Exploring the Labyrinth: Imaging in Systemic Vasculitis.

Systemic vasculitis is an immune-mediated group of disorders broadly classified based on the involved vessel type. It has myriad clinical presentations, adding to the challenge of timely diagnosis and management. Thus, imaging has taken center stage in the diagnosis of these disorders as there is a lack of definitive clinical diagnostic markers. Various available imaging modalities can be used for diagnosis and follow-up on these patients. The coronavirus disease 2019 (COVID-19) has added a new dimension to the already existing problem of vasculitis. The virus has shown great affinity for the vascular endothelium, leading to multisystem organ vasculitis. There has been a spike in vasculitis cases in the COVID-19 pandemic era, thus necessitating more research and studies in this field for a better understanding of the disease. In this review, we wish to summarize the various imaging spectrums of classical systemic vasculitis along with the new addition of COVID-19-related vasculitis to the already long list.

Imaging features of 18F-FDG PET/CT in different types of systemic vasculitis.

OBJECTIVE: To analyze 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) image features in different types of systemic vasculitis and explore its classification and diagnostic significance for systemic vasculitis. METHODS: Clinical and 18F-FDG PET/CT imaging data of 71 consecutive patients (34 males, 37 females, mean age 53.4 ± 20.5 years) who were examined at Peking University People's Hospital and diagnosed with active systemic vasculitis were analyzed retrospectively, and 18F-FDG PET/CT imaging features of different types of systemic vasculitis were analyzed in patients with positive 18F-FDG PET/CT findings. RESULTS: The proportions of large-, medium-, small-, and variable-vessel vasculitis were 36.6%, 15.5%, 29.6%, and 18.3%, respectively, and 93.0% of patients had positive findings on PET/CT, of which 63.6% had vascular involvement and 53.0% had extravascular involvement. Different types of vasculitis had different lesion sites, distribution patterns, and morphological changes. Large-vessel vasculitis mainly affected the aorta and its branches to the head and neck. Takayasu arteritis showed segmental involvement of the vascular and morphological changes of the vessel wall. Giant cell arteritis manifested as diffuse vascular involvement, which usually involved the temporal artery and the abdominal aorta and its branches. Medium-vessel vasculitis polyarteritis nodosa manifested as diffuse vascular involvement of both lower extremities. Small-vessel vasculitis anti-neutrophil cytoplasmic antibody-associated vasculitis manifested as granulomatous inflammation of extravascular regions. Variable-vessel vasculitis Behcet's disease involved both blood vessels and extravascular regions. CONCLUSION: Different types of systemic vasculitis show characteristic manifestations in 18F-FDG PET/CT images, which may be useful for the diagnosis and classification of systemic vasculitis. KEY POINTS: • Determining an early diagnosis of systemic vasculitis may be challenging. • Different types of systemic vasculitis show characteristic manifestations in 18F-FDG PET/CT images. • 18F-FDG PET/CT may be useful for the diagnosis and classification of systemic vasculitis.

Systemic vasculitides and the role of multitechnique imaging in the diagnosis.

Vasculitis, a systemic disease characterised by inflammation of the blood vessels, remains challenging to diagnose and manage. Vessel size has been the basis for classifying systemic vasculitides. Imaging plays a vital role in diagnosing this challenging disease. This review article aims (a) to summarise up-to-date literature in this field, as well as include classification updates and (b) to review available imaging techniques, recent advances, and emphasis on imaging findings to diagnose large vessel vasculitides.

An atypical lower limb pain revealing a possible systemic venous vasculitis.

We describe a possible systemic vasculitis involving electively large veins. The patient presented with severe febrile lower limb pain. Diagnosis was made by color Doppler ultrasound (CDU) and confirmed by anatomopathological examination of the long saphenous vein, but not by examination of the temporal artery which was normal. CDU found a unilateral halo sign of one temporal artery and a major wall swelling of the lower limb proximal deep veins. The etiology of this possible vasculitis is still unknown. It could be an unusual clinical presentation of giant cell arteritis with vein involvement but without proven arterial involvement. To confirm this hypothesis, it would be interesting to look systematically for lower limb vein thickening with CDU in patients newly diagnosed with giant cell arteritis who have lower limb pain.

Femoral vein wall thickness measurement: A new diagnostic tool for Behçet's disease.

