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Objective: To assess the sensitivity of detection and accuracy of volumetry by manual and semi-automated quantification of artificial pulmonary nodules in an anthropomorphic thoracic phantom on low-dose CT.Methods: Fifteen artificial spherical nodules (diameter 3, 5, 8, 10 and 12 mm; CT densities -800, -630 and +100 HU) were randomly placed inside an anthropomorphic thoracic phantom. The phantom was examined on 16- and 64-row multidetector CT with a low-dose protocol. Two independent blinded observers screened for pulmonary nodules. Nodule diameter was measured manually, and volume calculated. For solid nodules (+100 HU), diameter and volume were also evaluated by semi-automated software. Differences in observed volumes between the manual and semi-automated method were evaluated by a t-test.Results: Sensitivity was 100 % for all nodules of >5 mm and larger, 60-80 % for solid and 0-20 % for non-solid 3-mm nodules. No false-positive nodules but high inter-observer reliability and inter-technique correlation were found. Volume was underestimated manually by 24.1 ± 14.0 % for nodules of any density, and 26.4 ± 15.5 % for solid nodules, compared with 7.6 ± 8.5 % (P < 0.01) semi-automatically.Conclusion: In an anthropomorphic phantom study, the sensitivity of detection is 100 % for nodules of >5 mm in diameter. Semi-automated volumetry yielded more accurate nodule volumes than manual measurements. [ABSTRACT FROM AUTHOR]

Objectives: A systematic review and meta-analysis to assess sensitivity and specificity of coronary CT angiography (CCTA) for significant stenosis at different degrees of coronary calcification.Methods: A literature search was performed including studies describing test characteristics of CCTA for significant stenosis, performed with at least 16-MDCT and according to calcium score (CS). Invasive coronary angiography was the reference standard. Pooled sensitivity and specificity of CCTA by CS categories and CT equipment were calculated.Results: Of 14,121 articles, 51 studies reported on the impact of calcium scoring on diagnostic performance of CCTA and could be included in the systematic review. Twenty-seven of these studies (5,203 participants) were suitable for meta-analysis. On a patient-basis, sensitivity of CCTA for significant stenosis was 95.8, 95.6, 97.6 and 99.0% for CS 0-100, 101-400, 401-1,000 and >1,000 respectively. Specificity was 91.2, 88.2, 50.6 and 84.0% respectively. Specificity of CCTA was significantly lower for CS 401-1,000 due to lack of patients without significant stenosis. Sensitivity and specificity of 16-MDCT were significantly lower compared to more modern CT systems.Conclusions: Even in cases of severe coronary calcification, sensitivity and specificity of CCTA for significant stenosis are high. With 64-MDCT and newer CT systems, a CS cut-off for performing CCTA no longer seems indicated.Key Points: Decisions about performing coronary CT angiography (CCTA) sometimes depend on calcium scoring. CCTA is highly sensitive for coronary stenosis. With 16-MDCT, however, heavy calcification reduces specificity for significant stenosis. For 64-MDCT (and above), CCTA has high specificity, even with severe coronary calcification. [ABSTRACT FROM AUTHOR]

Objective: To evaluate performance of computer-aided detection (CAD) beyond double reading for pulmonary nodules on low-dose computed tomography (CT) by nodule volume.Methods: A total of 400 low-dose chest CT examinations were randomly selected from the NELSON lung cancer screening trial. CTs were evaluated by two independent readers and processed by CAD. A total of 1,667 findings marked by readers and/or CAD were evaluated by a consensus panel of expert chest radiologists. Performance was evaluated by calculating sensitivity of pulmonary nodule detection and number of false positives, by nodule characteristics and volume.Results: According to the screening protocol, 90.9 % of the findings could be excluded from further evaluation, 49.2 % being small nodules (less than 50 mm(3)). Excluding small nodules reduced false-positive detections by CAD from 3.7 to 1.9 per examination. Of 151 findings that needed further evaluation, 33 (21.9 %) were detected by CAD only, one of them being diagnosed as lung cancer the following year. The sensitivity of nodule detection was 78.1 % for double reading and 96.7 % for CAD. A total of 69.7 % of nodules undetected by readers were attached nodules of which 78.3 % were vessel-attached.Conclusions: CAD is valuable in lung cancer screening to improve sensitivity of pulmonary nodule detection beyond double reading, at a low false-positive rate when excluding small nodules.Key Points: • Computer-aided detection (CAD) has known advantages for computed tomography (CT). • Combined CAD/nodule size cut-off parameters assist CT lung cancer screening. • This combination improves the sensitivity of pulmonary nodule detection by CT. • It increases the positive predictive value for cancer detection. [ABSTRACT FROM AUTHOR]

Objectives: To determine the correlation between CT measurements of emphysema or peripheral airways and airflow obstruction in chronic obstructive pulmonary disease (COPD).Methods: PubMed, Embase and Web of Knowledge were searched from 1976 to 2011. Two reviewers independently screened 1,763 citations to identify articles that correlated CT measurements to airflow obstruction parameters of the pulmonary function test in COPD patients, rated study quality and extracted information. Three CT measurements were accessed: lung attenuation area percentage < -950 Hounsfield units, mean lung density and airway wall area percentage. Two airflow obstruction parameters were accessed: forced expiratory volume in the first second as percentage from predicted (FEV(1) %pred) and FEV(1) divided by the forced volume vital capacity.Results: Seventy-nine articles (9,559 participants) were included in the systematic review, demonstrating different methodologies, measurements and CT airflow obstruction correlations. There were 15 high-quality articles (2,095 participants) in the meta-analysis. The absolute pooled correlation coefficients ranged from 0.48 (95 % CI, 0.40 to 0.54) to 0.65 (0.58 to 0.71) for inspiratory CT and 0.64 (0.53 to 0.72) to 0.73 (0.63 to 0.80) for expiratory CT.Conclusions: CT measurements of emphysema or peripheral airways are significantly related to airflow obstruction in COPD patients. CT provides a morphological method to investigate airway obstruction in COPD.Key Points: • Computed tomography is widely performed in patients with chronic obstructive pulmonary disease (COPD) • CT provides quantitative morphological methods to investigate airflow obstruction in COPD • CT measurements correlate significantly with the degree of airflow obstruction in COPD • Expiratory CT measurements correlate more strongly with airflow obstruction than inspiratory CT • Low-dose CT decreases the radiation dose for diagnosis and quantitative emphysema evaluation. [ABSTRACT FROM AUTHOR]

Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multidetector CT is discussed. [ABSTRACT FROM AUTHOR]

Introduction: Lung hyperinflation, a key contributor to dyspnea in chronic obstructive pulmonary disease (COPD), can be quantified via chest computed tomography (CT). Establishing reference equations for lobar volumes and total lung volume (TLV) can aid in evaluating lobar hyperinflation, especially for targeted lung volume reduction therapies., Methods: The Imaging in Lifelines study (ImaLife) comprises 11,729 participants aged 45 and above with analyzed inspiratory low-dose thoracic CT scans. Lung and lobar volumes were measured using an automatic AI-based segmentation algorithm (LungSeg). For the main analysis, participants were excluded if they had self-reported COPD/asthma, lung disease on CT, airflow obstruction on lung function testing, were currently smoking, aged over 80 years, or had height outside the 99% confidence interval. Reference equations for TLV and lobar volumes were determined using linear regression considering age and height, stratified by sex. For the subanalysis, participants who were currently smoking or experiencing airflow obstruction were compared to the group of the main analysis., Results: The study included 7306 lung-healthy participants, 97.5% Caucasian, 43.6% men, with mean age of 60.3 ± 9.5 years. Lung and lobar volumes generally increased with age and height. Men consistently had higher volumes than women when adjusted for height. R 2 values ranged from 7.8 to 19.9%. In smokers and those with airway obstruction, volumes were larger than in lung-healthy groups, with the largest increases measured in the upper lobes., Conclusion: The established reference equations for CT-derived TLV and lobar volumes provide a standardized interpretation for individuals aged 45 to 80 of Northern European descent., Key Points: Question Lobar lung volumes can be derived from inspiratory CT scans, but healthy-lung reference values are lacking. Findings Lung and lobar volumes generally increased with age and height. Reference equations for lung/lobar volumes were derived from a sizeable lung-healthy population. Clinical relevance This study provides reference equations for inspiratory CT-derived lung and lobar volumes in a lung-healthy population, potentially useful for assessing candidates for lung volume reduction therapies, for lobe removal in lung cancer patients, and in case of restrictive pulmonary diseases., (© 2024. The Author(s).)

