Diagnosis Of Giant Cell Arteritis Research Articles

Performance of a fast-track pathway for giant cell arteritis in Waikato, Aotearoa New Zealand.

Giant cell arteritis (GCA) is the most common primary vasculitis in adults over 50 years of age. To facilitate early diagnosis and reduce harms from corticosteroids and temporal artery biopsies, fast-track pathways have been established. We review the benefits of the fast-track pathway set up in Waikato, Aotearoa New Zealand. Patients were collected prospectively as part of the fast-track pathway from 2014 to 2022. Their records were then reviewed retrospectively to collect data on clinical features, investigations and treatment. There were 648 individual patients over the study period who had a colour Doppler ultrasound (CDUS) of the temporal arteries. There were 17 true positive CDUS, giving a sensitivity of 10.3% (95% confidence interval [CI] 6.3-15.5%) and specificity of 99.8% (95% CI 99.1-100%). Patients with GCA and a positive scan had significantly fewer steroids than those with GCA and a negative scan (p=0.0037). There were 376 patients discharged after a CDUS who did not have a diagnosis of GCA, resulting in reduced corticosteroid and temporal artery biopsy exposure. This is a real-life study that reflects the benefits of fast-track pathways in Aotearoa New Zealand to patients and healthcare systems. It also shows the effect of corticosteroids on positive CDUS, an important consideration when setting up an fast-track pathway.

Sudden Visual Loss due to Arteritic Anterior Ischaemic Optic Neuropathy: A Rare Manifestation of Eosinophilic Granulomatosis with Polyangiitis.

eosinophilic granulomatosis with polyangiitis (EGPA) is a rare multisystem inflammatory disease characterized by asthma, eosinophilia and granulomatous or vasculitic involvement of various organs. While the eye is uncommonly affected in patients with EGPA, multiple ophthalmic manifestations have been reported, which can result in serious visual impairment without timely treatment. we report the case of a 79-year-old woman with a history of asthma and nasal polyps who presented with low-grade fever, mild alteration of mental status, and fatigue. Chest X-ray revealed bilateral interstitial infiltrates. Lab tests showed elevated C-reactive protein level and eosinophilia (eosinophil count, 4.6 x109 cells/l); blood cultures and parasitological examination of stools tested negative. Four days after presentation, the patient reported sudden and severe blurring of vision in her left eye. Ophthalmological examination revealed bilateral swollen optic disc and visual field loss, more severe in the left eye. A diagnosis of EGPA complicated by arteritic anterior ischaemic optic neuropathy (A-AION) was proposed, while an alternative or concurrent diagnosis of giant cell arteritis was ruled out based on clinical picture. Immunosuppressive treatment with high-dose intravenous glucocorticoids was promptly started. The patient's visual defect did not improve; however, two months later, no worsening was registered on ophthalmic reassessment. A-AION is an infrequent but severe manifestation of EGPA, requiring prompt diagnosis and emergency-level glucocorticoid therapy to prevent any further vision loss. Disease awareness and a multidisciplinary approach are crucial to expedite diagnostic work-up and effective management of EGPA-related ocular complications. Arteritic ischaemic optical neuropathy is a potential cause of sudden and severe visual loss in eosinophilic granulomatosis with polyangiitis (EGPA) patients.Visual loss due to arteritic ischaemic optical neuropathy is rarely reversible; however, a timely glucocorticoid treatment may prevent further progression of visual impairment.Multidisciplinary approach is crucial to expedite diagnostic work-up and effective management of EGPA patients with ocular complications.

Visualization of the Internal Thoracic Arteries in Giant Cell Arteritis on 18 F-FDG Semiconductor PET/CT.

A 72-year-old woman presented with the fever and the pain of skull and face for 2 weeks. 18 F-FDG PET/CT equipped with semiconductor detectors revealed strong uptake not only in the temporal, cervical, subclavian arteries, and aorta, but also in the bilateral internal thoracic arteries. The diagnosis of giant cell arteritis was made. Semiconductor PET can visualize small arteries such as the internal thoracic artery. The patients with giant cell arteritis are at a high risk of ischemic heart disease, and inflammatory involvement of the internal thoracic arteries may affect the outcome of coronary artery bypass grafting.

Upper respiratory tract and orofacial manifestations of new-onset giant cell arteritis: results from a large, prospective inception cohort study.