OBJECTIVES: Diagnosing Behçet's disease (BD) is a challenge, especially in countries with a low prevalence. Recently, venous wall thickness (VWT) in lower extremities has been shown to be increased in BD patients. In this study, we aimed to investigate the diagnostic performance of common femoral vein (CFV) thickness measurement in BD and whether it can be used as a diagnostic tool. METHODS: . Patients with BD (n = 152), ankylosing spondylitis (n = 27), systemic vasculitides (n = 23), venous insufficiency (n = 29), antiphospholipid syndrome (APS; n = 43), deep vein thrombosis due to non-inflammatory causes (n = 25) and healthy controls (n = 51) were included in the study. Bilateral CFV thickness was measured with ultrasonography by a radiologist blinded to cases. RESULTS: Bilateral CFV thickness was significantly increased in BD compared with all control groups (P < 0.001 for all). The area under the receiver operating characteristic curve for bilateral CFV thicknesses in all comparator groups was >0.95 for the cut-off value (0.5 mm). This cut-off value also performed well against all control groups with sensitivity rates >90%. The specificity rate was also >80% in all comparator groups except APS (positive predictive value: 79.2-76.5%, negative predictive value: 92-91.8% for right and left CFV, respectively). CONCLUSION: Increased CFV thickness is a distinctive feature of BD and is rarely present in healthy and diseased controls, except APS. Our results suggest that CFV thickness measurement with ultrasonography, a non-invasive radiological modality, can be a diagnostic tool for BD with sensitivity and the specificity rates higher than 80% for the cut-off value ≥0.5 mm.

Early large vessel systemic vasculitis in adults.

Giant cell arteritis (GCA) is the most common vasculitis in individuals older than 50 years in Western countries. In addition to the typical pattern of cranial ischemic manifestations, large vessel vasculitis (LVV) involvement has emerged as a common feature of GCA. Patients with predominant LVV manifestations differ from those with the cranial pattern. They are usually affected at a younger age and often have nonspecific manifestations such as constitutional syndrome, fever of unknown origin, or refractory/atypical polymyalgia rheumatica (PMR). In these patients, cranial manifestations are often absent. Furthermore, patients with isolated PMR should be followed up because of the potential risk of severe vascular complications in the setting of an underlying GCA. Whereas temporal artery biopsy and/or color duplex ultrasound of the temporal arteries is useful for the diagnosis of cranial GCA, Doppler sonography of the subclavian and axillary arteries, fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography, magnetic resonance, and computed tomography-angiography are very useful to identify the presence of LVV, and they may play a potential role in the follow-up of these patients.

Clinical Applicability of Ultrasound in Systemic Large Vessel Vasculitides.

The systemic large vessel vasculitides consist mainly of giant cell arteritis and Takayasu arteritis. Both diseases affect the large blood vessels and can lead to ischemia and end-organ damage. Ultrasound is an imaging technique that can depict inflammation of the vessel wall in large and medium vessel vasculitis. In this article, we critically review the current evidence for the clinical use of ultrasound for systemic large vessel vasculitides, regarding the clinical applicability, technical requirements, challenges, and cost. A roadmap for the development of a fast-track ultrasound clinic for giant cell arteritis is also provided.

Advances in Therapies and Imaging for Systemic Vasculitis.

Vasculitis is a systemic disease characterized by immune-mediated injury of blood vessels. Current treatments for vasculitis, such as glucocorticoids and alkylating agents, are associated with significant side effects. Furthermore, the management of both small and large vessel vasculitis is challenging because of a lack of robust markers of disease activity. Recent research has advanced our understanding of the pathogenesis of both small and large vessel vasculitis, and this has led to the development of novel biologic therapies capable of targeting key cytokine and cellular effectors of the inflammatory cascade. In parallel, a diverse range of imaging modalities with the potential to monitor vessel inflammation are emerging. Continued expansion of combined structural and molecular imaging using positron emission tomography with computed tomography or magnetic resonance imaging may soon provide reliable longitudinal tracking of vascular inflammation. In addition, the emergence of radiotracers able to assess macrophage activation and immune checkpoint activity represents an exciting new frontier in imaging vascular inflammation. In the near future, these advances will allow more precise imaging of disease activity enabling clinicians to offer more targeted and individualized patient management.

Imaging the Vasculitides.

"Neuroimaging plays a vital role in the diagnosis of primary and secondary vasculitic disorders. There multiple neuroimaging options available to accurately describe the underlying clinical deficits of involved cases. Noninvasive neuroimaging modalities provide less risk and when interdigitated, form the basis for a more conclusive understanding of the disease process. There are instances in which invasive cerebral angiography may be needed to image the intricate and at times, small involved vessels. Neuroradiologists should be included in the multidisciplinary team of physicians caring for patients with vasculitides and in research to provide more sensitive and safe modalities for accurate diagnosis."