Objective: To investigate the effect of uncertainty estimation on the performance of a Deep Learning (DL) algorithm for estimating malignancy risk of pulmonary nodules., Methods and Materials: In this retrospective study, we integrated an uncertainty estimation method into a previously developed DL algorithm for nodule malignancy risk estimation. Uncertainty thresholds were developed using CT data from the Danish Lung Cancer Screening Trial (DLCST), containing 883 nodules (65 malignant) collected between 2004 and 2010. We used thresholds on the 90th and 95th percentiles of the uncertainty score distribution to categorize nodules into certain and uncertain groups. External validation was performed on clinical CT data from a tertiary academic center containing 374 nodules (207 malignant) collected between 2004 and 2012. DL performance was measured using area under the ROC curve (AUC) for the full set of nodules, for the certain cases and for the uncertain cases. Additionally, nodule characteristics were compared to identify trends for inducing uncertainty., Results: The DL algorithm performed significantly worse in the uncertain group compared to the certain group of DLCST (AUC 0.62 (95% CI: 0.49, 0.76) vs 0.93 (95% CI: 0.88, 0.97); p < .001) and the clinical dataset (AUC 0.62 (95% CI: 0.50, 0.73) vs 0.90 (95% CI: 0.86, 0.94); p < .001). The uncertain group included larger benign nodules as well as more part-solid and non-solid nodules than the certain group., Conclusion: The integrated uncertainty estimation showed excellent performance for identifying uncertain cases in which the DL-based nodule malignancy risk estimation algorithm had significantly worse performance., Clinical Relevance Statement: Deep Learning algorithms often lack the ability to gauge and communicate uncertainty. For safe clinical implementation, uncertainty estimation is of pivotal importance to identify cases where the deep learning algorithm harbors doubt in its prediction., Key Points: • Deep learning (DL) algorithms often lack uncertainty estimation, which potentially reduce the risk of errors and improve safety during clinical adoption of the DL algorithm. • Uncertainty estimation identifies pulmonary nodules in which the discriminative performance of the DL algorithm is significantly worse. • Uncertainty estimation can further enhance the benefits of the DL algorithm and improve its safety and trustworthiness., (© 2024. The Author(s).)

Stable chest pain is a common symptom with multiple potential causes. Non-invasive imaging has an important role in diagnosis and guiding management through the assessment of coronary stenoses, atherosclerotic plaque, myocardial ischaemia or infarction, and cardiac function. Computed tomography (CT) provides the anatomical evaluation of coronary artery disease (CAD) with the assessment of stenosis, plaque type and plaque burden, with additional functional information available from CT fractional flow reserve (FFR) or CT myocardial perfusion imaging. Stress magnetic resonance imaging, nuclear stress myocardial perfusion imaging, and stress echocardiography can assess myocardial ischaemia and other cardiac functional parameters. Coronary CT angiography can be used as a first-line test for many patients with stable chest pain, particularly those with low to intermediate pre-test probability. Functional testing may be considered for patients with known CAD, where the clinical significance is uncertain based on anatomical testing, or in patients with high pre-test probability. This practice recommendations document can be used to guide the selection of non-invasive imaging for patients with stable chest pain and provides brief recommendations on how to perform and report these diagnostic tests. KEY POINTS: The selection of non-invasive imaging tests for patients with stable chest pain should be based on symptoms, pre-test probability, and previous history. Coronary CT angiography can be used as a first-line test for many patients with stable chest pain, particularly those with low to intermediate pre-test probability. Functional testing can be considered for patients with known CAD, where the clinical significance of CAD is uncertain based on anatomical testing, or in patients with high pre-test probability. KEY RECOMMENDATIONS: Non-invasive imaging is an important part of the assessment of patients with stable chest pain. The selection of non-invasive imaging test should be based on symptoms, pre-test probability, and previous history. (Level of evidence: High). Coronary CT angiography can be used as a first line test for many patients with stable chest pain, particularly those with low to intermediate pre-test probability. CT provides information on stenoses, plaque type, plaque volume, and if required functional information with CT fractional flow reserve or CT perfusion. (Level of evidence: High). Functional testing can be considered for patients with known CAD, where the clinical significance of CAD is uncertain based on anatomical testing, or in patients with high pre-test probability. Stress MRI, SPECT, PET, and echocardiography can provide information on myocardial ischemia, along with cardiac functional and other information. (Level of evidence: Medium)., (© 2024. The Author(s), under exclusive licence to European Society of Radiology.)

Rationale: To provide an overview of the current status of cardiac multimodality imaging practices in Europe and radiologist involvement using data from the European Society of Cardiovascular Radiology (ESCR) MRCT-registry., Materials and Methods: Numbers on cardiac CT and MRI examinations were extracted from the MRCT-registry of the ESCR, entered between January 2011 and October 2023 (n = 432,265). Data collection included the total/annual numbers of examinations, indications, complications, and reporting habits., Results: Thirty-two countries contributed to the MRCT-registry, including 29 European countries. Between 2011 and 2022, there was a 4.5-fold increase in annually submitted CT examinations, from 3368 to 15,267, and a 3.8-fold increase in MRI examinations, from 3445 to 13,183. The main indications for cardiac CT were suspected coronary artery disease (CAD) (59%) and transcatheter aortic valve replacement planning (21%). The number of patients with intermediate pretest probability who underwent CT for suspected CAD showed an increase from 61% in 2012 to 82% in 2022. The main MRI indications were suspected myocarditis (26%), CAD (21%), and suspected cardiomyopathy (19%). Adverse event rates were very low for CT (0.3%) and MRI (0.7%) examinations. Reporting of CT and MRI examinations was performed mainly by radiologists (respectively 76% and 71%) and, to a lesser degree, in consensus with non-radiologists (19% and 27%, respectively). The remaining examinations (4.9% CT and 1.7% MRI) were reported by non-radiological specialties or in separate readings of radiologists and non-radiologists., Conclusions: Real-life data on cardiac imaging in Europe using the largest available MRCT-registry demonstrate a considerable increase in examinations over the past years, the vast majority of which are read by radiologists. These findings indicate that radiologists contribute to meeting the increasing demands of competent and effective care in cardiac imaging to a relevant extent., Clinical Relevance Statement: The number of cardiac CT and MRI examinations has risen over the past years, and radiologists read the vast majority of these studies as recorded in the MRCT-registry., Key Points: • The number of cardiac imaging examinations is constantly increasing. • Radiologists play a central role in providing cardiac CT and MR imaging services to a large volume of patients. • Cardiac CT and MR imaging examinations performed and read by radiologists show a good safety profile., (© 2024. The Author(s).)

Objectives: Lung cancer screening (LCS), using low-dose computed tomography (LDCT), can be more efficient by simultaneously screening for chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD), the Big-3 diseases. This study aimed to determine the willingness to participate in (combinations of) Big-3 screening in four European countries and the relative importance of amendable participation barriers., Methods: An online cross-sectional survey aimed at (former) smokers aged 50-75 years elicited the willingness of individuals to participate in Big-3 screening and used analytical hierarchy processing (AHP) to determine the importance of participation barriers., Results: Respondents were from France (n = 391), Germany (n = 338), Italy (n = 399), and the Netherlands (n = 342), and consisted of 51.2% men. The willingness to participate in screening was marginally influenced by the diseases screened for (maximum difference of 3.1%, for Big-3 screening (73.4%) vs. lung cancer and COPD screening (70.3%)) and by country (maximum difference of 3.7%, between France (68.5%) and the Netherlands (72.3%)). The largest effect on willingness to participate was personal perceived risk of lung cancer. The most important barriers were the missed cases during screening (weight 0.19) and frequency of screening (weight 0.14), while diseases screened for (weight 0.11) ranked low., Conclusions: The difference in willingness to participate in LCS showed marginal increase with inclusion of more diseases and limited variation between countries. A marginal increase in participation might result in a marginal additional benefit of Big-3 screening. The amendable participation barriers are similar to previous studies, and the new criterion, diseases screened for, is relatively unimportant., Clinical Relevance Statement: Adding diseases to combination screening modestly improves participation, driven by personal perceived risk. These findings guide program design and campaigns for lung cancer and Big-3 screening. Benefits of Big-3 screening lie in long-term health and economic impact, not participation increase., Key Points: • It is unknown whether or how combination screening might affect participation. • The addition of chronic obstructive pulmonary disease and cardiovascular disease to lung cancer screening resulted in a marginal increase in willingness to participate. • The primary determinant influencing individuals' engagement in such programs is their personal perceived risk of the disease., (© 2023. The Author(s).)

