Role of FDG-PET/CT in children with fever of unknown origin

PURPOSE: To determine the role of 18F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)/computed tomography (CT) in children with fever of unknown origin (FUO). METHODS: This retrospective single-center study included 110 children (0-18 years) with FUO who underwent FDG-PET/CT between 2010 and 2019. The diagnostic value of FDG-PET/CT for identifying cause of fever was calculated, treatment modifications after FDG-PET/CT were assessed, and logistic regression analyses were performed to identify clinical and biochemical factors associated with FDG-PET/CT outcome. RESULTS: In 53 out of 110 patients (48%), FDG-PET/CT identified a (true positive) cause of fever. Endocarditis (11%), systemic juvenile idiopathic arthritis (5%), and inflammatory bowel disorder (5%) were the most common causes of FUO. In 42 patients (38%), no cause of fever was found on FDG-PET/CT. In 58 out of 110 patients (53%), treatment modifications were made after FDG-PET/CT. FDG-PET/CT achieved a sensitivity of 85.5%, specificity of 79.2%, positive predictive value of 84.1%, and negative predictive value of 80.9%. On multivariate logistic regression, C-reactive protein was positively associated with finding a true positive focus of fever on FDG-PET/CT (OR = 1.01 (95% CI 1.00-1.02) per mg/L increase in CRP), while leukocyte count was negatively associated with finding a true positive focus of fever (OR = 0.91 (95% CI 0.85-0.97) per 109 leukocytes/L increase). CONCLUSION: FDG-PET/CT is a valuable diagnostic tool in the evaluation of children with FUO, since it may detect a true underlying cause in almost half (48%) of all cases where none was found otherwise. It allows full-body evaluation in patients without disease-specific symptoms on one examination. CRP and leukocyte count were significantly associated with FDG-PET/CT results, which may contribute to a priori assessment on the outcome of FDG-PET/CT. Future research could be aimed at evaluating more patient-specific factors to prospectively estimate the added value of FDG-PET/CT in children with FUO

Differences in presentation between paediatric- and adult-onset primary Sjögren's syndrome patients

OBJECTIVES: Primary Sjögren's syndrome (pSS) is a rare disease in paediatric patients. Presenting symptoms differ from those in adult patients. The aim of this study was to evaluate presenting symptoms, classification criteria and clinical assessments, including salivary gland ultrasonography (SGUS), at disease onset in paediatric and adult patients with pSS. METHODS: Data of 23 paediatric- and 33 adult-onset patients with pSS were obtained from our standardised multidisciplinary REpSULT and RESULT cohorts, respectively. Clinical, patient-reported, serological, functional, biopsy and SGUS parameters were compared. RESULTS: In paediatric-onset pSS (pedSS) patients, recurrent parotid gland swelling (91% vs. 49%, p<0.001) and fever (30% vs. 3%, p=0.006) were more often present than in adult-onset patients. In contrast, sicca symptoms of mouth (52% vs. 79%, p=0.046) and eyes (26% vs. 73%, p<0.001) were less common in pedSS patients. In paediatric patients, the entry criteria of the ACR/EULAR classification were most often met due to activity in the glandular domain of the ESSDAI. When applying the ACR/EULAR classification criteria, only 78% of pedSS fulfilled these criteria compared to 100% of adult patients. Abnormal glandular function tests had a greater contribution to fulfilling the criteria in adults, while the biopsy had a greater contribution in paediatric patients. Anti-SSA/Ro serology had similar contribution for both cohorts. SGUS Hocevar score was significantly higher in paediatric compared to adult patients (median 25 vs. 18, p=0.004). CONCLUSION: PedSS has a different presentation than adult-onset pSS. Recurrent parotid gland swelling in paediatric patients should alert clinicians to the potential presence of pSS

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde