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Background Coronary artery calcium is a well-known predictor of major adverse cardiac events and is usually scored manually from dedicated, ECG-triggered calcium scoring CT (CSCT) scans. In clinical practice, a myocardial perfusion PET scan is accompanied by a non-ECG triggered low dose CT (LDCT) scan. In this study, we investigated the accuracy of patients’ cardiovascular risk categorisation based on manual, visual, and automatic AI calcium scoring using the LDCT scan. Methods We retrospectively enrolled 213 patients. Each patient received a 13N-ammonia PET scan, an LDCT scan, and a CSCT scan as the gold standard. All LDCT and CSCT scans were scored manually, visually, and automatically. For the manual scoring, we used vendor recommended software (Syngo.via, Siemens). For visual scoring a 6-points risk scale was used (0; 1-10; 11-100; 101-400; 401-100; > 1 000 Agatston score). The automatic scoring was performed with deep learning software (Syngo.via, Siemens). All manual and automatic Agatston scores were converted to the 6-point risk scale. Manual CSCT scoring was used as a reference. Results The agreement of manual and automatic LDCT scoring with the reference was low [weighted kappa 0.59 (95% CI 0.53-0.65); 0.50 (95% CI 0.44-0.56), respectively], but the agreement of visual LDCT scoring was strong [0.82 (95% CI 0.77-0.86)]. Conclusions Compared with the gold standard manual CSCT scoring, visual LDCT scoring outperformed manual LDCT and automatic LDCT scoring.

Objectives The current study aimed to design an ultra-low-dose CT examination protocol using a deep learning approach suitable for clinical diagnosis of COVID-19 patients. Methods In this study, 800, 170, and 171 pairs of ultra-low-dose and full-dose CT images were used as input/output as training, test, and external validation set, respectively, to implement the full-dose prediction technique. A residual convolutional neural network was applied to generate full-dose from ultra-low-dose CT images. The quality of predicted CT images was assessed using root mean square error (RMSE), structural similarity index (SSIM), and peak signal-to-noise ratio (PSNR). Scores ranging from 1 to 5 were assigned reflecting subjective assessment of image quality and related COVID-19 features, including ground glass opacities (GGO), crazy paving (CP), consolidation (CS), nodular infiltrates (NI), bronchovascular thickening (BVT), and pleural effusion (PE). Results The radiation dose in terms of CT dose index (CTDIvol) was reduced by up to 89%. The RMSE decreased from 0.16 ± 0.05 to 0.09 ± 0.02 and from 0.16 ± 0.06 to 0.08 ± 0.02 for the predicted compared with ultra-low-dose CT images in the test and external validation set, respectively. The overall scoring assigned by radiologists showed an acceptance rate of 4.72 ± 0.57 out of 5 for reference full-dose CT images, while ultra-low-dose CT images rated 2.78 ± 0.9. The predicted CT images using the deep learning algorithm achieved a score of 4.42 ± 0.8. Conclusions The results demonstrated that the deep learning algorithm is capable of predicting standard full-dose CT images with acceptable quality for the clinical diagnosis of COVID-19 positive patients with substantial radiation dose reduction. Key Points • Ultra-low-dose CT imaging of COVID-19 patients would result in the loss of critical information about lesion types, which could potentially affect clinical diagnosis. • Deep learning–based prediction of full-dose from ultra-low-dose CT images for the diagnosis of COVID-19 could reduce the radiation dose by up to 89%. • Deep learning algorithms failed to recover the correct lesion structure/density for a number of patients considered outliers, and as such, further research and development is warranted to address these limitations.