Background and Objective: Bronchiectasis is a frequent incidental finding on chest computed tomography (CT), but its relevance in lung cancer screening is not fully understood. We investigated the association between bronchiectasis and respiratory symptoms, pulmonary function, and emphysema in lung cancer screening participants with and without chronic obstructive pulmonary disease (COPD)., Methods: We included 3260 (ex-)smokers from the Dutch-Belgian lung cancer screening trial (NELSON). Bronchiectasis was scored by chest radiologists. The relationship with pulmonary function (FEV1%predicted, FEV1/FVC), respiratory complaints (cough, dyspnea, wheezing, mucus hypersecretion), and CT-quantified emphysema (15th percentile) was examined with independent t-tests and multivariate regression., Results: Bronchiectasis was present in 5.4% (n = 175/3260). There was no difference in prevalence between subjects with and without COPD (68/1121 [5.9%] vs. 109/2139 [5.1%]; p = .368). COPD subjects with bronchiectasis had a lower FEV1%predicted (76.2% vs. 85.0%; p < .001), lower FEV1/FVC (0.58 vs. 0.62; p < .001), and more emphysema (- 938 HU vs. - 930 HU; p = .001) than COPD subjects without bronchiectasis. In COPD subjects, bronchiectasis was independently associated with a lower FEV1%predicted (B =  - 7.7; CI [- 12.3, - 3.3]), lower FEV1/FVC (B =  - 2.5; CI [- 4.3, - 0.8]), more cough (OR 2.4; CI [1.3, 4.3]), more mucus hypersecretion (OR 1.8; CI [1.0, 3.1]) and more dyspnea (OR 2.3; CI [1.3, 3.9]). In those without COPD (n = 2139), bronchiectasis was associated with more cough, mucus hypersecretion, and wheezing, but not with deteriorating lung function., Conclusion: Bronchiectasis was present in 5.4% of our lung cancer screening participants and was associated with more respiratory symptoms and, in those with COPD, with lower lung function and more emphysema., Clinical Relevance Statement: In a lung cancer screening population, bronchiectasis has a prevalence of 5.4% with a mainly mild severity. This finding is of little clinical relevance unless mild COPD is also present. In those subjects, bronchiectasis was associated with a lower lung function, more respiratory symptoms, and more emphysema., Key Points: • Bronchiectasis was found in 5.4% of lung cancer screening participants, consisting of (ex-)smokers with and without mild COPD. • In those with mild COPD, bronchiectasis was associated with a lower lung function, more respiratory symptoms, and more emphysema. • Incidental findings of mild bronchiectasis are not very relevant in a lung cancer screening population, unless COPD is also present., (© 2023. The Author(s), under exclusive licence to European Society of Radiology.)

Background: The aim of our current systematic dynamic phantom study was first, to optimize reconstruction parameters of coronary CTA (CCTA) acquired on photon counting CT (PCCT) for coronary artery calcium (CAC) scoring, and second, to assess the feasibility of calculating CAC scores from CCTA, in comparison to reference calcium scoring CT (CSCT) scans., Methods: In this phantom study, an artificial coronary artery was translated at velocities corresponding to 0, < 60, and 60-75 beats per minute (bpm) within an anthropomorphic phantom. The density of calcifications was 100 (very low), 200 (low), 400 (medium), and 800 (high) mgHA/cm 3 , respectively. CCTA was reconstructed with the following parameters: virtual non-iodine (VNI), with and without iterative reconstruction (QIR level 2, QIR off, respectively); kernels Qr36 and Qr44f; slice thickness/increment 3.0/1.5 mm and 0.4/0.2 mm. The agreement in risk group classification between CAC CCTA and CAC CSCT scoring was measured using Cohen weighted linear κ with 95% CI., Results: For CCTA reconstructed with 0.4 mm slice thickness, calcium detectability was perfect (100%). At < 60 bpm, CAC CCTA of low, and medium density calcification was underestimated by 53%, and 15%, respectively. However, CAC CCTA was not significantly different from CAC CSCT of very low, and high-density calcifications. The best risk agreement was achieved when CCTA was reconstructed with QIR off, Qr44f, and 0.4 mm slice thickness (κ = 0.762, 95% CI 0.671-0.853)., Conclusion: In this dynamic phantom study, the detection of calcifications with different densities was excellent with CCTA on PCCT using thin-slice VNI reconstruction. Agatston scores were underestimated compared to CSCT but agreement in risk classification was substantial., Clinical Relevance Statement: Photon counting CT may enable the implementation of coronary artery calcium scoring from coronary CTA in daily clinical practice., Key Points: Photon-counting CTA allows for excellent detectability of low-density calcifications at all heart rates. Coronary artery calcium scoring from coronary CTA acquired on photon counting CT is feasible, although improvement is needed. Adoption of the standard acquisition and reconstruction protocol for calcium scoring is needed for improved quantification of coronary artery calcium to fully employ the potential of photon counting CT., (© 2024. The Author(s).)

Objectives: Multiple lung cancer screening studies reported the performance of Lung CT Screening Reporting and Data System (Lung-RADS), but none systematically evaluated its performance across different populations. This systematic review and meta-analysis aimed to evaluate the performance of Lung-RADS (versions 1.0 and 1.1) for detecting lung cancer in different populations., Methods: We performed literature searches in PubMed, Web of Science, Cochrane Library, and Embase databases on October 21, 2022, for studies that evaluated the accuracy of Lung-RADS in lung cancer screening. A bivariate random-effects model was used to estimate pooled sensitivity and specificity, and heterogeneity was explored in stratified and meta-regression analyses., Results: A total of 31 studies with 104,224 participants were included. For version 1.0 (27 studies, 95,413 individuals), pooled sensitivity was 0.96 (95% confidence interval [CI]: 0.90-0.99) and pooled specificity was 0.90 (95% CI: 0.87-0.92). Studies in high-risk populations showed higher sensitivity (0.98 [95% CI: 0.92-0.99] vs. 0.84 [95% CI: 0.50-0.96]) and lower specificity (0.87 [95% CI: 0.85-0.88] vs. 0.95 (95% CI: 0.92-0.97]) than studies in general populations. Non-Asian studies tended toward higher sensitivity (0.97 [95% CI: 0.91-0.99] vs. 0.91 [95% CI: 0.67-0.98]) and lower specificity (0.88 [95% CI: 0.85-0.90] vs. 0.93 [95% CI: 0.88-0.96]) than Asian studies. For version 1.1 (4 studies, 8811 individuals), pooled sensitivity was 0.91 (95% CI: 0.83-0.96) and specificity was 0.81 (95% CI: 0.67-0.90)., Conclusion: Among studies using Lung-RADS version 1.0, considerable heterogeneity in sensitivity and specificity was noted, explained by population type (high risk vs. general), population area (Asia vs. non-Asia), and cancer prevalence., Clinical Relevance Statement: Meta-regression of lung cancer screening studies using Lung-RADS version 1.0 showed considerable heterogeneity in sensitivity and specificity, explained by the different target populations, including high-risk versus general populations, Asian versus non-Asian populations, and populations with different lung cancer prevalence., Key Points: • High-risk population studies showed higher sensitivity and lower specificity compared with studies performed in general populations by using Lung-RADS version 1.0. • In non-Asian studies, the diagnostic performance of Lung-RADS version 1.0 tended to be better than in Asian studies. • There are limited studies on the performance of Lung-RADS version 1.1, and evidence is lacking for Asian populations., (© 2023. The Author(s).)

Objectives: Computed tomography (CT)-based bronchial parameters correlate with disease status. Segmentation and measurement of the bronchial lumen and walls usually require significant manpower. We evaluate the reproducibility of a deep learning and optimal-surface graph-cut method to automatically segment the airway lumen and wall, and calculate bronchial parameters., Methods: A deep-learning airway segmentation model was newly trained on 24 Imaging in Lifelines (ImaLife) low-dose chest CT scans. This model was combined with an optimal-surface graph-cut for airway wall segmentation. These tools were used to calculate bronchial parameters in CT scans of 188 ImaLife participants with two scans an average of 3 months apart. Bronchial parameters were compared for reproducibility assessment, assuming no change between scans., Results: Of 376 CT scans, 374 (99%) were successfully measured. Segmented airway trees contained a mean of 10 generations and 250 branches. The coefficient of determination (R 2 ) for the luminal area (LA) ranged from 0.93 at the trachea to 0.68 at the 6 th generation, decreasing to 0.51 at the 8 th generation. Corresponding values for Wall Area Percentage (WAP) were 0.86, 0.67, and 0.42, respectively. Bland-Altman analysis of LA and WAP per generation demonstrated mean differences close to 0; limits of agreement (LoA) were narrow for WAP and Pi10 (± 3.7% of mean) and wider for LA (± 16.4-22.8% for 2-6 th generations). From the 7 th generation onwards, there was a sharp decrease in reproducibility and a widening LoA., Conclusion: The outlined approach for automatic bronchial parameter measurement on low-dose chest CT scans is a reliable way to assess the airway tree down to the 6 th generation., Statement on Clinical Relevance: This reliable and fully automatic pipeline for bronchial parameter measurement on low-dose CT scans has potential applications in screening for early disease and clinical tasks such as virtual bronchoscopy or surgical planning, while also enabling the exploration of bronchial parameters in large datasets., Key Points: • Deep learning combined with optimal-surface graph-cut provides accurate airway lumen and wall segmentations on low-dose CT scans. • Analysis of repeat scans showed that the automated tools had moderate-to-good reproducibility of bronchial measurements down to the 6 th generation airway. • Automated measurement of bronchial parameters enables the assessment of large datasets with less man-hours., (© 2023. The Author(s).)

