be acute, sub-acute, or chronic. Pulmonary involvement could be assessed by High Resolution Computed Tomography (HRCT), which may identify early manifestations of diseases. Moreover, Computed Tomography (CT) appearances can be highly variable depending on the positivity of myositis-specific autoantibodies. The most common pathological patterns include fibrotic and cellular nonspecific interstitial pneumonia or organizing pneumonia; major findings observed on HRCT images are represented by consolidations, ground-glass opacities, and reticulations. Other findings include honeycombing, subpleural bands, and traction bronchiectasis. In patients having Anti-ARS Abs, HRCT features may develop with consolidations, ground glass opacities (GGOs), and reticular opacities in the peripheral portions; nonspecific interstitial pneumonia or nonspecific interstitial pneumonia mixed with organizing pneumonia have been reported as the most frequently encountered patterns. In patients with anti-MDA5 Abs, mixed or unclassifiable patterns are frequently observed at imaging. HRCT is a sensitive method that allows one not only to identify disease, but also to monitor the effectiveness of treatment and detect disease progression and/or complications; however, radiological findings are not specific. Therefore, aim of this pictorial essay is to describe clinical and radiological features of interstitial lung diseases associated with polymyositis and dermatomyositis, emphasizing the concept that gold standard for diagnosis and classification-should be based on a multidisciplinary approach.

Whole-body MR imaging in evaluation of children with juvenile dermatomyositis.

PURPOSE: To evaluate the whole-body MRI (WBMRI) findings in children with juvenile dermatomyositis (JDM) and correlate them with clinical and laboratory results. METHOD: We conducted the present prospective study from October 2019 to September 2021. Thirty children (8.2 ± 3.88 years) with a diagnosis of JDM based on EULAR/ACR classification criteria underwent WBMRI using short tau inversion recovery, diffusion-weighted, and T1 modified DIXON (precontrast and postcontrast) sequences. WBMRI scans were analysed independently by two radiologists for abnormal signal intensity and enhancement in the different muscle groups. Radiological findings were correlated with clinical examination, muscle enzymes, and inflammatory markers. RESULTS: WBMRI revealed abnormal signal intensity and diffusion restriction, predominantly in the thigh (n = 21, 70 % children), calf (n = 18, 60 % children), and hip (n = 16, 53.3 % children) muscles. A significant positive correlation was observed between the serum total creatinine kinase and lactic dehydrogenaselevels, with altered signal intensity and diffusion restriction in the paraspinal and thigh muscles. Diffusion restriction in the hip and calf muscles also showed significant positive correlations with these enzymes. Significant positive correlations were detected between lower limb muscle strength and altered signal intensity and diffusion restriction in the thigh (p = 0.023) and calf (p = 0.002) muscles. Postcontrast images did not yield any additional useful information. CONCLUSIONS: WBMRI provided useful information in evaluation of the extent and distribution of findings in children with JDM. There were significant positive correlations between MRI findings and muscle enzymes and clinical examination results. The addition of contrast to the WBMRI protocol did not provide any additional advantage.

Rapidly progressive interstitial lung disease in patients with anti-melanoma differentiation-associated gene 5-positive dermatomyositis: serial changes on HRCT.

BACKGROUND: Anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibodies in patients with dermatomyositis are associated with rapidly progressive interstitial lung disease (RP-ILD). Computed tomography (CT) plays a central role in the diagnosis of RP-ILD and may help characterize the temporal changes. METHODS: We report five anti-MDA5-positive dermatomyositis patients with serial CT scans spanning their acute RP-ILD disease course. RESULTS: Our case series highlights the variable imaging pattern that can manifest in this setting, including diffuse alveolar damage and nonspecific interstitial pneumonia patterns. Three patients in our series died within 4 months of their disease onset, whereas the other two patients survived. CONCLUSION: The serial CT changes in anti-MDA5 disease are dynamic and variable; therefore, it is imperative to maintain a broad differential when faced with these HRCT patterns to improve the diagnosis and management of this underrecognized entity.

Thigh MRI in antisynthetase syndrome, and comparisons with dermatomyositis and immune-mediated necrotizing myopathy.