Our ability to examine genetic variation across entire genomes has enabled many studies searching for the genetic basis of local adaptation. These studies have identified numerous loci as candidates for differential local selection; however, relatively few have examined the overlap among candidate loci identified from independent studies of the same species in different geographic areas or evolutionary lineages. We used an allelotyping approach with a 220K SNP array to characterize the population genetic structure of Atlantic salmon in north-eastern Europe and ask whether the same genomic segments emerged as outliers among populations in different geographic regions. Genome-wide data recapitulated the phylogeographic structure previously inferred from mtDNA and microsatellite markers. Independent analyses of three genetically and geographically distinct groups of populations repeatedly inferred the same 17 haploblocks to contain loci under differential local selection. The most strongly supported of these replicated haploblocks had known strong associations with life-history variation or immune response in Atlantic salmon. Our results are consistent with these genomic segments harbouring large-effect loci which have a major role in Atlantic salmon diversification and are ideal targets for validation studies.

Ett stridsledningssystem fungerar som ett maskinellt stöd för manövrering och kontroll över trupper. Det är via det systemet information ges och eftersom den informationen innehåller hemlig — och viktig — data är det angeläget att den datan är pålitlig. En grundläggande del i utveckling och underhåll av sådana system är att utföra sårbarhetsskanningar och att konfigureringskrav uppfylls så säkra dataförbindelser upprätthålls. Med teknikutvecklingen upptäcks ständigt nya sårbarheter som kan utnyttjas för att ta sig in i ett system vilket ställer nya krav för systemets säkerhet. Genom automatiserade tester sker skanningen kontinuerligt vilket upprätthåller säkerheten i systemet. Två exempel på verktyg som förenklar denna skanningsprocess är Nessus och Tenable.sc, där Nessus utför de aktuella skanningarna och Tenable.sc tillhandahåller ett effektivt gränssnitt för skanningens analys. Denna rapport undersöker skanningsförfarandet på stridsledningssystemet ASTERIX Intag Försvarsmakten (AIF). Det är ett system med fyra servrar där radardata hämtas från Luftfartsverkets nätverk och skickas vidare till försvarsmaktens nätverk. I systemet finns brandväggar medmycketstrikta regler som gör att en skanning inte går att automatisera utan att äventyra den säkerhet som redan är implementerad. Genom att virtualisera AIF kan en annan virtuell maskin få åtkomst till systemet vilket gör en automatiserad skanning genomförbar. Den virtuella maskinen fungerar som en skanningsdator där Nessus och Tenable.sc installeras och som skanningen utgår ifrån. All kommunikation med verktygen hanteras med ett pythonskript för att exempelvis starta en skanning eller ladda ner en rapport där tillgången till servrarna ges via Secure Shell (SSH) när skanningen ska utföras. Att automatisera skanningen i virtualiserade miljöer gör testningsprocessen skalbar. Det möjliggör automatiserade masstester vilket kan användas som ett verktyg för en sårbarhetsanalys, och som i sin tur bidrar och upprätthåller en mer säker IT-infrastruktur. A command and control system serves as a support for maneuvering and control of troops. It is through that system information is given and since the information contains confidential — and significant — data, it is important that the data is reliable. A fundamental part in the development and maintenance of such systems are to perform vulnerability scans and that configuration requirements are met so that secure data connections are maintained. With technological development, new vulnerabilities are constantly being discovered that can be used to break into a system, which places new demands on the system’s security. Through automated tests, the scanning takes place continuously, which maintains the security of the system. Two examples on tools that simplify this scanning process are Nessus and Tenable.sc, where Nessus performs the actual scans and Tenable.sc provides one effective interface for scanning analysis. This report examines the scanning procedure on the command and control system AIF. It is a system with four servers where radar data is retrieved from the Civil Aviation Administration’s (Luftfartsverket) network and forwarded to the Armed Forces’ (Försvarsmaktens) network. The system has firewalls with very strict rules that make the automation of the scan impossible without compromising the security that already been implemented. By virtualizing AIF, another virtual machine can access the system, making an automated scan feasible. The virtual machine functions as a scanning computer where Nessus and Tenable.sc are installed and on which the scanning is based. All communication with the tools is handled with a python script to, for example, start a scan or download a report where access to the servers is given via Secure Shell (SSH) when the scan is to be performed. Automating scanning in virtualized environments makes the testing process a scalable one. It enables automated mass testing, which can be used as a tool for a vulnerability analysis, and which in turn contributes to and maintains a more secure IT infrastructure.