Cardiac computed tomography (CT) and cardiac magnetic resonance imaging (MRI) are routine radiological examinations for diagnosis and prognosis of cardiac disease. The expected growth in cardiac radiology in the coming years will exceed the current scanner capacity and trained workforce. The European Society of Cardiovascular Radiology (ESCR) focuses on supporting and strengthening the role of cardiac cross-sectional imaging in Europe from a multi-modality perspective. Together with the European Society of Radiology (ESR), the ESCR has taken the initiative to describe the current status of, a vision for, and the required activities in cardiac radiology to sustain, increase and optimize the quality and availability of cardiac imaging and experienced radiologists across Europe. KEY POINTS: • Providing adequate availability for performing and interpreting cardiac CT and MRI is essential, especially with expanding indications. • The radiologist has a central role in non-invasive cardiac imaging examinations which encompasses the entire process from selecting the best modality to answer the referring physician's clinical question to long-term image storage. • Optimal radiological education and training, knowledge of the imaging process, regular updating of diagnostic standards, and close collaboration with colleagues from other specialties are essential., (© 2023. The Author(s).)

The European Society of Cardiovascular Radiology (ESCR) is the European specialist society of cardiac and vascular imaging. This society's highest priority is the continuous improvement, development, and standardization of education, training, and best medical practice, based on experience and evidence. The present intra-society consensus is based on the existing scientific evidence and on the individual experience of the members of the ESCR writing group on carotid diseases, the members of the ESCR guidelines committee, and the members of the executive committee of the ESCR. The recommendations published herein reflect the evidence-based society opinion of ESCR. The purpose of this second document is to discuss suggestions for standardized reporting based on the accompanying consensus document part I. KEY POINTS: • CT and MR imaging-based evaluation of carotid artery disease provides essential information for risk stratification and prediction of stroke. • The information in the report must cover vessel morphology, description of stenosis, and plaque imaging features. • A structured approach to reporting ensures that all essential information is delivered in a standardized and consistent way to the referring clinician., (© 2022. The Author(s).)

The European Society of Cardiovascular Radiology (ESCR) is the European specialist society of cardiac and vascular imaging. This society's highest priority is the continuous improvement, development, and standardization of education, training, and best medical practice, based on experience and evidence. The present intra-society consensus is based on the existing scientific evidence and on the individual experience of the members of the ESCR writing group on carotid diseases, the members of the ESCR guidelines committee, and the members of the executive committee of the ESCR. The recommendations published herein reflect the evidence-based society opinion of ESCR. We have produced a twin-papers consensus, indicated through the documents as respectively "Part I" and "Part II." The first document (Part I) begins with a discussion of features, role, indications, and evidence for CT and MR imaging-based diagnosis of carotid artery disease for risk stratification and prediction of stroke (Section I). It then provides an extensive overview and insight into imaging-derived biomarkers and their potential use in risk stratification (Section II). Finally, detailed recommendations about optimized imaging technique and imaging strategies are summarized (Section III). The second part of this consensus paper (Part II) is focused on structured reporting of carotid imaging studies with CT/MR. KEY POINTS: • CT and MR imaging-based evaluation of carotid artery disease provides essential information for risk stratification and prediction of stroke. • Imaging-derived biomarkers and their potential use in risk stratification are evolving; their correct interpretation and use in clinical practice must be well-understood. • A correct imaging strategy and scan protocol will produce the best possible results for disease evaluation., (© 2022. The Author(s).)

Objectives: Coronary motion artifacts affect the diagnostic accuracy of coronary CT angiography (CCTA), especially in the mid right coronary artery (mRCA). The purpose is to correct CCTA motion artifacts of the mRCA using a GAN (generative adversarial network)., Methods: We included 313 patients with CCTA scans, who had paired motion-affected and motion-free reference images at different R-R interval phases in the same cardiac cycle and included another 53 CCTA cases with invasive coronary angiography (ICA) comparison. Pix2pix, an image-to-image conversion GAN, was trained by the motion-affected and motion-free reference pairs to generate motion-free images from the motion-affected images. Peak signal-to-noise ratio (PSNR), structural similarity (SSIM), Dice similarity coefficient (DSC), and Hausdorff distance (HD) were calculated to evaluate the image quality of GAN-generated images., Results: At the image level, the median of PSNR, SSIM, DSC, and HD of GAN-generated images were 26.1 (interquartile: 24.4-27.5), 0.860 (0.830-0.882), 0.783 (0.714-0.825), and 4.47 (3.00-4.47), respectively, significantly better than the motion-affected images (p < 0.001). At the patient level, the image quality results were similar. GAN-generated images improved the motion artifact alleviation score (4 vs. 1, p < 0.001) and overall image quality score (4 vs. 1, p < 0.001) than those of the motion-affected images. In patients with ICA comparison, GAN-generated images achieved accuracy of 81%, 85%, and 70% in identifying no, < 50%, and ≥ 50% stenosis, respectively, higher than 66%, 72%, and 68% for the motion-affected images., Conclusion: Generative adversarial network-generated CCTA images greatly improved the image quality and diagnostic accuracy compared to motion-affected images., Key Points: • A generative adversarial network greatly reduced motion artifacts in coronary CT angiography and improved image quality. • GAN-generated images improved diagnosis accuracy of identifying no, < 50%, and ≥ 50% stenosis., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: This study aimed to evaluate the association between visual emphysema and the presence of lung nodules, and Lung-RADS category with low-dose CT (LDCT)., Methods: Baseline LDCT scans of 1162 participants from a lung cancer screening study (Nelcin-B3) performed in a Chinese general population were included. The presence, subtypes, and severity of emphysema (at least trace) were visually assessed by one radiologist. The presence, size, and classification of non-calcified lung nodules (≥ 30 mm 3 ) and Lung-RADS category were independently assessed by another two radiologists. Multivariable logistic regression and stratified analyses were performed to estimate the association between emphysema and lung nodules, Lung-RADS category, after adjusting for age, sex, BMI, smoking status, pack-years, and passive smoking., Results: Emphysema and lung nodules were observed in 674 (58.0%) and 424 (36.5%) participants, respectively. Participants with emphysema had a 71% increased risk of having lung nodules (adjusted odds ratios, aOR: 1.71, 95% CI: 1.26-2.31) and 70% increased risk of positive Lung-RADS category (aOR: 1.70, 95% CI: 1.09-2.66) than those without emphysema. Participants with paraseptal emphysema (n = 47, 4.0%) were at a higher risk for lung nodules than those with centrilobular emphysema (CLE) (aOR: 2.43, 95% CI: 1.32-4.50 and aOR: 1.60, 95% CI: 1.23-2.09, respectively). Only CLE was associated with positive Lung-RADS category (p = 0.02). CLE severity was related to a higher risk of lung nodules (ranges aOR: 1.44-2.61, overall p < 0.01)., Conclusion: In a Chinese general population, visual emphysema based on LDCT is independently related to the presence of lung nodules (≥ 30 mm 3 ) and specifically CLE subtype is related to positive Lung-RADS category. The risk of lung nodules increases with CLE severity., Key Points: • Participants with emphysema had an increased risk of having lung nodules, especially smokers. • Participants with PSE were at a higher risk for lung nodules than those with CLE, but nodules in participants with CLE had a higher risk of positive Lung-RADS category. • The risk of lung nodules increases with CLE severity., (© 2022. The Author(s).)

Objective: Research on computed tomography (CT) bronchial parameter measurements shows that there are conflicting results on the values for bronchial parameters in the never-smoking, smoking, asthma, and chronic obstructive pulmonary disease (COPD) populations. This review assesses the current CT methods for obtaining bronchial wall parameters and their comparison between populations., Methods: A systematic review of MEDLINE and Embase was conducted following PRISMA guidelines (last search date 25th October 2021). Methodology data was collected and summarised. Values of percentage wall area (WA%), wall thickness (WT), summary airway measure (Pi10), and luminal area (Ai) were pooled and compared between populations., Results: A total of 169 articles were included for methodologic review; 66 of these were included for meta-analysis. Most measurements were obtained from multiplanar reconstructions of segmented airways (93 of 169 articles), using various tools and algorithms; third generation airways in the upper and lower lobes were most frequently studied. COPD (12,746) and smoking (15,092) populations were largest across studies and mostly consisted of men (median 64.4%, IQR 61.5 - 66.1%). There were significant differences between populations; the largest WA% was found in COPD (mean SD 62.93 ± 7.41%, n = 6,045), and the asthma population had the largest Pi10 (4.03 ± 0.27 mm, n = 442). Ai normalised to body surface area (Ai/BSA) (12.46 ± 4 mm 2 , n = 134) was largest in the never-smoking population., Conclusions: Studies on CT-derived bronchial parameter measurements are heterogenous in methodology and population, resulting in challenges to compare outcomes between studies. Significant differences between populations exist for several parameters, most notably in the wall area percentage; however, there is a large overlap in their ranges., Key Points: • Diverse methodology in measuring airways contributes to overlap in ranges of bronchial parameters among the never-smoking, smoking, COPD, and asthma populations. • The combined number of never-smoking participants in studies is low, limiting insight into this population and the impact of participant characteristics on bronchial parameters. • Wall area percent of the right upper lobe apical segment is the most studied (87 articles) and differentiates all except smoking vs asthma populations., (© 2022. The Author(s).)