Giant cell arteritis (GCA) often features upper respiratory tract (URT) and orofacial manifestations, which signal the involvement of external carotid artery branches. In this study, we aimed to describe the frequency of various URT/orofacial symptoms at GCA onset, as well as the main characteristics of patients presenting these symptoms. We included all patients who were newly diagnosed with GCA between 1976 and April 2022 at the Internal Medicine Department of a tertiary-care hospital. Ten URT or orofacial symptoms were prospectively examined systematically in each patient. We used multivariate analyses to identify the GCA characteristics, including URT/orofacial symptoms, associated with temporal artery biopsy (TAB) positivity. At least 1 URT/orofacial symptom was present in 68.6% of the 599 patients (3 or more symptoms in 30% of cases). Jaw claudication, maxillary pain, and pain during mouth opening were the most prevalent symptoms. Dry cough was recorded in 17% of cases. GCA patients with URT/orofacial symptoms had more clinical abnormalities of the temporal artery bed and ischaemic ophthalmological complications, but less large-vessel vasculitis according to imaging. The likelihood of a positive TAB was increased in patients with an abnormal temporal artery upon clinical examination (OR 4.16; CI 2.75-6.37, p < 0.001) or jaw claudication (OR 2.18; CI 1.35-3.65, p = 0.002), and decreased in those with hoarseness (OR 0.47; CI 0.26-0.87, p = 0.02) or earache (OR 0.54; CI 0.31-0.95, p = 0.03). Isolated URT/orofacial presentation (i.e., without headache or visual signs) accounted for 5.2% of the entire cohort. Oral-facial symptoms were present in two-thirds of GCS cases. Thus, they could serve as leading clinical clues for a GCA diagnosis, and are a risk factor for permanent visual loss. Several URT/orofacial symptoms such as jaw claudication, hoarseness, and earache influenced the likelihood of a positive TAB. Isolated URT/orofacial presentation of GCA is a rare but potentially challenging occurrence.

Diagnosis of giant cell arteritis by 18F-FDG PET/CT in patients on glucocorticoid therapy: importance of delayed imaging.

The aim of this study is to analyse the diagnostic value of positron emission tomography (PET) in patients with giant cell arteritis (GCA) despite glucocorticoid (GC) therapy before PET acquisition. Consecutive patients with strongly suspected GCA according to 2022 EULAR/ACR criteria were included. The physician diagnosis of GCA after 6 months of follow-up was the gold standard. PET was performed at baseline and 6 months later. In patients with negative results at 60 min, delayed imaging was performed at 180 min. Twenty-six patients were included with a median (IQR) age of 70.5 (57-88) years. Baseline PET was positive in all but one: 18 patients at 60 min and 7 patients after delayed imaging at 180 min. The median (IQR) GC dose at the time of baseline PET was 45 mg/d (26.2-45) of prednisone equivalent with a median exposure of 14 days (7-76.2). At 6 months of follow-up, PET was performed in 22 patients, with positive results in 16. Delayed imaging was performed in 6 patients due to negative PET at 60 min, with positive results in all cases, despite treatment with GC and/or biological therapy. In patients on GC therapy, delayed imaging protocols applying procedural recommendations for vascular quantification could improve diagnostic accuracy. Therefore, we suggest performing imaging only at 180 min in patients who have been on GCs for more than 3 days as well as in those with highly suspected GCA but negative findings in baseline PET at 60 min.

DWI scrolling artery sign for the diagnosis of giant cell arteritis: a pattern recognition approach

ObjectivesTo investigate the diagnostic accuracy of a pattern recognition approach for the evaluation of MRI scans of the head with diffusion-weighted imaging (DWI) in suspected giant cell arteritis (GCA).MethodsRetrospectively, 156...