The potential of covert pulmonary arteriovenous malformations (PAVMs) to cause early onset, preventable ischemic strokes is not well known to neurologists. This is evident by their lack of mention in serial American Heart Association/ American Stroke Association (AHA/ASA) Guidelines, and the single case-report biased literature of recent years. To inform, we performed PubMed and Cochrane database searches for major studies on ischemic stroke and PAVMs published from January 1, 1974 through April 3, 2021. This identified twenty-four major observational studies, three societal guidelines, one nationwide analysis, three systematic reviews, twenty-one other review/opinion articles, and eighteen recent (2017-2021) case-reports/series that were synthesized. Key points are that patients with PAVMs suffer ischemic stroke a decade earlier than routine stroke, losing nine extra healthy-life-years per patient in the recent US nationwide analysis (2005-2014). Large-scale thoracic CT screens of the general population in Japan estimate PAVM prevalence to be 38/100,000 (95% confidence interval 18-76), with ischemic stroke rates exceeding 10% across PAVM series dating back to the 1950s, with most PAVMs remaining undiagnosed until the time of clinical stroke. Notably, the rate of PAVM diagnoses doubled in US ischemic stroke hospitalizations between 2005-2014. The burden of silent cerebral infarction approximates to twice that of clinical stroke. Over 80% patients have underlying hereditary hemorrhagic telangiectasia (HHT). The predominant stroke mechanism is paradoxical embolization of platelet-rich emboli, with iron-deficiency emerging as a modifiable risk-factor. PAVM related ischemic strokes may be cortical or subcortical, but very rarely cause proximal large vessel occlusions. Single antiplatelet therapy maybe effective for secondary stroke prophylaxis, with dual antiplatelet or anticoagulation therapy requiring nuanced risk-benefit analysis given their risk of aggravating iron deficiency. In conclusion, this review summarizes the current ischemic stroke burden from PAVMs, the implicative pathophysiology, and relevant diagnostic and treatment overviews to facilitate future incorporation into AHA/ASA guidelines.

The central Australian ant Melophorus bagoti is the most thermophilic ant in Australia and forages solitarily in the summer months during the hottest period of the day. For successful navigation, desert ants of many species are known to integrate a path and learn landmark cues around the nest. Ants perform a series of exploratory walks around the nest before their first foraging trip, during which they are presumed to learn about their landmark panorama. Here, we studied 15 naive M. bagoti ants transitioning from indoor work to foraging outside the nest. In 3–4 consecutive days, they performed 3–7 exploratory walks before heading off to forage. Naive ants increased the area of exploration around the nest and the duration of trips over successive learning walks. In their first foraging walk, the majority of the ants followed a direction explored on their last learning walk. During learning walks, the ants stopped and performed stereotypical orientation behaviours called pirouettes. They performed complete body rotations with stopping phases as well as small circular walks without stops known as voltes. After just one learning walk, these desert ants could head in the home direction from locations 2 m from the nest, although not from locations 4 m from the nest. These results suggest gradual learning of the visual landmark panorama around the foragers’ nest. Our observations show that M. bagoti exhibit similar characteristics in their learning walks to other desert ants of the genera Ocymyrmex and Cataglyphis., Summary: Before becoming foragers, Melophorus bagoti ants took 3–7 learning walks around their nest. They increased the duration and area explored over successive walks, stopping occasionally to scan the environment.