Position article and guidelines 2018 recommendations of the Brazilian Society of Rheumatology for the indication, interpretation and performance of nailfold capillaroscopy.

Nailfold capillaroscopy (NFC) is a reproducible, simple, low-cost, and safe imaging technique used for morphological analysis of nail bed capillaries. It is considered to be extremely useful for the investigation of Raynaud's phenomenon and for the early diagnosis of systemic sclerosis (SSc). The capillaroscopic pattern typically associated with SSc, scleroderma ("SD") pattern, is characterized by dilated capillaries, microhemorrhages, avascular areas and/or capillary loss, and distortion of the capillary architecture. The aim of these recommendations is to provide orientation regarding the relevance of NFC, and to establish a consensus on the indications, nomenclature, the interpretation of NFC findings and the technical equipments that should be used. These recommendations were formulated based on a systematic literature review of studies included in the database MEDLINE (PubMed) without any time restriction.

Investigations in systemic vasculitis - The role of imaging.

Imaging plays an increasing role for confirming a suspected diagnosis of giant cell arteritis (GCA) or Takayasu arteritis (TAK). Ultrasound, magnetic resonance imaging (MRI), and computed tomography demonstrate a homogeneous, most commonly concentric, arterial wall thickening. 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) displays increased FDG uptake of inflamed artery walls delineating increased metabolism. Ultrasound and MRI are recommended to be the initial imaging modalities in cranial GCA and TAK, respectively. Extracranial disease can be confirmed by all four modalities, particularly by PET in case of inflammation of unknown origin. If the diagnosis remains uncertain, additional investigations including biopsy and/or additional imaging are recommended. Imaging should be performed by a trained specialist using appropriate operational procedures and settings with appropriate equipment. Further research is necessary on the role of imaging for disease monitoring. This review will discuss advantages and disadvantages of imaging modalities in the diagnosis of vasculitis.

Combined brain and heart magnetic resonance imaging in systemic vasculitides: fiction or real need?

Systemic vasculitides (SVs) is a group of diseases characterised by inflammation/necrosis of the blood vessel wall in various organs. Simultaneous brain and heart involvement is a cause of increased morbidity/mortality in SV. We aimed to present evidence of concurrent brain/heart involvement in SV and the role of a combined brain/heart magnetic resonance imaging (MRI) in their risk stratification. Cerebral vasculitis (CV) can be presented as focal deficits, seizures, headache, neuropsychiatric manifestations or cognitive dysfunction and cardiovascular disease (CVD) as myocardial/vascular inflammation, perfusion/function defects and fibrosis. MRI is a non-invasive, non-radiating technique that allows the reliable identification of intraparenchymal brain lesions and the detection of myocardial/vascular inflammation and fibrosis. However, its use in SV is currently hampered by high cost, lack of availability/expertise and lack of awareness among the clinicians. Although there are no clinical data supporting the combined use of brain/heart MRI in asymptomatic SV, it would be called for in cases with clinical suspicion of brain/heart involvement, especially in those at high risk for CVD/stroke such as SLE/APS. Furthermore, it may be of value in SV with multi-organ involvement, cognitive dysfunction or other neuropsychiatric symptoms with concurrent cardiac involvement, presenting as typical or atypical symptoms with normal routine cardiac evaluation, new onset of arrhythmia and/or HF.

Acute gastric dilatation in a patient with lupus nephritis: An uncommon presentation of lupus mesenteric vasculitis.

Abdominal symptoms are common in patients with lupus nephritis and are often attributed to drugs or uremia per se. Lupus mesenteric vasculitis (LMV) or lupus enteritis is a rare entity reported in patients with active systemic lupus erythematosus. It usually occurs in patients with a long-standing history of lupus with high disease activity. Usually, small bowel is predominantly affected. The stomach and rectum are spared in view of significant collateral circulation. Here, we describe an 18-year-old boy who presented with nephrotic syndrome without any extrarenal features of lupus. On subsequent evaluation, he was found to have active lupus nephritis. He developed acute gastric dilatation secondary to extensive LMV. Imaging showed an extensive involvement of gastrointestinal tract from the stomach to the sigmoid colon, sparing the rectum. To the best of our knowledge, this is the first report of LMV presenting as acute gastric dilatation.

CHARACTERISTICS OF ARTICULAR SYNDROME IN SYSTEMIC VASCULITIS.