The one-year infection risk among patients diagnosed with giant cell arteritis: use of antibiotics and hospitalisations

Abstract Objectives Patients with giant cell arteritis (GCA) primarily have their infections managed by primary care providers and hospitalisation is rarely necessary. Existing studies in GCA focus on infection-related hospitalisations only, whereas the use of antibiotic prescriptions is largely unknown. This study aims to examine the one-year overall infection risk among patients with GCA. Methods This nationwide observational cohort study included patients aged ≥50 years with a first-time GCA diagnosis in the Danish National Patient Registry (1996–2022). Patients with GCA were matched 1:10 by sex and date of birth with general population individuals and followed from date of diagnosis. Overall infections were defined as redeemed antibiotic prescriptions or infection-related hospitalisations. Utilising a pseudo-observation approach, we assessed 1-year cumulative incidence proportions (CIP), risk differences (RD) and relative risks (RR) of infections. Results The study included 17 773 incident patients with GCA and 177 730 reference individuals. Patients with GCA had a 1-year CIP of 52.4% (95% CI: 51.7–53.2) for overall infections and 17.6% (95% CI: 17.1–18.2) for infection-related hospitalisations. Compared with the reference cohort, patients with GCA had a RR of 1.40 (95% CI: 1.38–1.42) for overall infections and 2.71 (95% CI: 2.61–2.82) for infection-related hospitalisations. Additionally, higher cumulative glucocorticoid doses, advanced age (≥70 years) and higher comorbidity were associated with an increased risk of infections among patients with GCA. Conclusions The use of antibiotic prescriptions and infection-related hospitalisations in the first year after a GCA diagnosis is high compared with the background population. The cumulative glucocorticoid dose is associated with the infection risk.

Halo sign on temporal artery ultrasound versus temporal artery biopsy for giant cell arteritis.

Halo sign on temporal artery ultrasound versus temporal artery biopsy for giant cell arteritis.

Predictive Factors for Biopsy-Negative Giant Cell Arteritis and Alternative Diagnoses in a Neuro-Ophthalmology Context

ABSTRACT Giant cell arteritis is a challenging diagnosis for patients given the high prevalence of negative temporal artery biopsies (TAB). Despite the lack of histopathological evidence of giant cell arteritis in the TAB, patients can still have TAB-negative giant cell arteritis. The purpose of this paper is to analyse the predictors for TAB-negative giant cell arteritis and the alternative diagnosis of biopsy-negative patients without a giant cell arteritis diagnosis. A retrospective electronic database review of all TABs performed at the Royal Victorian Eye and Ear Hospital from February 2015 to May 2020. Logistic regression analysis was performed to determine predictive factors for a diagnosis of TAB-negative giant cell arteritis. In all cases, a clinical diagnosis of TAB-negative giant cell arteritis was determined by a neuro-ophthalmologist. Alternative diagnoses for negative TABs were identified and explored. A total of 368 TABs were analysed with 287 (78%) negative for histopathological evidence of GCA. Twenty-seven (9.4%) patients were diagnosed and treated as TAB-negative giant cell arteritis. The clinical predictors of a TAB-negative giant cell arteritis diagnosis were the presence of jaw claudication (OR 2.77, 95% CI 1.10–6.98) and CRP (OR 1.02, 95% CI 1.00–1.03). Alternative diagnoses included non-specific headache, non-arteritic anterior ischaemic optic neuropathy, retinal vessel occlusions, and ocular nerve palsies. Predictive factors for a diagnosis of TAB-negative giant cell arteritis were jaw claudication and an elevated CRP. Several alternative diagnoses can be considered for patients with a negative TAB in a neuro-ophthalmology context.

Associations between plasma metabolism associated proteins and future development of giant cell arteritis: results from a prospective study.

To investigate the relation between biomarkers associated with metabolism and subsequent development of giant cell arteritis (GCA). Participants in the population-based Malmö Diet Cancer Study (MDCS; N = 30447), who were subsequently diagnosed with GCA, were identified in a structured process. Matched GCA-free controls were selected from the study cohort. Baseline plasma samples were analyzed using the antibody-based OLINK proteomics metabolism panel (92 metabolic proteins). Analyses were pre-designated as hypothesis-driven or hypothesis-generating. In the latter, principal component analysis was used to identify groups of proteins that explain the variance in the proteome. There were 95 cases with a confirmed incident diagnosis of GCA (median 12.0 years after inclusion). Among biomarkers with a priori hypotheses, Adhesion G protein-coupled receptor E2 (ADGRE2) was positively associated (odds ratio (OR) per standard deviation (SD) 1.67; 95% CI 1.08-2.57), and Fructose-1,6-bisphosphatase 1 (FBP1) negatively associated (OR per SD 0.59; 95% CI 0.35-0.99) with GCA. In particular, ADGRE2 levels were associated with subsequent GCA in the subset sampled <8.5 years before diagnosis. For meteorin-like protein (Metrnl), the highest impact on the risk of GCA was observed in those sampled closest to diagnosis with a decreasing trend with longer time to GCA (p= 0.03). In the hypothesis generating analyses, elevated levels of receptor tyrosine-like orphan receptor 1 (ROR1) were associated with subsequent GCA. Biomarkers identified years before clinical diagnosis indicated a protective role of gluconeogenesis (FBP1) and an association with macrophage activation (ADGRE2 and Metrnl) and proinflammatory signals (ROR1) for development of GCA.