Background: Asthma is a disease characterized by ventilation heterogeneity (VH). A number of studies have demonstrated that VH markers derived by using impulse oscillometry (IOS) or multiple-breath washout (MBW) are associated with key asthmatic patient related outcome measures and airways hyperresponsiveness. However, the topographical mechanisms of VH in the lung remain poorly understood.Objectives: We hypothesized that specific regionalization of topographical small-airway disease would best account for IOS- and MBW-measured indices in patients.Methods: We evaluated the results of paired expiratory/inspiratory computed tomography in a cohort of asthmatic (n = 41) and healthy (n = 11) volunteers to understand the determinants of clinical VH indices commonly reported by using IOS and MBW. Parametric response mapping (PRM) was used to calculate the functional small-airways disease marker PRMfSAD and Hounsfield unit (HU)-based density changes from total lung capacity to functional residual capacity (Delta HU); gradients of Delta HU in gravitationally perpendicular (parallel) inferior-superior (anterior-posterior) axes were quantified.Results: The Delta HU gradient in the inferior-superior axis provided the highest level of discrimination of both acinar VH (measured by using phase 3 slope analysis of multiple-breath washout data) and resistance at 5 Hz minus resistance at 20 Hz measured by using impulse oscillometry (R5-R20) values. Patients with a high inferior-superior Delta HU gradient demonstrated evidence of reduced specific ventilation in the lower lobes of the lungs and high levels of PRMfSAD. A computational small-airway tree model confirmed that constriction of gravitationally dependent, lower-zone, small airway branches would promote the largest increases in R5-R20 values. Ventilation gradients correlated with asthma control and quality of life but not with exacerbation frequency.Conclusions: Lower lobe predominant small-airways disease is a major driver of clinically measured VH in adults with asthma.

Traumatic brain injury is a complex and diverse medical condition with a high frequency of intracranial abnormalities. These can typically be visualized on a computed tomography (CT) scan, which provides important information for further patient management, such as the need for operative intervention. In order to quantify the extent of acute intracranial lesions and associated secondary injuries, such as midline shift and cisternal compression, visual assessment of CT images has limitations, including observer variability and lack of quantitative interpretation. Automated image analysis can quantify the extent of intracranial abnormalities and provide added value in routine clinical practice. In this article, we present icobrain, a fully automated method that reliably computes acute intracranial lesions volume based on deep learning, cistern volume, and midline shift on the noncontrast CT image of a patient. The accuracy of our method is evaluated on a subset of the multi-center data set from the CENTER-TBI (Collaborative European Neurotrauma Effectiveness Research in Traumatic Brain Injury) study for which expert annotations were used as a reference. Median volume differences between expert assessments and icobrain are 0.07 mL for acute intracranial lesions and -0.01 mL for cistern segmentation. Correlation between expert assessments and icobrain is 0.91 for volume of acute intracranial lesions and 0.94 for volume of the cisterns. For midline shift computations, median error is -0.22 mm, with a correlation of 0.93 with expert assessments. ispartof: JOURNAL OF NEUROTRAUMA vol:36 issue:11 pages:1794-1803 ispartof: location:United States status: published

Aim: To estimate the standard uptake values (SUVs) of Tc-99m methylene-diphosphonate (Tc-99m MDP) from normal skeletal sites in breast cancer patients using quantitative single-photon emission computed tomography (SPECT).Materials and Methods: A total of 60 breast cancer patients who underwent Tc-99m MDP SPECT/CT study at different postinjection acquisition times were included in this study. Based on postinjection acquisition time, patients were divided into four study groups (n_15 each), i.e. I st (2 h), II nd (3 h), III rd (4 h), and IV th (5 h). Image quantification (SUVmax and SUVmean) was performed using Q.Metrix software. Delineation of volume of interest was shaped around different bones of the skeletal system. Results: The highest normal SUVmax and SUVmean values were observed in lumber and thoracic vertebra (8.89 ± 2.26 and 2.89 ± 0.58) for Group I and in pelvis and thoracic (9.6 ± 1.32 and 3.04 ± 0.64), (10.93 ± 3.91 and 3.65 ± 0.97), (11.33 ± 2.67 and 3.65 ± 0.22) for Group II, III and IV, respectively. Lowest normal SUVmax and SUVmean values were observed in humerus and ribs (3.22 ± 0.67 and 0.97 ± 0.18), (5.16 ± 1.82 and 1.18 ± 0.16) for Group I, IV, and in humerus (3.17 ± 0.58 and 0.85 ± 0.26), (3.98 ± 1.12 and 1.04 ± 0.28) for Group II and III, respectively. Significant difference ( P < 0.05) noted in SUVmax for sternum, cervical, humerus, ribs, and pelvis with respect to time. However, significant difference ( P < 0.05) noted in SUVmean for all skeletal sites with respect to time. Conclusions: Our study shows variability in normal SUV values for different skeletal sites in breast cancer patients. Vertebral bodies and pelvis contribute highest SUV values. Time dependency of SUVs emphasizes the usefulness of routinely acquired images at the same time after Tc-99m MDP injection, especially in follow-up studies.

