Large Vessel Vasculitis

2-[18F] fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) has become part of the worldwide standard of care in oncology. For a decade, this functional imaging tool has also demonstrated important diagnostic results in inflammatory diseases, especially in large vessel vasculitis (LVV). Since clinical PET imaging is increasingly used in these two conditions, this chapter aims to assist imaging specialists and clinicians by getting acquainted with the PET imaging procedures and the current status in clinical practice for LVV. General background information, PET technical considerations (including patient preparation, imaging protocols, scoring methodology), diagnostic and prognostic performance, and response monitoring will be addressed, in line with recent international expert-based recommendations.Also, in the era of personalized medicine, new hybrid technologies such as PET/MR and PET radiotracers will be discussed.</sub

Need and value of targeted immunosuppressive therapy in giant cell arteritis

Despite the heterogeneity of the giant cell arteritis (GCA) at the level of clinical manifestations and the cellular and molecular players involved in its pathogenesis, GCA is still treated with standardised regimens largely based on glucocorticoids (GC). Long-term use of high dosages of GC as required in GCA are associated with many clinically relevant side effects. In the recent years, the interleukin-6 receptor blocker tocilizumab has become available as the only registered targeted immunosuppressive agent in GCA. However, immunological heterogeneity may require different pathways to be targeted in order to achieve a clinical, immunological and vascular remission in GCA. The advances in the targeted blockade of various molecular pathways involved in other inflammatory and autoimmune diseases have catalyzed the research on targeted therapy in GCA. This article gives an overview of the studies with targeted immunosuppressive treatments in GCA, with a focus on their clinical value, including their effects at the level of vascular inflammation

A usability study of physiological measurement in school using wearable sensors

Measuring psychophysiological signals of adolescents using unobtrusive wearable sensors may contribute to understanding the development of emotional disorders. This study investigated the feasibility of measuring high quality physiological data and examined the validity of signal processing in a school setting. Among 86 adolescents, a total of more than 410 h of electrodermal activity (EDA) data were recorded using a wrist-worn sensor with gelled electrodes and over 370 h of heart rate data were recorded using a chest-strap sensor. The results support the feasibility of monitoring physiological signals at school. We describe specific challenges and provide recommendations for signal analysis, including dealing with invalid signals due to loose sensors, and quantization noise that can be caused by limitations in analog-to-digital conversion in wearable devices and be mistaken as physiological responses. Importantly, our results show that using toolboxes for automatic signal preprocessing, decomposition, and artifact detection with default parameters while neglecting differences between devices and measurement contexts yield misleading results. Time courses of students' physiological signals throughout the course of a class were found to be clearer after applying our proposed preprocessing steps

Visual and semiquantitative assessment of cranial artery inflammation with FDG-PET/CT in giant cell arteritis

BACKGROUND AND AIM: Assessing cranial artery inflammation plays an important role in the diagnosis of cranial giant cell arteritis (C-GCA). However, current diagnostic tests are limited. The use of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT imaging is an established tool for assessing large vessel inflammation but is currently not used for assessment of the cranial arteries. This study aimed to evaluate the accuracy of FDG-PET/CT in the diagnosis of biopsy proven C-GCA and its relation to clinical presentation. METHODS: This retrospective case control study included temporal artery biopsy (TAB) positive C-GCA patients and age- and sex-matched controls. FDG-PET/CT scans were performed according to EANM/EARL guidelines, visually assessed by an experienced nuclear medicine physician, and semiquantitatively assessed using the maximum standardised uptake value (SUVmax). The visual and semiquantitative assessments were performed on the temporal arteries, maxillary arteries, vertebral arteries, and occipital arteries. Clinical signs and symptoms were scored for comparison. RESULTS: A total of 24 C-GCA patients and 24 controls were included in the study. Visual analysis revealed an 83% sensitivity and a 75% specificity. Receiver operating characteristic (ROC) analysis of the semiquantitative assessment revealed a 79% sensitivity and a 92% specificity when measuring SUVmax in the cranial arteries. Visual and semiquantitative assessments showed moderate agreement (Fleiss kappa 0.55). There was a positive correlation between the number of cranial symptoms and the SUVmax in the vertebral artery. CONCLUSION: FDG-PET/CT can reliably diagnose C-GCA by assessing cranial artery inflammation using SUVmax. Extending the use of FDG-PET/CT to include assessment of the cranial arteries may improve its diagnostic value in GCA and provide a suitable alternative to TAB. Moderate agreement between visual and semiquantitative assessment methods suggest diagnostic accuracy may be improved by further standardisation