MR Vessel Wall Imaging for Atherosclerosis and Vasculitis.

Conventional imaging modalities, such as computed tomography angiography, MR angiography, transcranial Doppler ultrasonography, and digital subtraction angiography, are utilized in evaluating intraluminal or intravascular pathology of the intracranial vessels. Limitations of luminal imaging techniques can lead to inaccurate diagnosis, evaluation, and risk stratification, as many cerebrovascular pathologies contain an extrinsic vessel wall component. Furthermore, vessel wall imaging can provide information regarding extent, treatment response, and biopsy targets for vasculitis cases. Overall, while vessel wall imaging can provide robust data regarding intracranial pathologies, further prospective, multicenter studies are required to improve diagnostic application and accuracy.

Neuroimaging Scoring Tools to Differentiate Inflammatory Central Nervous System Small-Vessel Vasculitis: A Need for Artificial Intelligence/Machine Learning?-A Scoping Review.

Neuroimaging has a key role in identifying small-vessel vasculitis from common diseases it mimics, such as multiple sclerosis. Oftentimes, a multitude of these conditions present similarly, and thus diagnosis is difficult. To date, there is no standardized method to differentiate between these diseases. This review identifies and presents existing scoring tools that could serve as a starting point for integrating artificial intelligence/machine learning (AI/ML) into the clinical decision-making process for these rare diseases. A scoping literature review of EMBASE and MEDLINE included 114 articles to evaluate what criteria exist to diagnose small-vessel vasculitis and common mimics. This paper presents the existing criteria of small-vessel vasculitis conditions and mimics them to guide the future integration of AI/ML algorithms to aid in diagnosing these conditions, which present similarly and non-specifically.

New thresholds in semi-quantitative [18F]FDG PET/CT are needed to assess large vessel vasculitis with long-axial field-of-view scanners.

AIM: [18F]FDG PET/CT proved accurate in the diagnostic work-up of large vessel vasculitis (LVV). While a visual interpretation is currently considered adequate, several attempts have been made to integrate it with a semiquantitative evaluation. In this regard, there is the need to validate current or new thresholds for the semiquantitative parameters on long-axial field of view (LAFOV) scanners. METHODS: We retrospectively evaluated 100 patients (50 with LVV and 50 controls) who underwent [18F]FDG LAFOV PET/CT. Semiquantitative parameters (SUVmax and SUVmean) were calculated for large vessels in 3 districts (supra-aortic [SA], thoracic aorta [TA], and infra-aortic [IA]). Values were also normalized to liver activity (SUVmax/L-SUVmax, and SUVmax/L-SUVmean). RESULTS: Of the 50 patients diagnosed with LVV, SA vessels were affected in 38 (76%), TA in 42 (84%) and IA vessels in 26 (52%). To-liver normalized values had higher diagnostic accuracy than non-normalized values (AUC always ≥ 0.90 vs. 0.74-0.89). For the SA vessels, best thresholds were 0.66 for SUVmax/L-SUVmax and 0.88 for SUVmax/L-SUVmean; for the TA, 1.0 for SUVmax/L-SUVmax and 1.30 for SUVmax/L-SUVmean; finally, for IA vessels, the best threshold was 0.83 for SUVmax/L-SUVmax and 1.11 for SUVmax/L-SUVmean. CONCLUSION: LAFOV [18F]FDG-PET/CT is accurate in the diagnostic workup of LVV, but different threshold in semi-quantitative parameters than reported in literature for standard scanners should be considered.

Small fetal thymus and adverse perinatal outcome in maternal vasculitis: A prospective case-control study.

BACKGROUND: Ultrasonographic evaluation of fetal thymus size may be used to predict the adverse perinatal outcome in pregnant women with vasculitis. AIM: To compare fetal thymus size in pregnant women with vasculitis and healthy pregnant women and to evaluate whether fetal thymus size predicts the adverse perinatal outcome. METHODS: Twenty-two pregnant women with previously diagnosed vasculitis, 18 of them with Behçet's disease, three with Takayasu arteritis, and one with Wegener's granulomatosis, were included in the case group. The control group comprised 66 healthy pregnant women whose gestational ages matched the case group. Thymic thoracic ratio (TTR) was measured to assess fetal thymus size in the view of three vessels and trachea. RESULTS: In the case group, fetal TTR was significantly lower (0.32 ± 0.03 vs. 0.36 ± 0.02, p = < 0.001). Fetal TTR was significantly lower in those using prednisone than those not (p = .001) in the case group. There was no significant difference in fetal TTR between colchicine used and not used (p = .078) in the case group. Also, for the TTR, a sensitivity of 100% and a specificity of 92% were achieved with a cut-off value of 0.33 for predicting adverse perinatal outcomes. CONCLUSION: The fetuses of pregnant women with maternal vasculitis had a smaller TTR. The small fetal thymus may alert clinicians to possible adverse perinatal outcomes and, with other supporting risk factors, may help predict adverse perinatal outcomes in pregnant women with vasculitis.