Association of Somatic TET2 Mutations With Giant Cell Arteritis.

Giant cell arteritis (GCA) is an age-related vasculitis. Prior studies have identified an association between GCA and hematologic malignancies (HMs). How the presence of somatic mutations that drive the development of HMs, or clonal hematopoiesis (CH), may influence clinical outcomes in GCA is not well understood. To examine an association between CH and GCA, we analyzed sequenced exomes of 470,960 UK Biobank (UKB) participants for the presence of CH and used multivariable Cox regression. To examine the clinical phenotype of GCA in patients with and without somatic mutations across the spectrum of CH to HM, we performed targeted sequencing of blood samples and electronic health record review on 114 patients with GCA seen at our institution. We then examined associations between specific clonal mutations and GCA disease manifestations. UKB participants with CH had a 1.48-fold increased risk of incident GCA compared to UKB participants without CH. GCA risk was highest among individuals with cytopenia (hazard ratio [HR] 2.98, P = 0.00178) and with TET2 mutation (HR 2.02, P = 0.00116). Mutations were detected in 27.2% of our institutional GCA cohort, three of whom had HM at GCA diagnosis. TET2 mutations were associated with vision loss in patients with GCA (odds ratio 4.33, P = 0.047). CH increases risk for development of GCA in a genotype-specific manner, with the greatest risk being conferred by the presence of mutations in TET2. Somatic TET2 mutations likewise increase the risk of GCA-associated vision loss. Integration of somatic genetic testing in GCA diagnostics may be warranted in the future.

Apolipoproteins and the risk of giant cell arteritis—a nested case–control study

BackgroundThe etiology of giant cell arteritis (GCA) and its predictors are incompletely understood. Previous studies have indicated reduced risk of future development of GCA in individuals with obesity and/or diabetes mellitus. There is limited information on blood lipids before the onset of GCA. The objective of the study was to investigate the relation between apolipoprotein levels and future diagnosis of GCA in a nested case–control analysis.MethodsIndividuals who developed GCA after inclusion in a population-based health survey (the Malmö Diet Cancer Study; N = 30,447) were identified by linking the health survey database to the local patient administrative register and the national patient register. A structured review of medical records was performed. Four controls for every validated case, matched for sex, year of birth, and year of screening, were selected from the database. Anthropometric measures, self-reported physical activity, based on a comprehensive, validated questionnaire, and non-fasting blood samples had been obtained at health survey screening. Concentrations of apolipoprotein A-I (ApoA-I) and apolipoprotein B (ApoB) in stored serum were measured using an immunonephelometric assay. Potential predictors of GCA were examined in conditional logistic regression models.ResultsThere were 100 cases with a confirmed clinical diagnosis of GCA (81% female; mean age at diagnosis 73.6 years). The median time from screening to diagnosis was 12 years (range 0.3–19.1). The cases had significantly higher ApoA-I at baseline screening compared to controls (mean 168.7 vs 160.9 mg/dL, odds ratio [OR] 1.57 per standard deviation (SD); 95% confidence interval [CI] 1.18–2.10) (SD 25.5 mg/dL). ApoB levels were similar between cases and controls (mean 109.3 vs 110.4 mg/dL, OR 0.99 per SD; 95% CI 0.74–1.32) (SD 27.1 mg/dL). The ApoB/ApoA1 ratio tended to be lower in cases than in controls, but the difference did not reach significance. The association between ApoA-I and GCA development remained significant in analysis adjusted for body mass index and physical activity (OR 1.48 per SD; 95% CI 1.09–1.99).ConclusionSubsequent development of GCA was associated with significantly higher levels of ApoA-I. These findings suggest that a metabolic profile associated with lower risk of cardiovascular disease may predispose to GCA.

Diagnostic accuracy of OGUS, Southend halo score and halo count in giant cell arteritis.