Les recherches en neurosciences utilisant des sets de photographies d’expression faciale afin de tester, à l’aide des techniques d’imageries, les réactions émotionnelles des adolescent-e-s ont participé à établir un modèle neurobiologique de l’adolescence. Ce modèle, qui postule que la configuration cérébrale particulière à cette période de la vie soumet les jeunes personnes à un déficit de contrôle émotionnel, tend à s’imposer dans le domaine des sciences de l’adolescence, particulièrement en lien avec la question des prises de risque. Cet article propose d’investiguer le processus par lequel les neurosciences cognitives ont produit, à partir de portraits photographiques d’acteurs mimant des émotions, des stimuli valides qui permettent de rendre visible par le biais de l’IRMf une différence cérébrale discriminant d’une part les adolescent-e-s et les adultes et d’autre part les jeunes filles et les jeunes garçons dans la gestion de l’information émotionnelle. En effet, le cerveau émotionnel adolescent est construit selon deux hiérarchies enchâssées : si la différence d’âge fait figure de hiérarchie fondatrice, celle de sexe constitue un élément tantôt moteur tantôt modérateur à l’intérieur de celle-ci. Neuroscience research using sets of pictures of facial affect to test the emotional reactions of teenagers with fMRI has participated to construct a neurobiological model of adolescence. This model postulates that the particular brain configuration of young people indicates a lack of emotional control. This model tends to prevail in the sciences of adolescence, particularly in connection with the issue of risk taking. This paper investigates the process by which cognitive neuroscience, by using photographic portraits of actors mimicking emotions in fMRI studies, has produced valid stimuli that help to make visible a cerebral difference between adolescents and adults, as well as between girls and boys, in the management of emotional information. In effect, the adolescent emotional brain is constructed along two embedded hierarchies: if the age difference is the founding hierarchy, within that, sex at times act as a driving factor and at times as a moderating one. Las investigaciones en neurociencias que utilizan sets de fotografías de expresión facial a fin de verificar, con la ayuda de técnicas de imaginología, las reacciones emocionales de adolescentes contribuyeron a establecer un modelo neurobiológico del adolescente. Ese modelo que postula que la configuración cerebral particular a ese período de vida somete a las personas jóvenes a un déficit de control emocional, tiende a imponerse en el ámbito de las ciencias del adolescente, particularmente en relación con el aspecto de tomas de riesgo. Este artículo propone investigar el proceso por el cual las neurociencias cognoscitivas elaboraron a partir de retratos fotográficos de actores imitando emociones, estímulos válidos que permitirán de hacer visible por intermedio de IRMs una diferencia del cerebro, discriminando de una parte los adolescentes de los adultos y de otra parte las chicas de los varones en la gestión de la información emocional. En consecuencia, el cerebro emocional adolescente se construye según dos jerarquías encastradas, si la diferencia de edad es la figura de jerarquía fundamental, la del sexo constituye un elemento a veces moderador dentro de la jerarquía fundamental.