Objectives: To compare the use of coronary computed tomography angiography (CCTA) between academic and non-academic sites across Europe over the last decade., Methods: We analyzed a large multicenter registry (ESCR MR/CT Registry) of stable symptomatic patients who received CCTA 01/2010-01/2020 at 47 (22%) academic and 165 (78%) non-academic sites across 19 European countries. We compared image quality, radiation dose, contrast-media-related adverse events, patient characteristics, CCTA findings, and downstream testing between academic and non-academic sites., Results: Among 64,317 included patients (41% female; 60 ± 13 years), academic sites accounted for most cases in 2010-2014 (52%), while non-academic sites dominated in 2015-2020 (71%). Despite less contemporary technology, non-academic sites maintained low radiation doses (4.76 [2.46-6.85] mSv) with a 30% decline of high-dose scans ( > 7 mSv) over time. Academic and non-academic sites both reported diagnostic image quality in 98% of cases and low rate of scan-related adverse events (0.4%). Academic and non-academic sites examined similar patient populations (41% females both; age: 61 ± 14 vs. 60 ± 12 years; pretest probability for obstructive CAD: low 21% vs. 23%, intermediate 73% vs. 72%, high 6% both, CAD prevalence on CCTA: 40% vs. 41%). Nevertheless, non-academic sites referred more patients to non-invasive ischemia testing (6.5% vs. 4.2%) and invasive coronary angiography/surgery (8.5% vs. 5.6%)., Conclusions: Non-academic and academic sites provide safe, high-quality CCTA across Europe, essential to successfully implement the recently updated guidelines for the diagnosis and management of chronic coronary syndromes. However, despite examining similar populations with comparable CAD prevalence, non-academic sites tend to refer more patients to downstream testing., Key Points: • Smaller non-academic providers increasingly use CCTA to rule out obstructive coronary artery disease. • Non-academic and academic sites provide comparably safe, high-quality CCTA across Europe. • Compared to academic sites, non-academic sites tend to refer more patients to downstream testing., (© 2022. The Author(s), under exclusive licence to European Society of Radiology.)

Objectives: Estimating the maximum acceptable cost (MAC) per screened individual for low-dose computed tomography (LDCT) lung cancer (LC) screening, and determining the effect of additionally screening for chronic obstructive pulmonary disease (COPD), cardiovascular disease (CVD), or both on the MAC., Methods: A model-based early health technology assessment (HTA) was conducted to estimate whether a new intervention could be cost-effective by calculating the MAC at a willingness-to-pay (WTP) of €20k/quality-adjusted life-year (QALY) and €80k/QALY, for a population of current and former smokers, aged 50-75 years in The Netherlands. The MAC was estimated based on incremental QALYs gained from a stage shift assuming screened individuals are detected in earlier disease stages. Data were obtained from literature and publicly available statistics and validated with experts., Results: The MAC per individual for implementing LC screening at a WTP of €20k/QALY was €113. If COPD, CVD, or both were included in screening, the MAC increased to €230, €895, or €971 respectively. Scenario analyses assessed whether screening-specific disease high-risk populations would improve cost-effectiveness, showing that high-risk CVD populations were more likely to improve economic viability compared to COPD., Conclusions: The economic viability of combined screening is substantially larger than for LC screening alone, primarily due to benefits from CVD screening, and is dependent on the target screening population, which is key to optimise the screening program. The total cost of breast and cervical cancer screening is lower (€420) than the MAC of Big-3, indicating that Big-3 screening may be acceptable from a health economic perspective., Key Points: • Once-off combined low-dose CT screening for lung cancer, COPD, and CVD in individuals aged 50-75 years is potentially cost-effective if screening would cost less than €971 per screened individual. • Multi-disease screening requires detailed insight into the co-occurrence of these diseases to identify the optimal target screening population. • With the same target screening population and WTP, lung cancer-only screening should cost less than €113 per screened individual to be cost-effective., (© 2021. The Author(s).)

Objectives: The interpretability of convolutional neural networks (CNNs) for classifying subsolid nodules (SSNs) is insufficient for clinicians. Our purpose was to develop CNN models to classify SSNs on CT images and to investigate image features associated with the CNN classification., Methods: CT images containing SSNs with a diameter of ≤ 3 cm were retrospectively collected. We trained and validated CNNs by a 5-fold cross-validation method for classifying SSNs into three categories (benign and preinvasive lesions [PL], minimally invasive adenocarcinoma [MIA], and invasive adenocarcinoma [IA]) that were histologically confirmed or followed up for 6.4 years. The mechanism of CNNs on human-recognizable CT image features was investigated and visualized by gradient-weighted class activation map (Grad-CAM), separated activation channels and areas, and DeepDream algorithm., Results: The accuracy was 93% for classifying 586 SSNs from 569 patients into three categories (346 benign and PL, 144 MIA, and 96 IA in 5-fold cross-validation). The Grad-CAM successfully located the entire region of image features that determined the final classification. Activated areas in the benign and PL group were primarily smooth margins (p < 0.001) and ground-glass components (p = 0.033), whereas in the IA group, the activated areas were mainly part-solid (p < 0.001) and solid components (p < 0.001), lobulated shapes (p < 0.001), and air bronchograms (p < 0.001). However, the activated areas for MIA were variable. The DeepDream algorithm showed the image features in a human-recognizable pattern that the CNN learned from a training dataset., Conclusion: This study provides medical evidence to interpret the mechanism of CNNs that helps support the clinical application of artificial intelligence., Key Points: • CNN achieved high accuracy (93%) in classifying subsolid nodules on CT images into three categories: benign and preinvasive lesions, MIA, and IA. • The gradient-weighted class activation map (Grad-CAM) located the entire region of image features that determined the final classification, and the visualization of the separated activated areas was consistent with radiologists' expertise for diagnosing subsolid nodules. • DeepDream showed the image features that CNN learned from a training dataset in a human-recognizable pattern., (© 2021. European Society of Radiology.)

Objectives: To investigate the association of pericoronary adipose tissue mean attenuation (PCAT MA ) with coronary artery disease (CAD) characteristics on coronary computed tomography angiography (CCTA)., Methods: We retrospectively investigated 165 symptomatic patients who underwent third-generation dual-source CCTA at 70kVp: 93 with and 72 without CAD (204 arteries with plaque, 291 without plaque). CCTA was evaluated for presence and characteristics of CAD per artery. PCAT MA was measured proximally and across the most severe stenosis. Patient-level, proximal PCAT MA was defined as the mean of the proximal PCAT MA of the three main coronary arteries. Analyses were performed on patient and vessel level., Results: Mean proximal PCAT MA was -96.2 ± 7.1 HU and -95.6 ± 7.8HU for patients with and without CAD (p = 0.644). In arteries with plaque, proximal and lesion-specific PCAT MA was similar (-96.1 ± 9.6 HU, -95.9 ± 11.2 HU, p = 0.608). Lesion-specific PCAT MA of arteries with plaque (-94.7 HU) differed from proximal PCAT MA of arteries without plaque (-97.2 HU, p = 0.015). Minimal stenosis showed higher lesion-specific PCAT MA (-94.0 HU) than severe stenosis (-98.5 HU, p = 0.030). Lesion-specific PCAT MA of non-calcified, mixed, and calcified plaque was -96.5 HU, -94.6 HU, and -89.9 HU (p = 0.004). Vessel-based total plaque, lipid-rich necrotic core, and calcified plaque burden showed a very weak to moderate correlation with proximal PCAT MA ., Conclusions: Lesion-specific PCAT MA was higher in arteries with plaque than proximal PCAT MA in arteries without plaque. Lesion-specific PCAT MA was higher in non-calcified and mixed plaques compared to calcified plaques, and in minimal stenosis compared to severe; proximal PCAT MA did not show these relationships. This suggests that lesion-specific PCAT MA is related to plaque development and vulnerability., Key Points: • In symptomatic patients undergoing CCTA at 70 kVp, PCAT MA was higher in coronary arteries with plaque than those without plaque. • PCAT MA was higher for non-calcified and mixed plaques compared to calcified plaques, and for minimal stenosis compared to severe stenosis. • In contrast to PCAT MA measurement of the proximal vessels, lesion-specific PCAT MA showed clear relationships with plaque presence and stenosis degree., (© 2021. The Author(s).)

Machine learning offers great opportunities to streamline and improve clinical care from the perspective of cardiac imagers, patients, and the industry and is a very active scientific research field. In light of these advances, the European Society of Cardiovascular Radiology (ESCR), a non-profit medical society dedicated to advancing cardiovascular radiology, has assembled a position statement regarding the use of machine learning (ML) in cardiovascular imaging. The purpose of this statement is to provide guidance on requirements for successful development and implementation of ML applications in cardiovascular imaging. In particular, recommendations on how to adequately design ML studies and how to report and interpret their results are provided. Finally, we identify opportunities and challenges ahead. While the focus of this position statement is ML development in cardiovascular imaging, most considerations are relevant to ML in radiology in general. KEY POINTS: • Development and clinical implementation of machine learning in cardiovascular imaging is a multidisciplinary pursuit. • Based on existing study quality standard frameworks such as SPIRIT and STARD, we propose a list of quality criteria for ML studies in radiology. • The cardiovascular imaging research community should strive for the compilation of multicenter datasets for the development, evaluation, and benchmarking of ML algorithms.

Objectives: To evaluate the performance of a novel convolutional neural network (CNN) for the classification of typical perifissural nodules (PFN)., Methods: Chest CT data from two centers in the UK and The Netherlands (1668 unique nodules, 1260 individuals) were collected. Pulmonary nodules were classified into subtypes, including "typical PFNs" on-site, and were reviewed by a central clinician. The dataset was divided into a training/cross-validation set of 1557 nodules (1103 individuals) and a test set of 196 nodules (158 individuals). For the test set, three radiologically trained readers classified the nodules into three nodule categories: typical PFN, atypical PFN, and non-PFN. The consensus of the three readers was used as reference to evaluate the performance of the PFN-CNN. Typical PFNs were considered as positive results, and atypical PFNs and non-PFNs were grouped as negative results. PFN-CNN performance was evaluated using the ROC curve, confusion matrix, and Cohen's kappa., Results: Internal validation yielded a mean AUC of 91.9% (95% CI 90.6-92.9) with 78.7% sensitivity and 90.4% specificity. For the test set, the reader consensus rated 45/196 (23%) of nodules as typical PFN. The classifier-reader agreement (k = 0.62-0.75) was similar to the inter-reader agreement (k = 0.64-0.79). Area under the ROC curve was 95.8% (95% CI 93.3-98.4), with a sensitivity of 95.6% (95% CI 84.9-99.5), and specificity of 88.1% (95% CI 81.8-92.8)., Conclusion: The PFN-CNN showed excellent performance in classifying typical PFNs. Its agreement with radiologically trained readers is within the range of inter-reader agreement. Thus, the CNN-based system has potential in clinical and screening settings to rule out perifissural nodules and increase reader efficiency., Key Points: • Agreement between the PFN-CNN and radiologically trained readers is within the range of inter-reader agreement. • The CNN model for the classification of typical PFNs achieved an AUC of 95.8% (95% CI 93.3-98.4) with 95.6% (95% CI 84.9-99.5) sensitivity and 88.1% (95% CI 81.8-92.8) specificity compared to the consensus of three readers.

Objectives: To determine normal pericoronary adipose tissue mean attenuation (PCAT MA ) values for left the anterior descending (LAD), left circumflex (LCX), and right coronary artery (RCA) in patients without plaques on coronary CT angiography (cCTA), taking into account tube voltage influence., Methods: This retrospective study included 192 patients (76 (39.6%) men; median age 49 years (range, 19-79)) who underwent cCTA with third-generation dual-source CT for the suspicion of CAD between 2015 and 2017. We selected patients without plaque on cCTA. PCAT MA was measured semi-automatically on cCTA images in the proximal segment of the three main coronary arteries with 10 mm length. Paired t-testing was used to compare PCAT MA between combinations of two coronary arteries within each patient, and one-way ANOVA testing was used to compare PCAT MA in different kV groups., Results: The overall mean ± standard deviation (SD) PCAT MA was - 90.3 ± 11.1 HU. PCAT MA in men was higher than that in women: - 88.5 ± 10.5 HU versus - 91.5 ± 11.3 HU (p = 0.001). PCAT MA of LAD, LCX, and RCA was - 92.4 ± 11.6 HU, - 88.4 ± 9.9 HU, and - 90.2 ± 11.4 HU, respectively. Pairwise comparison of the arteries showed significant difference in PCAT MA : LAD and LCX (p < 0.001), LAD and RCA (p = 0.009), LCX and RCA (p = 0.033). PCAT MA of the 70 kV, 80 kV, 90 kV, 100 kV, and 120 kV groups was - 95.6 ± 9.6 HU, - 90.2 ± 11.5 HU, - 87.3 ± 9.9 HU, - 82.7 ± 6.2 HU, and - 79.3 ± 6.8 HU, respectively (p < 0.001)., Conclusions: In patients without plaque on cCTA, PCAT MA varied by tube voltage, with minor differences in PCAT MA between coronary arteries (LAD, LCX, RCA). PCAT MA values need to be interpreted taking into account tube voltage setting., Key Points: • In patients without plaque on cCTA, PCAT MA differs slightly by coronary artery (LAD, LCX, RCA). • Tube voltage of cCTA affects PCAT MA measurement, with mean PCAT MA increasing linearly with increasing kV. • For longitudinal cCTA analysis of PCAT MA , the use of equal kV setting is strongly recommended.

Transcatheter aortic valve replacement (TAVR) is a minimally invasive alternative to conventional aortic valve replacement in symptomatic patients with severe aortic stenosis and contraindications to surgery. The procedure has shown to improve patient's quality of life and prolong short- and mid-term survival in high-risk individuals, becoming a widely accepted therapeutic option which has been integrated into current clinical guidelines for the management of valvular heart disease. Nevertheless, not every patient at high-risk for surgery is a good candidate for TAVR. Besides clinical selection, which is usually established by the Heart Team, certain technical and anatomic criteria must be met as, unlike in surgical valve replacement, annular sizing is not performed under direct surgical evaluation but on the basis of non-invasive imaging findings. Present consensus document was outlined by a working group of researchers from the European Society of Cardiovascular Radiology (ESCR) and aims to provide guidance on the utilisation of CT and MR imaging prior to TAVR. Particular relevance is given to the technical requirements and standardisation of the scanning protocols which have to be tailored to the remarkable variability of the scanners currently utilised in clinical practice; recommendations regarding all required pre-procedural measurements and medical reporting standardisation have been also outlined, in order to ensure quality and consistency of reported data and terminology. KEY POINTS: • To provide a reference document for CT and MR acquisition techniques, taking into account the significant technological variation of available scanners. • To review all relevant measurements that are required and define a step-by-step guided approach for the measurements of different structures implicated in the procedure. • To propose a CT/MR reporting template to assist in consistent communication between various sites and specialists involved in the procedural planning.

Objectives: To assess the incidence of acute adverse events (AAEs) in gadolinium-enhanced cardiac magnetic resonance (CMR) imaging., Methods: Gadolinium-based contrast agent (GBCA)-enhanced CMR data from the multinational, multicenter European Society of Cardiovascular Radiology MRCT Registry was included. AAE severity was classified according to the American College of Radiology Manual on Contrast Media (mild, moderate, severe). Multivariable generalized linear mixed effect models were used to assess the likelihood of AAEs in various GBCA, adjusting for pharmacological stressor, main indications (i.e., suspected or known coronary artery disease or myocarditis), age, sex, and submitting center as a random effect., Results: In the study population of 72,839 GBCA-enhanced CMRs, a total of 260 AAEs were reported (0.36%), with a minority of severe AAEs (n = 24, 0.033%). Allergic-like AAEs were less likely than physiologic AAEs (29% versus 71%). Patients without pharmacological stress imaging had a lower AAE rate (0.22%) compared to stress imaging (0.75%), with the highest AAE rates for regadenoson (2.95%). AAE rates also varied by GBCA subtype (overall p < 0.001). There was significant interaction between GBCA and pharmacological stressor (interaction p = 0.025), with AAE rates ranging between 0 and 10% for certain GBCA/stressor combinations. There was further marginal evidence that higher GBCA volume was associated with higher AAE incidence (OR = 1.02, p = 0.05)., Conclusion: GBCA-enhanced CMR imaging demonstrates low AAE rates comparable to those of other body regions. AAE likelihood correlates with GBCA subtype, pharmacological stressor, and imaging indication. Intravenous fluid administration in patients with cardiac impairment might contribute to these findings., Key Points: • Acute adverse event rates in cardiac magnetic resonance (CMR) imaging with gadolinium-based contrast agents (GBCAs) are low (0.36%), especially for severe adverse events (0.033%). • Mild and moderate adverse events are more frequent during stress CMR imaging. • Physiologic AAEs are more common than allergic AAEs in CMR imaging.

