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[en] The CERN cryogenic facilities demand a versatile, distributed, homogeneous and highly reliable control system. For this purpose, CERN conceived and developed several frameworks (JCOP, UNICOS, FESA, CMW), based on current industrial technologies and COTS equipment, such as PC, PLC and SCADA systems complying with the requested constraints. The cryogenic control system nowadays uses these frameworks and allows the joint development of supervision and control layers by defining a common structure for specifications and code documentation. Another important advantage of the CERN frameworks is the possibility to integrate different control systems into a large technical system with communication capability. Such a system is capable of sharing control variables from all accelerator apparatus in order to cope with the operation scenarios.The first implementation of this control architecture started in 2000 for the Large Hadron Collider (LHC). Since then CERN continued developing the hardware and software components of the cryogenic control system, based on the exploitation of the experience gained. These developments are always aimed at increasing the safety and improving the performance. To overcome the long-term maintenance challenges, key strategies such as the use of homogeneous hardware solutions and the optimization of the maintenance procedures were set up. They are easing the development of the control applications and the hardware configuration by allowing a structured and homogeneous approach. Furthermore, they reduce the needed manpower and minimize the financial impact of the periodical maintenance. In that context, the standardization of technical solutions both at hardware and software level simplify also the systems monitoring the operation and maintenance processes, while providing a high level of availability.
[en] The application of multivariate techniques to experimental results requires a responsibility on behalf of the researcher to understand, evaluate and interpret their results, especially the ones that are more complex. The objective of this article is to evaluate the impact of three standardization techniques on the formation of clusters by means of the Kohonen neural network were studied. The standardization techniques studied were logarithm (log), generalized-log and improved minimum-maximum. The studies were performed using two different databases consisting of 298, named B1, and 146 samples, named B2. The B1 dataset is formed by samples that form two cluster very close. However, the B2 dataset form three different and separated cluster. The mass fractions of As, Ce, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Sc, Sm, Tb, Th, U, and Yb of each sample were determined by instrumental neutron activation analysis, INAA. Three validation indices : Jaccard, Fowlkes-Mallows and Rand were performed on the dataset. The results suggest that when the cluster are close, the improved minimum-maximum standardization is better than the logarithm and generalized-log. However, when the cluster are separated, the logarithm and generalized-log are better than the improved minimum-maximum technique. (author)
[en] Anomalous origin of the coronary arteries, though uncommon, is of great clinical concern. It can be the cause of sudden cardiac death and abnormal cardiac hemodynamics. Advances in electrocardiographically (ECG)-gated multi-detector CT have increased diagnostic accuracy in detecting anomalous origin of coronary arteries and their interarterial and intramural courses. Recent advances in multi-detector CT image processing software have allowed the creation of virtual endoluminal views of the aortic root and improved assessment of the intramural course (the length and relationship to the intercoronary commissure) of the coronary artery, which is of considerable surgical importance. We review our experience with virtual endoluminal imaging in our first 19 cases of interarterial coronary artery anomalies (17 cases of interarterial with intramural segment and 2 cases of purely interarterial course) diagnosed preoperatively and proven surgically.
[en] The authors compared measurements of hindfoot alignment on MR imaging with weight-bearing CT (WB-CT) to establish the degree of correlation. Forty-seven feet in 44 patients had weight-bearing CT and MRI studies performed on the same day. Hindfoot alignment on MRI was assessed by two radiologists who calculated tibiocalcaneal angle (TCA) and calcaneofibular ligament angle (CFLA). On WB-CT, foot ankle offset (FAO), calcaneal offset (CO) and hindfoot angle (HA) were assessed by a senior Foot and Ankle Surgeon using dedicated software. Pearson correlation coefficient was used to evaluate the correlation between these measurements. The study group comprised 27 males and 17 females with a mean age of 45 years (range 13–79 years). A statistically significant positive correlation was identified between TCA on MRI and all measurements of hindfoot alignment on WB-CT (p = 0.001–0.005). The CFLA on MRI only had significant correlation with CO on WB-CT (p = 0.03). A significant negative correlation was observed between both MRI parameters (p < 0.001). A highly significant correlation between tibiocalcaneal angle on non-weight-bearing ankle MR imaging and hindfoot alignment measurements on weight-bearing CT was identified.
[en] As well as nuclear power plants, research reactors are subject to a strict licensing process, requiring different studies to certify that the project is capable to safely withstand transients, without radiological consequences for people or environment. Thus, this work aims to develop a computational tool to investigate the behavior of MTR research reactors, including the Brazilian Multi-Purpose Reactor (RMB), by using a numerical-analytical approach for coupled thermohydraulic and neutronic analysis in a cooling subchannel. The modeling consists of the heat conduction equations on a fuel plate, the coolant energy transport equation in the subchannel and point kinetics equations with six groups of delayed neutrons. Improved lumped formulations are adopted for heat conduction in the transversal direction of the fuel and cladding, while the fluid energy equation is discretized along the subchannel by the finite difference method. The resulting system of ordinary differential equations is solved numerically by using the NDSolve function of the Mathematica software. The code is verified against the IAEA MTR 10 MW benchmark problems, showing good agreement with literature data. The Serpent 2 Monte Carlo code is employed to calculate the RMB kinetic parameters of the NPK equations and the steady state power distribution. The analysis results demonstrates that RMB operates safely under the events of loss of flow and reactivity insertion. (author)
[en] We aimed to compare the CT interpretation before and after the implementation of a computerized system for lung nodule detection and measurements in a nationwide lung cancer screening program. Our screening program started in April 2017, with 14 participating institutions. Initially, all CTs were interpreted using interpretation systems in each institution and manual nodule measurement (conventional system). A cloud-based CT interpretation system, equipped with semi-automated measurement and CAD (computer-aided detection) for lung nodules (cloud-based system), was implemented during the project. Positive rates and performances for lung cancer diagnosis based on the Lung-RADS version 1.0 were compared between the conventional and cloud-based systems. A total of 1821 (M:F = 1782:39, mean age 62.7 years, 16 confirmed lung cancers) and 4666 participants (M:F = 4560:106, mean age 62.8 years, 31 confirmed lung cancers) were included in the conventional and cloud-based systems, respectively. Significantly more nodules were detected in the cloud-based system (0.76 vs. 1.07 nodule/participant, p < .001). Positive rate did not differ significantly between the two systems (9.9% vs. 11.0%, p = .211), while their variability across institutions was significantly lower in the cloud-based system (coefficients of variability, 0.519 vs. 0.311, p = .018). The Lung-RADS-based sensitivity (93.8% vs. 93.5%, p = .979) and specificity (90.9% vs. 89.6%, p = .132) did not differ significantly between the two systems. Implementation of CAD and semi-automated measurement for lung nodules in a nationwide lung cancer screening program resulted in increased number of detected nodules and reduced variability in positive rates across institutions.
[en] To compare the diagnostic accuracy (ACC) in the detection of acute posterior circulation strokes between qualitative evaluation of software-generated colour maps and automatic assessment of CT perfusion (CTP) parameters. Were retrospectively collected 50 patients suspected of acute posterior circulation stroke who underwent to CTP (GE "Lightspeed", 64 slices) within 24 h after symptom onset between January 2016 and December 2018. The Posterior circulation-Acute Stroke Prognosis Early CT Score (pc-ASPECTS) was used for quantifying the extent of ischaemic areas on non-contrast (NC)CT and colour-coded maps generated by CTP4 (GE) and RAPID (iSchemia View) software. Final pc-ASPECTS was calculated on follow-up NCCT and/or MRI (Philips Intera 3.0 T or Philips Achieva Ingenia 1.5 T). RAPID software also elaborated automatic quantitative mismatch maps. By qualitative evaluation of colour-coded maps, MTT-CTP4D and Tmax-RAPID showed the highest sensitivity (SE) (88.6% and 90.9%, respectively) and ACC (84% and 88%, respectively) compared with the other perfusion parameters (CBV, CBF). Baseline NCCT and CBF provided by RAPID quantitative perfusion mismatch maps had the lowest SE (29.6% and 6.8%, respectively) and ACC (38% and 18%, respectively). CBF and Tmax assessment provided by quantitative RAPID perfusion mismatch maps showed significant lower SE and ACC than qualitative evaluation. No significant differences were found between the pc-ASPECTSs assessed on colour-coded MTT and Tmax maps neither between the scores assessed on colour-coded CBV-CTP4D and CBF-RAPID maps. Qualitative analysis of colour-coded maps resulted more sensitive and accurate in the detection of ischaemic changes than automatic quantitative analysis.