Background: Both minor and major head traumas constitute an important proportion of childhood emergency admissions. In this study, the findings of cranial computed tomography (CCT) scans performed as a result of the parental pressure were evaluated. Methods: The frequency and findings of CCT scans performed as a result of parental pressure were examined in a separate subgroup. Results: A total of 227 patients were included in the study; 158 (69.9%) patients had undergone CCT scans; a pathological finding was detected in 24 (10.6%) of these patients and undergone a consultation by the neurosurgeon (most common finding was isolated linear fracture; n = 12; 50%). The patients undergoing CCT scans were divided in two subgroups: the PECARN group [n = 123 (77.8%)] and the Parental pressure group [n = 33 (22.2%)]. Conclusion: One third of the parents of children who presented to the emergency department with head trauma and had no indication for CCT according to PECARN rules insisted on CCT imaging, and none of these cases showed ciTBI, surgical operation, or mortality. None of the patients in the parental pressure group had a history of surgical intervention or mortality within one month after discharge. (c) 2020 Elsevier Inc. All rights reserved. WOS:000659352600064 2-s2.0-85085300528 PubMed: 32471780

INTRODUCTION/AIM: Correct staging of patients with prostate cancer is important for treatment planning and prognosis. Although bone scintigraphy with (99m)Tc-phosphonates (BS) is generally advised for staging by guidelines in high risk prostate cancer, this imaging technique is hampered by a high rate of inconclusive results and moderate accuracy. Potentially better imaging techniques for detection of bone metastases such as (18)F-sodiumfluoride PET/CT (NaF PET/CT) are therefore being evaluated. In this observational cohort study we evaluate the performance and clinical impact of both BS and NaF PET/CT in primary staging of patients with prostate cancer.METHODS: The first of two cohorts consisted of patients who received a BS while the second included patients who received a NaF PET/CT for primary staging of prostate cancer. For both cohorts the number of positive, negative and equivocal findings, calculated diagnostic performance of the imaging modality in terms of sensitivity and specificity, as well as the impact on clinical management were studied. The ranges of the diagnostic performance were calculated both assuming that equivocal findings were positive and assuming that they were negative for bone metastases. For the NaF PET/CT cohort the number of patients with signs of lymph node metastases on low dose CT were also recorded, including the impact of these findings on clinical management.RESULTS: One-hundred-and-four patients underwent NaF PET/CT, whereas 122 patients underwent BS. Sensitivities of 97-100 and 84-95% and specificities of 98-100 and 72-100% were found on a patient basis for detection of bone metastases with NaF PET/CT and BS, respectively. Equivocal findings warranted further diagnostic procedures in 2% of the patients in the NaF cohort and in 16% in the BS cohort. In addition NaF PET/CT demonstrated lymph node metastases in 50% of the included patients, of which 25% showed evidence of lymph node metastases only.CONCLUSION: Our data indicate better diagnostic performance of NaF PET/CT compared to BS for detection of bone metastases in primary staging of prostate cancer patients. Less equivocal findings are encountered with NaF PET/CT. Moreover, NaF PET/CT has additional value over BS since lymph node metastases are encountered frequently.

Statistical analysis of real in-game situations plays an increasing role in talent identification and player recruitment across team sports. Recently, visual exploration frequency (VEF) in football has been discussed as being one of the important performance-determining parameters. However, until now, VEF has been studied almost exclusively in laboratory settings. Moreover, the VEF of individuals has not been correlated with performance parameters in a statistically significant number of top-level players. Thus, the objective of the present study was to examine the relationship between VEF and individual performance parameters in elite football midfielders. Thirty-five midfielders participating in the Euro 2016 championship were analyzed using game video. Their VEF was categorized into scans, transition scans, and total scans. Linear regression analysis was used to correlate the three different VEF parameters with the passing percentage and the turnover rate for individual players. The linear regression showed significant positive correlations between scan rate (p = 0.033, R 2 = 3.0%) and total scan rate (p = 0.015, R 2 = 4.0%) and passing percentage but not between transition scan rate and passing percentage (p = 0.074). There was a significant negative correlation between transition scan rate and turnover rate (p = 0.023, R 2 = 3.5%) but not between total scan rate (p = 0.857) or scan rate (p = 0.817) and turnover rate. In conclusion, the present study shows that players with a higher VEF may complete more passes and cause fewer turnovers. VEF explains up to 4% of variance in pass completion and turnover rate and thus should be considered as one of the factors that can help to evaluate players and identify talents as well as to tailor training interventions to the needs of midfielders up to the highest level of professional football.