The purpose of the study - investigation the separate joint lesion in systemic vasculitis, their X-ray sonographic characteristics, the correlation of the articular syndrome severity with extra-articular manifestations of the diseases, as well as aspects of the arthritis pathogenesis in this category of patients. The study included 525 patients in the ratio of the examined with Henoch-Schonlen purpura, microscopic polyangiitis, cryoglobulinemic vasculitis, polyarteritis nodosa, Takayasu's arteritis, Wegener's granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis Churg-Strauss as a 7:4:3:1:1:1:1. Joint's damage in the form of arthritis or arthralgia observed in 32-67% different groups of patients, that depending on the disease duration, the degree of the pathological process's activity, extraarticular signs severity, lung parenchyma involving and hemodynamic status in the pulmonary circulation. The frequency of the certain bone lesions, existence of tenosynovitis and enthesopathies, X-ray sonographic signs of articular syndrome in different kind of vasculitis has its own gender dimorphism. The immune system malfunction, the rheological properties of blood and endothelial function of vessels collaborate in pathogenetic constructions of arthropathy. What is more, the high value of rheumatoid factor in blood associates with severe course of joint damage. Joint syndrome at different variants of systemic vasculitis is progressing in 1/3-2/3 of cases, this syndrome has definite features of clinical course and pathogenesis.

Occlusive vasculopathy in human immunodeficiency virus (HIV)-associated vasculitis: unusual clinical and imaging course.

Human immunodeficiency virus (HIV)-associated vasculitis is a rare secondary systemic vasculitis involving small and medium arteries. We report a 42-year-old man with uncontrolled HIV infection presenting with long-lasting abdominal pain. An abdominal CT angiography revealed multiple microaneurysms and stenoses in intrarenal arteries, with involvement of mesenteric and hepatic arteries. HIV-associated vasculitis was diagnosed and glucocorticoids and raltegravir-based antiretroviral therapy were administered with good initial clinical and virological response. Several episodes of acute intestinal ischaemia were later developed requiring bowel resections of which histological examination showed vascular occlusive fibrotic changes without active vasculitic lesions. Vasculitis persisted in remission and intrarenal microaneurysms disappeared.

The Expanding Role of Imaging in Systemic Vasculitis.

Various imaging modalities, including color duplex ultrasonography, CT angiography, magnetic resonance angiography, and PET, are emerging as important aids to the diagnosis, staging, evaluation of disease activity and response to treatment in systemic vasculitis. Although large-vessel vasculitis is the main target of imaging, refinement and increasing accuracy of imaging modalities are also providing useful information in the evaluation of medium-vessel and small-vessel vasculitis.

Acute ST elevation myocardial infarction in fulminant systemic p-ANCA vasculitis: a rare catastrophic complication.

A 45-year-old Caucasian man presented to the hospital with a 3-month history of fatigue, bilateral upper and lower limb paresthesias and gradually worsening ascending paralysis. A few weeks later, he developed acute renal failure requiring haemodialysis. Investigations revealed presence of myeloperoxidase (MPO) perinuclear antineutrophil cytoplasmic antibodies (ANCA). Renal biopsy was conclusive for rapidly progressive glomerulonephritis with crescents. Treatment for ANCA positive vasculitis was initiated with pulsed steroids, cyclophosphamide and plasmapheresis. The hospital course took an unexpected turn when the patient developed acute chest pain with an EKG consistent with inferior ST elevation myocardial infarction (STEMI). Urgent left heart catheterisation revealed distal occlusions in multivessel coronary distribution. Coronary involvement is rare in ANCA vasculitis and STEMI has not been reported in MPO-ANCA positive vasculitis, to the best of our knowledge.

Monitoring Vasculitis with 18F-FDG PET.

Whereas in the past the term "vasculitis" was most frequently used in context with systemic vasculitides, such as the large vessel vasculitides (LVV) Takayasa arteritis and giant cell arteritis, characterized by inflammation of blood vessel walls, it nowadays comprises also inflammatory changes of the vessel wall as a substantial part of the atherosclerotic disease process. Implementing non-invasive imaging techniques, such as computed tomography angiography (CTA), magnetic resonance angiography (MRA) as well as positron emission tomography (PET) in the diagnostic algorithm of atherosclerosis and LVV, depicts a promising step towards an earlier detection with a, consecutively, improved therapeutic approach and potentially prognostic benefit in patients suffering from vasculitis. Mainly molecular imaging with 18F-fluorodeoxyglucose (FDG) PET seems to be promising in offering an early and sensitive identification of inflammatory changes in both, atherosclerosis and LVV. This review will therefore provide an overview on the diagnostic performance and clinical relevance of FDG-PET in monitoring vasculitis in atherosclerosis and LVV, with a focus on LVV.