OBJECTIVES: To evaluate MRI changes to define muscle-lesion specific patterns in patients with antisynthetase syndrome (ASS), and compare them with those in other common idiopathic inflammatory myopathy subtypes. METHODS: Qualitative and semi-quantitative thigh MRI evaluations were conducted in patients with ASS, DM and immune-mediated necrotizing myopathy (IMNM). RESULTS: This study included 51 patients with ASS, 56 with DM and 61 with IMNM. Thigh MRI revealed muscle oedema (62.7%), myofascial oedema (90.2%), subcutaneous-tissue oedema (60.8%) and fatty infiltration of muscles (68.6%) in patients with ASS. Compared with IMNM, ASS and DM were associated with more frequent adductor-muscle relative sparing (40.6% vs 3.6%, P<0.001, and 25.6% vs 3.6%, P<0.001) and subcutaneous-tissue oedema (60.8% vs 23.0%, P<0.001, and 57.1% vs 23.0%, P<0.001). Although ASS and DM exhibited similar oedema patterns, there were certain subtle differences between them. The ASS group was less frequently symmetric (60.6% vs 88.4%, P=0.005, and 60.6% vs 80.0%, P=0.048), but more frequently showed myofascial oedema of the tensor fasciae latae (80.4% vs 48.2%, P<0.001, and 80.4% vs 31.1%, P<0.001) than either the DM or IMNM groups. The receiver operating characteristic curve analysis showed an optimal combination of thigh MRI findings had an area under the curve with 0.893 for diagnosing ASS. CONCLUSION: Thigh MRI in ASS exhibited frequent myofascial oedema. ASS oedema patterns resembled those of DM more than those of IMNM. Bilateral asymmetry, adductor-muscle relative sparing and remarkable myofascial oedema of tensor fasciae latae were the most characteristic ASS imaging findings.

Preclinical ocular microvascular changes in juvenile dermatomyositis: A pilot optical coherence tomography angiography study.

OBJECTIVES: To evaluate the macular and optic nerve head (ONH) vascular density, foveal avascular zone area, and outer retina and choriocapillaris flow in juvenile dermatomyositis (JDM) using optical coherence tomography angiography (OCTA). METHODS: Ten eyes of 10 patients with JDM and 15 age and sex-matched healthy controls were investigated in this prospective, cross-sectional study. The superficial capillary plexus (SCP) and deep capillary plexus (DCP), ONH, foveal avascular zone (FAZ) parameters, the flow area of the outer retina, and choriocapillaris were evaluated using OCTA. RESULTS: Vessel density (VD) of the parafovea (p = 0.036) and parafoveal subregions (p = 0.041 for superior hemifield, p = 0.031 for inferior hemifield, p = 0.012 for superior, p = 0.019 for nasal, p = 0.026 for inferior, and p = 0.048 for temporal) in DCP were significantly lower in the JDM group compared to healthy controls. A high inverse correlation between disease duration and these parameters was found except parafoveal superior VD in DCP. There was no significant difference between the groups in VD parameters of SCP and ONH, FAZ parameters, outer retina, and choriocapillaris flow area as well as thickness parameters. (p > 0.05 for all). Furthermore, ROC analysis revealed that all parafoveal DCP parameters showed good ability to differentiate JDM from healthy controls. CONCLUSIONS: We demonstrated a decreased vessel density in the deep parafoveal region in JDM. As a result, we hypothesized that OCTA could detect retinal microvascular changes in JDM patients who did not have clinical evidence of ocular involvement.

Afectación pulmonar rápidamente progresiva secundaria a dermatomiositis juvenil anti-MDA5(+) con evolución devastadora / Interstitial lung disease in anti-MDA5 positive dermatomyositis with devastating evolution

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Adult Tiger Man: A Case of Dermatomyositis Associated With Thymoma.

ABSTRACT: The scan demonstrated multiple linear and patchy hypermetabolic lesions in skeletal muscles, mimicking the coat of a tiger, and was referred to as "a tiger man" sign. A 38-year-old man was admitted to our hospital with weakness, shortness of breath, and muscle pain. A CT scan showed a mass in the anterior mediastinum. 18F-FDG PET/CT was performed to evaluate the mass with a preliminary diagnosis of thymoma; heterogeneous 18F-FDG uptake in the mediastinal mass and tiger man findings in skeletal muscles were observed in PET/CT images.