Objective To determine patient, institution, and machine characteristics that contribute to variation in radiation doses used for computed tomography (CT). Design Prospective cohort study. Setting Data were assembled and analyzed from the University of California San Francisco CT International Dose Registry. Participants Standardized data from over 2.0 million CT examinations of adults who underwent CT between November 2015 and August 2017 from 151 institutions, across seven countries (Switzerland, Netherlands, Germany, United Kingdom, United States, Israel, and Japan). Main outcome measures Mean effective doses and proportions of high dose examinations for abdomen, chest, combined chest and abdomen, and head CT were determined by patient characteristics (sex, age, and size), type of institution (trauma center, care provision 24 hours per day and seven days per week, academic, private), institutional practice volume, machine factors (manufacturer, model), country, and how scanners were used, before and after adjustment for patient characteristics, using hierarchical linear and logistic regression. High dose examinations were defined as CT scans with doses above the 75th percentile defined during a baseline period. Results The mean effective dose and proportion of high dose examinations varied substantially across institutions. The doses varied modestly (10-30%) by type of institution and machine characteristics after adjusting for patient characteristics. By contrast, even after adjusting for patient characteristics, wide variations in radiation doses across countries persisted, with a fourfold range in mean effective dose for abdomen CT examinations (7.0-25.7 mSv) and a 17-fold range in proportion of high dose examinations (4-69%). Similar variation across countries was observed for chest (mean effective dose 1.7-6.4 mSv, proportion of high dose examinations 1-26%) and combined chest and abdomen CT (10.0-37.9 mSv, 2-78%). Doses for head CT varied less (1.4-1.9 mSv, 8-27%). In multivariable models, the dose variation across countries was primarily attributable to institutional decisions regarding technical parameters (that is, how the scanners were used). Conclusions CT protocols and radiation doses vary greatly across countries and are primarily attributable to local choices regarding technical parameters, rather than patient, institution, or machine characteristics. These findings suggest that the optimization of doses to a consistent standard should be possible. Study registration Clinicaltrials.gov NCT03000751 .

Background: Bronchoscopic lung volume reduction using one-way endobronchial valves (EBVs) has been proven to be effective in patients with severe emphysema. However, the selection of patients without collateral ventilation prior to treatment is critical for procedural success. Collateral ventilation can be assessed directly with the Chartis system or indirectly using computed tomography (CT) fissure analysis. Objectives: We retrospectively evaluated the diagnostic value of a combination of the quantitative CT interlobar fissure completeness score (FCS) and Chartis in predicting responders to EBV therapy. Methods: CT data from four prospective studies were pooled and analyzed using semiautomated software to quantify the completeness of interlobar fissures. These FCSs were compared to a reference standard of achieving ≥350 ml of target lobe volume reduction after EBV treatment. Using a receiver operating characteristic curve, optimal thresholds predictive of complete fissures (responders) and incomplete fissures (non-responders) were determined. A subgroup of patients with partially complete fissures was identified, where software had lower accuracy. The complementary value of Chartis was investigated in this group. Results: A fissure was defined as complete (FCS >95%), incomplete (FCS Conclusion: Combining diagnostic tools could reduce the burden on patients and the healthcare system while providing clinicians with a better means for patient selection for EBV therapy.