Positron emission tomography (PET) and magnetic resonance imaging (MRI) have both been used for decades in cardiovascular imaging. Since 2010, hybrid PET/MRI using sequential and integrated scanner platforms has been available, with hybrid cardiac PET/MR imaging protocols increasingly incorporated into clinical workflows. Given the range of complementary information provided by each method, the use of hybrid PET/MRI may be justified and beneficial in particular clinical settings for the evaluation of different disease entities. In the present joint position statement, we critically review the role and value of integrated PET/MRI in cardiovascular imaging, provide a technical overview of cardiac PET/MRI and practical advice related to the cardiac PET/MRI workflow, identify cardiovascular applications that can potentially benefit from hybrid PET/MRI, and describe the needs for future development and research. In order to encourage its wide dissemination, this article is freely accessible on the European Radiology and European Journal of Hybrid Imaging web sites., Key Points: • Studies and case-reports indicate that PET/MRI is a feasible and robust technology. • Promising fields of application include a variety of cardiac conditions. • Larger studies are required to demonstrate its incremental and cost-effective value. • The translation of novel radiopharmaceuticals and MR-sequences will provide exciting new opportunities.

Objectives: To study the ratio of ablation zone volume to applied energy in computed tomography (CT)-guided radiofrequency ablation (RFA) and microwave ablation (MWA) in patients with hepatocellular carcinoma (HCC) in a cirrhotic liver and in patients with colorectal liver metastasis (CRLM)., Methods: In total, 90 liver tumors, 45 HCCs in a cirrhotic liver and 45 CRLMs were treated with RFA or with one of two MWA devices (MWA&#95;A and MWA&#95;B), resulting in 15 procedures for each tumor type, per device. Device settings were recorded and the applied energy was calculated. Ablation volumes were segmented on the contrast-enhanced CT scans obtained 1 week after the procedure. The ratio of ablation zone volume in milliliters to applied energy in kilojoules was determined for each procedure and compared between HCC (R HCC ) and CRLM (R CRLM ), stratified according to ablation device., Results: With RFA, R HCC and R CRLM were 0.22 mL/kJ (0.14-0.45 mL/kJ) and 0.15 mL/kJ (0.14-0.22 mL/kJ; p = 0.110), respectively. With MWA&#95;A, R HCC was 0.81 (0.61-1.07 mL/kJ) and R CRLM was 0.43 (0.35-0.61 mL/kJ; p = 0.001). With MWA&#95;B, R HCC was 0.67 (0.41-0.85 mL/kJ) and R CRLM was 0.43 (0.35-0.61 mL/kJ; p = 0.040)., Conclusions: With RFA, there was no significant difference in energy deposition ratio between tumor types. With both MWA devices, the ratios were higher for HCCs. Tailoring microwave ablation device protocols to tumor type might prevent incomplete ablations., Key Points: • HCCs and CRLMs respond differently to microwave ablation • For MWA, CRLMs required more energy to achieve a similar ablation volume • Tailoring ablation protocols to tumor type might prevent incomplete ablations.

Objectives: Early synthetic gadolinium enhancement (ESGE) imaging from post-contrast T1 mapping after adenosine stress-perfusion cardiac magnetic resonance (CMR) was compared to conventional late gadolinium enhancement (LGE) imaging for assessing myocardial scar., Methods: Two hundred fourteen consecutive patients suspected of myocardial ischaemia were referred for stress-perfusion CMR. Myocardial infarct volume was quantified on a per-subsegment basis in both synthetic (2-3 min post-gadolinium) and conventional (9 min post-gadolinium) images by two independent observers. Sensitivity, specificity, PPV and NPV were calculated on a per-patient and per-subsegment basis., Results: Both techniques detected 39 gadolinium enhancement areas in 23 patients. The median amount of scar was 2.0 (1.0-3.1) g in ESGE imaging and 2.2 (1.1-3.1) g in LGE imaging (p=0.39). Excellent correlation (r=0.997) and agreement (mean absolute difference: -0.028±0.289 ml) were found between ESGE and LGE images. Sensitivity, specificity, PPV and NPV of ESGE imaging were 96 (78.9-99.9), 99 (97.1-100.0)%, 96 (76.5-99.4) and 99.5 (96.6-99.9) in patient-based and 99 (94.5-100.0), 100 (99.9-100.0)%, 97.0 (91.3-99.0) and 100.0 (99.8-100.0) in subsegment-based analysis., Conclusion: ESGE based on post-contrast T1 mapping after adenosine stress-perfusion CMR imaging shows excellent agreement with conventional LGE imaging for assessing myocardial scar, and can substantially shorten clinical acquisition time., Key Points: • Synthetic gadolinium enhancement images can be used for detection of myocardial scar. • Early synthetic gadolinium enhancement images can substantially shorten clinical acquisition time. • ESGE has high diagnostic accuracy as compared to conventional late gadolinium enhancement. • Quantification of myocardial scar with ESGE closely correlates with conventional LGE. • ESGE after stress perfusion CMR avoids need for additional gadolinium administration.

Objective: To determine the accuracy of iodine quantification with dual energy computed tomography (DECT) in two high-end CT systems with different spectral imaging techniques., Methods: Five tubes with different iodine concentrations (0, 5, 10, 15, 20 mg/ml) were analysed in an anthropomorphic thoracic phantom. Adding two phantom rings simulated increased patient size. For third-generation dual source CT (DSCT), tube voltage combinations of 150Sn and 70, 80, 90, 100 kVp were analysed. For dual layer CT (DLCT), 120 and 140 kVp were used. Scans were repeated three times. Median normalized values and interquartile ranges (IQRs) were calculated for all kVp settings and phantom sizes., Results: Correlation between measured and known iodine concentrations was excellent for both systems (R = 0.999-1.000, p < 0.0001). For DSCT, median measurement errors ranged from -0.5% (IQR -2.0, 2.0%) at 150Sn/70 kVp and -2.3% (IQR -4.0, -0.1%) at 150Sn/80 kVp to -4.0% (IQR -6.0, -2.8%) at 150Sn/90 kVp. For DLCT, median measurement errors ranged from -3.3% (IQR -4.9, -1.5%) at 140 kVp to -4.6% (IQR -6.0, -3.6%) at 120 kVp. Larger phantom sizes increased variability of iodine measurements (p < 0.05)., Conclusion: Iodine concentration can be accurately quantified with state-of-the-art DECT systems from two vendors. The lowest absolute errors were found for DSCT using the 150Sn/70 kVp or 150Sn/80 kVp combinations, which was slightly more accurate than 140 kVp in DLCT., Key Points: • High-end CT scanners allow accurate iodine quantification using different DECT techniques. • Lowest measurement error was found in scans with largest photon energy separation. • Dual-source CT quantified iodine slightly more accurately than dual layer CT.

Objectives: To evaluate the influence of inversion time (TI) on the precision of myocardial late gadolinium enhancement (LGE) quantification using synthetic inversion recovery (IR) imaging in patients with myocardial infarction (MI)., Methods: Fifty-three patients with suspected prior MI underwent 1.5-T cardiac MRI with conventional magnitude (MagIR) and phase-sensitive IR (PSIR) LGE imaging and T1 mapping at 15 min post-contrast. T1-based synthetic MagIR and PSIR images were calculated with a TI ranging from -100 to +150 ms at 5-ms intervals relative to the optimal TI (TI 0 ). LGE was quantified using a five standard deviation (5SD) and full width at half-maximum (FWHM) thresholds. Measurements were compared using one-way analysis of variance., Results: The MagIR sy technique provided precise assessment of LGE area at TIs ≥ TI 0 , while precision was decreased below TI 0 . The LGE area showed significant differences at ≤ -25 ms compared to TI 0 using 5SD (P < 0.001) and at ≤ -65 ms using the FWHM approach (P < 0.001). LGE measurements did not show significant difference over the analysed TI range in the PSIR sy images using either of the quantification methods., Conclusions: T1 map-based PSIR sy images provide precise quantification of MI independent of TI at the investigated time point post-contrast. MagIR sy -based MI quantification is precise at TI 0 and at longer TIs while showing decreased precision at TI values below TI 0 ., Key Points: • Synthetic IR imaging retrospectively generates LGE images at any theoretical TI • Synthetic IR imaging can simulate the effect of TI on LGE quantification • Fifteen minutes post-contrast MagIR sy accurately quantifies infarcts from TI 0 to TI 0   + 150 ms • Fifteen minutes post-contrast PSIR sy provides precise infarct size independent of TI • Synthetic IR imaging has further advantages in reducing operator dependence.