VEXAS Syndrome With Tracheal Involvement but Absence of Vasculitis in FDG PET/CT.

ABSTRACT: In early 2022, a 77-year-old man presented with weight loss and recurrent subfebrile temperatures since 6 months. Workup with CT revealed a lung infiltrate. Despite antibiotic treatment, serum inflammation markers remained high. The patient further developed eczematous skin changes, uveitis (sequentially on both eyes), and macrocytic anemia. Finally, an autoinflammatory disease was suspected, and FDG PET/CT was performed. The examination revealed metabolically active foci in several tissues (tracheal cartilage, bone marrow, muscles). Bone marrow aspiration revealed an UBA1 mutation, which is pathognomonic for VEXAS syndrome.

Advanced molecular imaging in large-vessel vasculitis: Adopting FDG-PET into a clinical workflow.

The use of fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging to detect vascular inflammation is increasingly common in the clinical management of patients with large-vessel vasculitis (LVV). In this review, the role of FDG-PET imaging to diagnose and monitor vascular disease activity will be detailed. Suggestions on incorporation of FDG-PET imaging into a clinical workflow will be provided with emphasis on patient preparation, image acquisition, and image interpretation. If FDG-PET imaging is obtained, multimodal imaging assessment, whereby FDG-PET imaging and non-invasive angiography are obtained concurrently, and correlation of imaging findings with clinical assessment is generally advisable. Considering the clinical scenario and treatment status of the patient is important when interpreting vascular FDG-PET image findings.

Systemic Neoplastic Cryoglobulinemic Vasculitis Mimics Large Vessel Occlusion: A Case Report.

INTRODUCTION: We describe a systemic neoplastic cryoglobulinemic vasculitis presenting as a large vessel occlusion (LVO) syndrome. We focus on a rare presentation of a rare condition. CASE REPORT: A 68-year-old man was admitted to the Stroke Unit of Padova with a right middle cerebral artery syndrome. A cerebrovascular event was suspected and protocol for revascularization treatment was performed. Neuroimaging provided no evidence for infarcted tissue or medium-large vascular occlusion but hypothesized a vasculitic involvement of the small vessels of the right hemisphere. Further diagnostics demonstrated a microangiopathic involvement of the heart, kidneys, and lungs. Blood tests showed circulating cryoglobulins and further hematological investigation identified a chronic lymphatic leukemia-like lymphoproliferative disorder. High-dose steroid therapy improved the patient's clinical status and no neurological symptoms remained at discharge. CONCLUSION: We discuss the clinical-radiologic presentation of a small vessel vasculitis that mimics an LVO stroke. This case focuses on the relevance of concomitant multiorgan manifestations in the hyper-acute evaluation of LVO stroke, suggesting the clinical neurologist should consider alternative etiologies as these could provide important clinical implications.

Cardiac Involvement in Systemic and Local Vasculitides: The Value of Noninvasive Multimodality Imaging.

Despite significant advances in managing systemic vasculitides, cardiovascular morbidity, and mortality are still of primary concern. Advances in noninvasive imaging have broadened our understanding of the clinical heterogeneity of cardiac involvement in vasculitides. Common cardiovascular complications in primary or secondary vasculitides are; coronary artery aneurysms, acute coronary syndromes, myocarditis, pericarditis, endocarditis, and valvular dysfunction. Echocardiography, cardiac magnetic resonance , positron emission tomography, and computed tomography angiography are essential in identifying cardiac involvement and guiding treatment. Here, we present our experiences of cardiac involvement in systemic vasculitides, covering most aspects of common cardiac complications based on a multi-modality approach to challenging (real-world) cases. As many cardiac manifestations are clinically silent, heart function should be systemically assessed by a multimodality imaging-based approach, including ECG, serial echocardiograms with strain imaging and 3D, and cardiac magnetic resonance to detect early signs of cardiac manifestations. This enables timely intervention and optimal medical treatment, which is essential for a better prognosis. There is a need for better and closer collaboration in clinical practice and research fields between cardiologists and rheumatologists.

Incidental findings on FDG-PET/CT in large vessel vasculitis.