Ultrasound has a paramount role in the diagnostic assessment of giant cell arteritis (GCA); Southend halo score (HS), halo count (HC), and OMERACT GCA Ultrasonography Score (OGUS) are the first quantitative scores proposed in this setting. The aim of this study was therefore to assess the diagnostic accuracy of these scores in a real-life scenario, as well as to evaluate their optimal cutoff, also with respect to disease extent, sex, and age. We retrospectively collected clinical, serological, and US findings of all patients referred for the first time to our vasculitis clinic in the suspicion of GCA. A total of 79 patients were included, and a definite diagnosis of GCA was made in 43 patients. For OGUS, the ROC curve showed an optimal cut point of 0.81 (sensitivity 79.07% and specificity 97.22%). For HC and HS, the optimal cutoff values were > 1.5 (sensitivity 76.7% and specificity 97.2%) and > 14.5 (sensitivity 74.4% and specificity 97.2%), respectively. No relevant differences were assessed when patients were stratified according to disease extent, age, and sex. Compression sign (CS) was positive in 34 of 38 patients with cranial GCA and negative in all controls and LV-GCA. All three scores display good sensitivity and excellent specificity, although the cutoff was slightly different than proposed. In particular, for OGUS, a threshold of 0.81 could be employed for diagnostic purposes, although it was developed solely for monitoring. Due to its high sensitivity and specificity, CS should be always assessed in all patients referred with a suspicion of cranial GCA.

Combined Orbital and Cranial Vessel Wall Magnetic Resonance Imaging for the Assessment of Disease Activity in Giant Cell Arteritis.

Acute visual impairment is the most feared complication of giant cell arteritis (GCA) but is challenging to predict. Magnetic resonance imaging (MRI) evaluates orbital pathology not visualized by an ophthalmologic examination. This study combined orbital and cranial vessel wall MRI to assess both orbital and cranial disease activity in patients with GCA, including patients without visual symptoms. Patients with suspected active GCA who underwent orbital and cranial vessel wall MRI were included. In 14 patients, repeat imaging over 12 months assessed sensitivity to change. Clinical diagnosis of ocular or nonocular GCA was determined by a rheumatologist and/or ophthalmologist. A radiologist masked to clinical data scored MRI enhancement of structures. Sixty-four patients with suspected GCA were included: 25 (39%) received a clinical diagnosis of GCA, including 12 (19%) with ocular GCA. Orbital MRI enhancement was observed in 83% of patients with ocular GCA, 38% of patients with nonocular GCA, and 5% of patients with non-GCA. MRI had strong diagnostic performance for both any GCA and ocular GCA. Combining MRI with a funduscopic examination reached 100% sensitivity for ocular GCA. MRI enhancement significantly decreased after treatment (P < 0.01). In GCA, MRI is a sensitive tool that comprehensively evaluates multiple cranial structures, including the orbits, which are the most concerning site of pathology. Orbital enhancement in patients without visual symptoms suggests that MRI may detect at-risk subclinical ocular disease in GCA. MRI scores decreased following treatment, suggesting scores reflect inflammation. Future studies are needed to determine if MRI can identify patients at low risk for blindness who may receive less glucocorticoid therapy.

Ophthalmic giant cell arteritis in a patient with normal visual acuity

Abstract: In this study, we report a case of giant cell arteritis (GCA) and central retinal artery occlusion (CRAO) with cilioretinal artery sparing in a patient who presented with normal visual acuity and was treated with corticosteroids and tocilizumab. An 80-year-old male presented with restriction of his peripheral vision in the right eye along with fever, generalized headache, and jaw pain. His visual acuity was 20/20 in both eyes (OU) with an afferent pupillary defect in the right eye. Dilated fundoscopy revealed whitening of the retina around the vascular arcades with sparing of the central macula in the right eye, indicating CRAO sparing the cilioretinal artery. Laboratory evaluation revealed elevated inflammatory markers. The patient was treated initially with a pulse dose of intravenous corticosteroids, followed by an oral steroid taper, and he underwent a temporal artery biopsy (TAB). At 1-week follow-up, the patient reported improvement in his right eye visual symptoms. The TAB results confirmed the diagnosis of GCA, and the patient’s oral steroid was tapered with the addition of subcutaneous tocilizumab. One month later, the patient’s inflammatory markers returned to normal, and the patient’s vision remained stable. We conclude from this case that GCA may present with normal visual acuity, it can affect the central retinal artery without posterior ciliary artery involvement, and the combination of corticosteroids and subcutaneous tocilizumab may be an adequate treatment regimen.

Step forward towards treat-to-target management of giant cell arteritis: patients stratification aiming to targeted remission – updated guidelines

BackgroundThe aim of this work is to develop guidelines for health care professionals in the giant cell arteritis diagnosis and management, based on patients’ stratification and targeted outcome measures.ResultsFourteen expert panel had completed the two rounds surveys. After the end of round two, twenty three recommendations were released distributed on 8 domains. The percentage of the agreement on the recommendations was 76.9% to 100%. All 23 key questions were answered at the end of the second round with agreement upon.ConclusionPatient stratification facilitate the initiation of an appropriate management approach for patients with giant cell arteritis aiming at achieving targeted disease remission state and prevention of visual loss and/or development of ischaemic events. Treat to Target approach is a new concept in giant cell arteritis management which aims to provide tight control to achieve and maintain disease remission. This work defined the treatment targets in relation to the disease stage.

Use of ultrasound in diagnosis of giant cell arteritis (literature review and clinical case)

Giant cell arteritis (GCA) is the most common primary systemic vasculitis that usually occurs in adults over the age of 50. According to the classification, GCA refers to vasculitis with damage to large vessels (aorta and/or its main branches), however, both medium and small arteries can be involved in the process. Typical is the involvement of the temporal, visual, occipital, vertebrate, posterior ciliary arteries. Temporal artery biopsy has been considered as the ’gold standard’ for the diagnosis of GCA for a long time. However, this procedure is not always feasible in real clinical practice, because of the invasiveness of the method and certain technical difficulties. Currently, the cheapest, fastest and safest way to diagnose GCA is ultrasonography (US) examination of arteries (temporal arteries, other cranial and extracranial arteries), which is included in the new classification criteria for GCA. Thanks to the wider use of US of the arteries, over the past few years, the diagnosis of GCA has significantly improved, which affects the adequacy of therapy positively and, therefore, the patient's long-term prognosis. Standardization of the examination procedure is important, and the analysis of US-images should be carried out by a qualified specialist, which also requires special training. The review presents the necessary technical requirements, characteristics of the equipment and the methodology for conducting a US-study, determining US-finds during GCA. Thus, a personalized approach to the diagnosis of GCA, based on clinical manifestations, available instrumental imaging methods (primarily ultrasound), is optimal for the rapid diagnosis of HCA and treatment.

Reproducibility and accuracy of vessel wall MRI in diagnosing giant cell arteritis: a study with readers of varying expertise.

To evaluate the reproducibility of vessel wall magnetic resonance imaging (VW-MRI) in diagnosing giant cell arteritis (GCA) among groups of radiologists with varying levels of expertise. This institutional review board-approved retrospective single-center study recruited patients with suspected GCA between December 2014 and September 2021. Patients underwent 3-T VW-MRI before temporal artery biopsy. Ten radiologists with varying levels of expertise, blinded to all data, evaluated several intracranial and extracranial arteries to assess GCA diagnosis. Interobserver reproducibility and diagnostic performance were evaluated. Fifty patients (27 women and 23 men) with a mean age of 75.9 ± 9years were included. Thirty-one of 50 (62%) had a final diagnosis of GCA.VW-MRI had an almost perfect reproducibility among expert readers (kappa = 0.93; 95% CI 0.77-1) and substantial reproducibility among all readers, junior and non-expert senior readers (kappa = 0.7; 95% CI 0.66-0.73; kappa = 0.67 95% CI 0.59-0.74; kappa = 0.65; 95% CI 0.43-0.88 respectively) when diagnosing GCA. Substantial interobserver agreement was observed for the frontal branch of superficial temporal artery. Moderate interobserver agreement was observed for the superficial temporal artery and its parietal branch, as well as ophthalmic arteries in all groups of readers. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy varied depending on the group of readers. VW-MRI is a reproducible and accurate imaging modality for detecting GCA, even among less-experienced readers. This study advocates for the use of VW-MRI when diagnosing GCA even in less-experienced centers. VW-MRI is a reproducible and accurate imaging modality for detecting GCA, even among less-experienced readers, and it could be used as a first-line diagnostic tool for GCA in centers with limited expertise in GCA diagnosis. • Vessel wall magnetic resonance imaging (VW-MRI) is a reproducible and accurate imaging modality for detecting giant cell arteritis (GCA) in both extracranial and intracranial arteries. • The reproducibility of vessel wall magnetic resonance imaging for giant cell arteritis diagnosis was high among expert readers and moderate among less-experienced readers. • The use of vessel wall magnetic resonance imaging for giant cell arteritis diagnosis can be recommended even in centers with less-experienced readers.