Objectives: To evaluate detectability and quantification of coronary calcifications for CT with a tin filter for spectral shaping., Methods: Phantom inserts with 100 small and 9 large calcifications, and a moving artificial artery with 3 calcifications (speed 0-30 mm/s) were placed in a thorax phantom simulating different patient sizes. The phantom was scanned in high-pitch spiral mode at 100 kVp with tin filter (Sn100 kVp), and at a reference of 120 kVp, with electrocardiographic (ECG) gating. Detectability and quantification of calcifications were analyzed for standard (130 HU) and adapted thresholds., Results: Sn100 kVp yielded lower detectability of calcifications (9 % versus 12 %, p = 0.027) and lower Agatston scores (p < 0.008), irrespective of calcification, patient size and speed. Volume scores of the moving calcifications for Sn100 kVp at speed 10-30 mm/s were lower (p < 0.001), while mass scores were similar (p = 0.131). For Sn100 kVp with adapted threshold of 117 HU, detectability (p = 1.000) and Agatston score (p > 0.206) were similar to 120 kVp. Spectral shaping resulted in median dose reduction of 62.3 % (range 59.0-73.4 %)., Conclusions: Coronary calcium scanning with spectral shaping yields lower detectability of calcifications and lower Agatston scores compared to 120 kVp scanning, for which a HU threshold correction should be developed., Key Points: • Sn100kVp yields lower detectability and lower Agatston scores compared to 120kVp • Adapted HU threshold for Sn100kVp provides Agatston scores comparable to 120kVp • Sn100 kVp considerably reduces dose in calcium scoring versus 120 kVp.

Rationale: We aimed to test the interscan variation of semi-automatic volumetry of subsolid nodules (SSNs), as growth evaluation is important for SSN management., Methods: From a lung cancer screening trial all SSNs that were stable over at least 3 months were included (N = 44). SSNs were quantified on the baseline CT by two observers using semi-automatic volumetry software for effective diameter, volume, and mass. One observer also measured the SSNs on the second CT 3 months later. Interscan variation was evaluated using Bland-Altman plots. Observer agreement was calculated as intraclass correlation coefficient (ICC). Data are presented as mean (± standard deviation) or median and interquartile range (IQR). A Mann-Whitney U test was used for the analysis of the influence of adjustments on the measurements., Results: Semi-automatic measurements were feasible in all 44 SSNs. The interscan limits of agreement ranged from -12.0 % to 9.7 % for diameter, -35.4 % to 28.6 % for volume and -27.6 % to 30.8 % for mass. Agreement between observers was good with intraclass correlation coefficients of 0.978, 0.957, and 0.968 for diameter, volume, and mass, respectively., Conclusion: Our data suggest that when using our software an increase in mass of 30 % can be regarded as significant growth., Key Points: • Recently, recommendations regarding subsolid nodules have stressed the importance of growth quantification. • Volumetric measurement of subsolid nodules is feasible with good interscan agreement. • Increase of mass of 30 % can be regarded as significant growth.

Objective: To evaluate the impact of radiological expertise on screen result decisions in a CT lung cancer screening trial., Methods: In the NELSON lung cancer screening trial, the baseline CT result was based on the largest lung nodule's volume. The protocol allowed radiologists to manually adjust screen results in cases of high suspicion of benign or malignant nodule nature. Participants whose baseline CT result was based on a solid or part-solid nodule were included in this study. Adjustments by radiologists at baseline were evaluated. Histology was the reference for diagnosis or to confirm benignity and stability on subsequent CT examinations., Results: A total of 3,318 participants (2,796 male, median age 58.0 years) were included. In 195 participants (5.9 %) the initial baseline screen result was adjusted by the radiologist. Adjustment was downwards from positive or indeterminate to negative in two and 119 participants, respectively, and from positive to indeterminate in 65 participants. None of these nodules turned out to be malignant. In 9/195 participants (4.6 %) the screen result was adjusted upwards from negative to indeterminate or indeterminate to positive; two nodules were malignant., Conclusion: In one in 20 cases of baseline lung cancer screening, nodules were reclassified by the radiologist, leading to a reduction of false-positive screen results.

Objective: To determine whether semiautomatic volumetric software can differentiate part-solid from nonsolid pulmonary nodules and aid quantification of the solid component., Methods: As per reference standard, 115 nodules were differentiated into nonsolid and part-solid by two radiologists; disagreements were adjudicated by a third radiologist. The diameters of solid components were measured manually. Semiautomatic volumetric measurements were used to identify and quantify a possible solid component, using different Hounsfield unit (HU) thresholds. The measurements were compared with the reference standard and manual measurements., Results: The reference standard detected a solid component in 86 nodules. Diagnosis of a solid component by semiautomatic software depended on the threshold chosen. A threshold of -300 HU resulted in the detection of a solid component in 75 nodules with good sensitivity (90%) and specificity (88%). At a threshold of -130 HU, semiautomatic measurements of the diameter of the solid component (mean 2.4 mm, SD 2.7 mm) were comparable to manual measurements at the mediastinal window setting (mean 2.3 mm, SD 2.5 mm [p = 0.63])., Conclusion: Semiautomatic segmentation of subsolid nodules could diagnose part-solid nodules and quantify the solid component similar to human observers. Performance depends on the attenuation segmentation thresholds. This method may prove useful in managing subsolid nodules., Key Points: • Semiautomatic segmentation can accurately differentiate nonsolid from part-solid pulmonary nodules • Semiautomatic segmentation can quantify the solid component similar to manual measurements • Semiautomatic segmentation may aid management of subsolid nodules following Fleischner Society recommendations • Performance for the segmentation of subsolid nodules depends on the chosen attenuation thresholds.

Objective: The objective of this study was to investigate the association of spirometry and pulmonary CT biomarkers with cardiovascular events., Methods: In this lung cancer screening trial 3,080 male participants without a prior cardiovascular event were analysed. Fatal and non-fatal cardiovascular events were included. Spirometry included forced expiratory volume measured in units of one-second percent predicted (FEV1%predicted) and FEV1 divided by forced vital capacity (FVC; FEV1/FVC). CT examinations were quantified for coronary artery calcium volume, pulmonary emphysema (perc15) and bronchial wall thickness (pi10). Data were analysed via a Cox proportional hazard analysis, net reclassification improvement (NRI) and C-indices., Results: 184 participants experienced a cardiovascular event during a median follow-up of 2.9 years. Age, pack-years and smoking status adjusted hazard ratios were 0.992 (95% confidence interval (CI) 0.985-0.999) for FEV1%predicted, 1.000 (95%CI 0.986-1.015) for FEV1/FVC, 1.014 (95%CI 1.005-1.023) for perc15 per 10 HU, and 1.269 (95%CI 1.024-1.573) for pi10 per 1 mm. The incremental C-index (<0.015) and NRI (<2.8%) were minimal. Coronary artery calcium volume had a hazard ratio of 1.046 (95%CI 1.034-1.058) per 100 mm(3), an increase in C-index of 0.076 and an NRI of 16.9% (P < 0.0001)., Conclusions: Pulmonary CT biomarkers and spirometry measurements were significantly associated with cardiovascular events, but did not contain clinically relevant independent prognostic information for cardiovascular events., Key Points: • Pulmonary CT biomarkers and spirometry are associated with cardiovascular events • These pulmonary measurements do not contain clinically relevant independent prognostic information • Only coronary calcium score improved cardiovascular risk prediction above age and smoking.

Objectives: To analyse computed tomography (CT) findings of interval and post-screen carcinomas in lung cancer screening., Methods: Consecutive interval and post-screen carcinomas from the Dutch-Belgium lung cancer screening trial were included. The prior screening and the diagnostic chest CT were reviewed by two experienced radiologists in consensus with knowledge of the tumour location on the diagnostic CT., Results: Sixty-one participants (53 men) were diagnosed with an interval or post-screen carcinoma. Twenty-two (36%) were in retrospect visible on the prior screening CT. Detection error occurred in 20 cancers and interpretation error in two cancers. Errors involved intrabronchial tumour (n = 5), bulla with wall thickening (n = 5), lymphadenopathy (n = 3), pleural effusion (n = 1) and intraparenchymal solid nodules (n = 8). These were missed because of a broad pleural attachment (n = 4), extensive reticulation surrounding a nodule (n = 1) and extensive scarring (n = 1). No definite explanation other than human error was found in two cases. None of the interval or post-screen carcinomas involved a subsolid nodule., Conclusions: Interval or post-screen carcinomas that were visible in retrospect were mostly due to detection errors of solid nodules, bulla wall thickening or endobronchial lesions. Interval or post-screen carcinomas without explanation other than human errors are rare., Key Points: • 22% of missed carcinomas originally presented as bulla wall thickening on CT. • 22% of missed carcinomas originally presented as endobronchial lesions on CT. • All malignant endobronchial lesions presented as interval carcinomas. • In the NELSON trial subsolid nodules were not a source of missed carcinomas.