This study aims to determine the number and type of incidental findings detected on positron emission tomography (PET)/CT in a cohort of patients with large vessel vasculitis (LVV). Reports from PET/CT studies along with the medical charts of a cohort of patients with LVV from a Rheumatology clinic in Edmonton, Alberta, Canada, were retrospectively reviewed. Incidental findings from PET/CT, along with follow-up studies and their diagnosis were documented. The data was analyzed with descriptive statistics. The disease activity of 40 patients, with an average age of 65.8 years, was investigated using PET/CT. A statistically significant increase in incidental findings with age was observed. A total of 61 incidental findings were found in 26 (65%) patients. Of these findings, 25 were in the abdomen and pelvis. The most common incidental finding was lymphadenopathy. Follow-up investigations of incidental findings lead to 5 clinically significant findings including metastatic adenocarcinoma, Mycobacterium avium infection, papillary thyroid carcinoma, pheochromocytoma, and stroke. PET/CT is a reliable tool for determining disease activity in LVV patients and the implications of incidental findings need to be discussed with patients by the ordering care provider. This study demonstrates that incidental findings on PET/CT scan are common and increase with age in patients with LVV. A significant number of patients required further investigation for incidental findings. Key Points • Incidental findings on PET/CT scan are common in our patient population with LVV. • Frequency of incidental findings in our patient population with LVV increased with age. • Findings from this study can be used by ordering providers to have an informed conversation with their patient about the frequency of incidental findings on PET/CT scans.

Positron Emission Tomography Imaging in Vasculitis.

Systemic vasculitides comprise a group of autoimmune diseases affecting blood vessels. [18F]-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT) plays an important role in the diagnosis and therapeutic monitoring of vasculitides affecting large-sized and medium-sized vessels. FDG-PET/CT also provides complementary information to other vascular imaging tools. The resolution and sensitivity of newer generation scanners continues to increase, hereby improving the ability of FDG-PET/CT to accurately assess the full disease extent in patients with vasculitis. Novel tracers targeting specific immune cells will allow for more detailed detection of vascular infiltrates.

Differentiation of lower limb vasculitis from physiological uptake on FDG PET/CT imaging.

PURPOSES: To analyze the difference of 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) uptake between vasculitis and non-vasculitic patients in PET/CT imaging and the factors related to vascular uptake in non-vasculitic patients. To investigate the feasibility of identifying vasculitis of the lower limb and physiological uptake with delayed imaging. PROCEDURES: Among 244 patients who underwent PET/CT examination, imaging features of patients with or without vasculitis were retrospectively analyzed. The factors related to FDG uptake in the lower limb vessels of non-vasculitic patients were analyzed. Another 44 patients with suspected systemic vasculitis in PET/CT were prospectively studied to analyze the efficacy of delayed imaging on differentiating vascular uptake in lower limbs. RESULTS: In PET/CT imaging of patients with vasculitis, involvement of trunk vessels showed segmental or diffuse FDG distribution. Lower limb vascular involvement showed reticular uptake accompanied by nodular or patchy changes. In non-vasculitic patients, vascular uptake mainly showed linear uptake in lower limb vessels and there was no significant difference in uptake degree compared with vasculitis patients. Body weight and interval time were the independent influence factors of vascular uptake in lower limbs of non-vasculitic patients. In delayed imaging, lower limb vasculitis all showed reticular uptake and physiological uptake all showed a linear pattern. ROC analysis showed the change rate of SUVmax (≥ 20%) between early and delayed imaging could delineate physiological vascular uptake with a sensitivity of 100% and specificity of 81.0%. CONCLUSIONS: When PET/CT is used for the diagnosis and classification of vasculitis, the physiological uptake of lower limb vessels may mislead the diagnosis. PET/CT imaging features or delayed imaging improved diagnostic efficacy.

Acute pancreatitis associated with immunoglobulin A vasculitis: report of fifteen cases.

OBJECTIVE: Immunoglobulin A vasculitis (IgAV) is a systemic small vessel vasculitis common in children. Pancreatic involvement in IgAV is rare. The purpose of this study was to analyze the clinical characteristics of IgAV-related acute pancreatitis in children. METHODS: Records of patients with IgAV-related acute pancreatitis admitted to our institution between January 2016 and December 2019 were reviewed. We summarized the clinical characteristics, laboratory characteristics, imaging findings, treatment, and outcomes of 15 children with IgAV-related acute pancreatitis. RESULTS: The patients' median age was 9.6 years. Pancreatitis was the initial manifestation of IgAV in 3 patients. All patients had abdominal manifestations, including abdominal pain (15/15), vomiting (10/15), and gastrointestinal bleeding (7/15). Serum amylase and lipase levels were elevated in all patients. Serum amylase in 4 cases reached more than three-fold elevation and serum lipase in 14 cases reached more than three-fold elevation. Morphological abnormalities and abnormal signals of the pancreas were observed in 13 cases by magnetic resonance imaging. Pancreaticobiliary maljunction was seen in 3 cases by magnetic resonance cholangiopancreatography. Glucocorticoid therapy and intravenous immunoglobulins were used to treat acute pancreatitis in IgAV. All patients showed clinical improvement after treatment. During the follow-up period of 6-12 months, all 15 cases with pancreatitis were cured without recurrence. CONCLUSIONS: Pancreatic involvement is rare in IgAV; however, this should be considered in IgAV patients with severe abdominal pain. The timely application of steroid therapy is important for IgAV-associated pancreatitis. Key Points • Acute pancreatitis is a rare complication of immunoglobulin A vasculitis (IgAV). • Acute pancreatitis can be the initial manifestation of IgAV. It is important to evaluate for pancreatitis while IgAV patients with severe abdominal pain. • A common image finding of IgAV-associated pancreatitis was swelling of the pancreas. • Glucocorticoid therapy and intravenous immunoglobulins is helpful in alleviating acute pancreatitis in IgAV.