Usefulness of 18F-FDG PET-CT for assessing large-vessel involvement in patients with suspected giant cell arteritis and negative temporal artery biopsy

ObjectiveTo investigate the usefulness of 18F-FDG PET-CT for assessing large-vessel (LV) involvement in patients with suspected giant cell arteritis (GCA) and a negative temporal artery biopsy (TAB).MethodsA retrospective review of our hospital databases was conducted to identify patients with suspected GCA and negative TAB who underwent an 18F-FDG PET-CT in an attempt to confirm the diagnosis. The gold standard for GCA diagnosis was clinical confirmation after a follow-up period of at least 12 months.ResultsOut of the 127 patients included in the study, 73 were diagnosed with GCA after a detailed review of their medical records.Of the 73 patients finally diagnosed with GCA, 18F-FDG PET-CT was considered positive in 61 cases (83.5%). Among the 54 patients without GCA, 18F-FDG PET-CT was considered positive in only eight cases (14.8%), which included 1 case of Erdheim-Chester disease, 3 cases of IgG4-related disease, 1 case of sarcoidosis, and 3 cases of isolated aortitis.Overall, the diagnostic performance of 18F-FDG PET-CT for assessing LV involvement in patients finally diagnosed with GCA and negative TAB yielded a sensitivity of 83.5%, specificity of 85.1%, and a diagnostic accuracy of 84% with an area under the ROC curve of 0.844 (95% CI: 0.752 to 0.936). The sensitivity was 89% in occult systemic GCA and 100% in extracranial LV-GCA.ConclusionOur study confirms the utility of 18F-FDG PET-CT in patients presenting with suspected GCA and a negative TAB by demonstrating the presence of LV involvement across different subsets of the disease.

Evaluation of baseline F-18 FDG positron emission tomography in the diagnosis and assessment of giant cell arteritis.

The aim of this study is to evaluate the baseline F18-FDG PET/CT findings of individuals diagnosed with giant cell arteritis (GCA) and to explore its association with clinical findings and classification criteria. We analysed data from patients who underwent F18-FDG PET/CT scans to investigate large vessel (LV) involvement between 2010 and 2019. Only patients with a clinical diagnosis of GCA and at least 6 months of follow-up were included. We compared initial clinical features and laboratory findings based on the presence of LV vasculitis on PET/CT and the maximum standard uptake value (SUVmax) of vascular territories. Twenty-nine patients (median age at diagnosis: 70, F/M: 24/5) were included in the study. Among them, 21 patients (72.4%) presented with cranial symptoms, while 8 patients (27.5%) had isolated LV-GCA. Twenty-two patients (75.9%) met the ACR/EULAR 2022 GCA classification criteria. LV vasculitis was detected on PET/CT in 23 patients (79.3%). A positive correlation was observed between SUVmax in the thoracic aorta and both CRP and ESR levels (r = 0.50, p = 0.026 and r = 0.63, p = 0.002, respectively). PET/CT positive patients were found to be younger (p = 0.016) and more frequently female (p = 0.017). They also exhibited fewer headaches (56.5% vs. 100%, p = 0.04), experienced fewer flares during follow-up (p = 0.03), and had a lower cumulative glucocorticoid dose at the 6th month (p = 0.036). Comparison of PET/CT-positive patients (n = 23) based on the fulfilment of the ACR/EULAR 2022 classification criteria revealed that patients who met these criteria were older (p = 0.02) and had significantly lower CRP levels at diagnosis (p = 0.02). The performance of F18-FDG PET/CT in diagnosing LV involvement in GCA is favourable, and the severity of FDG uptake in the vessel wall correlates with the acute phase response. Patients with extracranial involvement on PET/CT exhibit distinct features, including a younger age and female predominance. Additionally, these patients appear to experience fewer relapses and require lower doses of glucocorticoids. However, the clinical significance of PET/CT in patients who met ACR/EULAR classification criteria, predominantly consisting of patients with ischemic cranial symptoms, could not be determined in our study.