[en] The objective of this study was to evaluate whether Ga-PSMA PET/CT whole-body tumor burden (PSMAwbtb) is associated with clinical parameters and laboratory parameters in prostate cancer patients. We retrospectively evaluated prostate cancer patients submitted to PSMA PET/CT for primary staging purposes or due to biochemical recurrence (BR). PSMAwbtb metrics (total volume of PSMA-avid tumor (PSMA-TV)) and total uptake of PSMA-avid lesions (PSMA-TL) were calculated semi-automatically. Spearman’s rank correlations between PSMAwbtb metrics and clinical, laboratory parameters (age, time-to-BR, years of diagnosis of prostate cancer, free and total serum PSA levels, and the Gleason score) and with the highest SUVmax of a lesion (hSUVmax) were analyzed. Among the 257 PSMA PET/CT studies, there were 46 scans (17.9%) performed for primary staging and 211 (82.1%) for BR. PSMA-TV and PSMA-TL were calculated for the 157 positive scans (58.8%), which were 43 patients (93.5%) in the primary staging group and 114 patients (54.0%) in the BR group. In the primary staging group, we observed a significant correlation between PSMA-TL and hSUVmax (p = 0.0021). In the BR group, there was a significant direct correlation between PSMA-TL and the variables age (p = 0.0031), total serum PSA values (p = < 0.0001), free serum PSA values (p = < 0.0001), and the hSUVmax (p = < 0.0001). Similar results were obtained for PSMA-TV. PSMAwbtb has a direct and positive correlation with serum PSA values and age in prostate cancer patients with BR.
[en] To investigate the ability of F-FDG PET/CT to assess the response of patients with metastatic melanoma to immunotherapy. A comprehensive search of the literature for studies examining the prognostic value of F-FDG PET/CT in monitoring the response of patients with metastatic melanoma to immunotherapy was performed. We also screened the references of the selected articles to identify any other relevant studies. Detailed data were extracted and categorized. Comprehensive meta-analysis software was used for analysis. Twenty four eligible articles were included in the systematic review. Based on the baseline F-FDG PET/CT imaging, the pooled hazard ratios of MTV, SLR, SUV/SULmax, SUV/SULpeak, and TLG for overall survival (OS) were 1.777 (95%CI: 1.389–2.275, p < 0.001), 3.425 (95%CI: 1.707–6.869, p = 0.001), 0.941 (95%CI: 0.599–1.477, p = 0.791), 1.704 (95%CI: 1.253–2.316, p = 0.016), and 1.755 (95%CI: 1.315–2.342, p < 0.001), respectively. The conventional and modified response assessment criteria exhibited a pooled sensitivity of 64% (95%CI: 46–79%) and 94% (95%CI: 81–99%) and a pooled specificity of 80% (95%CI: 59–93%) and 84% (95%CI: 64–95%), respectively, for the early 18F-FDG PET/CT scan. On the other hand, based on the late F-FDG PET/CT scan, the pooled sensitivity of 67% (95%CI: 35–90%) and 92% (95%CI: 73–99%) and pooled specificity of 77% (95%CI: 56–91%) and 76% (95%CI: 50–93%) were observed for the conventional and modified criteria, respectively. PET-detectable immune-related adverse events (irAEs) were associated with the response to therapy. The baseline SUVpeak, MTV, and TLG parameters represent promising predictors of the final response of metastatic melanoma patients to immunotherapy. Modified response assessment criteria are potentially an appropriate method for monitoring immunotherapy. irAEs are also valuable for predicting eventual clinical benefit of treatment.
[en] To construct and validate a nomogram model that integrated the CT radiomic features and the TNM staging for risk stratification of thymic epithelial tumors (TETs). A total of 136 patients with pathology-confirmed TETs who underwent CT examination were collected from two institutions. According to the WHO pathological classification criteria, patients were classified into low-risk and high-risk groups. The TNM staging was determined in terms of the 8th edition AJCC/UICC staging criteria. LASSO regression was performed to extract the optimal features correlated to risk stratification among the 704 radiomic features calculated. A nomogram model was constructed by combining the Radscore and the TNM staging. The clinical performance was evaluated by ROC analysis, calibration curve, and decision curve analysis (DCA). The Kaplan-Meier (KM) analysis was employed for survival analysis. Five optimal features identified by LASSO regression were employed to calculate the Radscore correlated to risk stratification. The nomogram model showed a better performance in both training cohort (AUC = 0.84, 95%CI 0.75–0.91) and external validation cohort (AUC = 0.79, 95%CI 0.69–0.88). The calibration curve and DCA analysis indicated a better accuracy of the nomogram model for risk stratification than either Radscore or the TNM staging alone. The KM analysis showed a significant difference between the two groups stratified by the nomogram model (p = 0.02). A nomogram model that integrated the radiomic signatures and the TNM staging could serve as a reliable model of risk stratification in predicting the prognosis of patients with TETs.