Neurogenic intermittent claudication caused by vasculitis in the cauda equina: an autopsy case report.

PURPOSE: Intermittent claudication (IC) refers to leg pain that is induced by walking and relieved by rest. Neurogenic IC is usually associated with lumbar canal stenosis (LCS). We present rare findings from an autopsied patient who had neurogenic IC caused by vasculitis in the cauda equina. METHODS: We performed antemortem neurological and electrophysiological assessments, sural nerve biopsy, and post-mortem examination of the spinal cord and brain. RESULTS: A 61-year-old man noted sudden-onset leg pain that was not associated with any traumatic trigger. His leg pain consistently appeared when the patient walked and quickly faded on stopping. Spine surgery and cardiovascular departments both made a diagnosis of IC. However, magnetic resonance imaging (MRI) did not show LCS, and all ankle-brachial pressure indices were normal. He subsequently developed diffuse muscle weakness of the legs a month after disease onset. Myeloperoxidase antineutrophil cytoplasmic autoantibody was seropositive (140 IU/mL), and a sural nerve biopsy revealed axonal injury and angiitis. MRI showed multiple cerebral infarctions. He was diagnosed with microscopic polyangiitis (MPA) and underwent corticosteroid therapy. He died from complications two months after the onset. A post-mortem study revealed vasculitis in the subarachnoid space of the cauda equina, spinal cord, and brain parenchyma. The cauda equina showed a combined loss of small and large axonal fibres. The lumbar cord displayed central chromatolysis of the lower motor neurons. CONCLUSION: MPA is a rare cause of neurogenic IC when the symptom is acute and multimodal. Small-vessel vasculitis affecting the cauda equina may underlie MPA-associated IC.

Vessel inflammation and morphological changes in patients with large vessel vasculitis: a retrospective study.

OBJECTIVE: The aim was to identify any association between imaging signs of vessel wall inflammation (positron emission tomography-CT (PET-CT) score and CT/MR wall thickening) and synchronous and subsequent vascular damage (stenoses/dilations) in patients with large vessel vasculitis (LVV). METHODS: Consecutive patients with LVV referred to a tertiary centre in 2007-2020 with baseline PET-CT and morphological imaging (CT/MR angiography) performed within 3 months were included. All available PET-CT and CT/MR scans were reviewed to assess PET-CT uptake (4-point semi-quantitative score), wall thickening, stenoses and dilations for 15 vascular segments. The associations of baseline PET score and CT/MR wall thickening with synchronous and incident stenoses/dilations at CT/MR performed 6-30 months from baseline were evaluated in per-segment and per-patient analyses. Respective areas under the receiver operating characteristic curve (AUC) were calculated. RESULTS: We included 100 patients with LVV (median age: 48 years, 22% males). Baseline PET score and wall thickening were strongly associated (Cuzick non-parametric test for trend across order groups (NPtrend) <0.001). The association with synchronous stenoses/dilations was weak for PET score (NPtrend=0.01) and strong for wall thickening (p<0.001). In per-patient analyses, sensitivity/specificity for ≥1 synchronous stenoses/dilations were 44%/67% for PET score ≥2 and 66.7%/60.5% for wall thickening. Subsequent CTs/MRs were available in 28 patients, with seven incident stenoses/dilations. Baseline PET score was strongly associated with incident stenoses/dilations (p=0.001), while baseline wall thickening was not (p=0.708), with AUCs for incident stenoses/dilations of 0.80 for PET score and 0.52 for wall thickening. CONCLUSION: PET score and wall thickening are strongly associated, but only baseline PET score is a good predictor of incident vessel wall damage in LVV.

Interstitial disease associated with connective tissue disease and vasculitis.

Systemic autoimmune diseases comprise a complex, heterogeneous group of entities. Noteworthy among the pulmonary complications of these entities is interstitial involvement, which manifests with the same radiopathologic patterns as in idiopathic interstitial pneumonia. High-resolution computed tomography is the gold-standard imaging technique; it enables us to identify and classify the disease and to determine its extent, providing useful information about the prognosis. In this group of processes, the most common pattern of presentation is nonspecific interstitial pneumonia. It is essential for radiologists to work together in collaboration with other specialists to reach the correct diagnosis and enable appropriate, integrated treatment.