The BRAF P.V600E Mutation Status of Melanoma Lung Metastases Cannot Be Discriminated on Computed Tomography by LIDC Criteria nor Radiomics Using Machine Learning.

Patients with BRAF mutated (BRAF-mt) metastatic melanoma benefit significantly from treatment with BRAF inhibitors. Currently, the BRAF status is determined on archival tumor tissue or on fresh tumor tissue from an invasive biopsy. The aim of this study was to evaluate whether radiomics can predict the BRAF status in a non-invasive manner. Patients with melanoma lung metastases, known BRAF status, and a pretreatment computed tomography scan were included. After semi-automatic annotation of the lung lesions (maximum two per patient), 540 radiomics features were extracted. A chest radiologist scored all segmented lung lesions according to the Lung Image Database Consortium (LIDC) criteria. Univariate analysis was performed to assess the predictive value of each feature for BRAF mutation status. A combination of various machine learning methods was used to develop BRAF decision models based on the radiomics features and LIDC criteria. A total of 169 lung lesions from 103 patients (51 BRAF-mt; 52 BRAF wild type) were included. There were no features with a significant discriminative value in the univariate analysis. Models based on radiomics features and LIDC criteria both performed as poorly as guessing. Hence, the BRAF mutation status in melanoma lung metastases cannot be predicted using radiomics features or visually scored LIDC criteria.

Preoperative Chest Computed Tomography Screening for Coronavirus Disease 2019 in Asymptomatic Patients Undergoing Cardiac Surgery.

Due to the outbreak of Severe Acute Respiratory Syndrome coronavirus (SARS-Cov-2), an efficient COVID-19 screening strategy is required for patients undergoing cardiac surgery. The objective of this prospective observational study was to evaluate the role of preoperative computed tomography (CT) screening for COVID-19 in a population of COVID-19 asymptomatic patients scheduled for cardiac surgery. Between the 29th of March and the 26th of May 2020, patients asymptomatic for COVID-19 underwent a CT-scan the day before surgery, with reverse-transcriptase polymerase-chain reaction (RT-PCR) reserved for abnormal scan results. The primary endpoint was the prevalence of abnormal scans, which was evaluated using the CO-RADS score, a COVID-19 specific grading system. In a secondary analysis, the rate of abnormal scans was compared between the screening cohort and matched historical controls who underwent routine preoperative CT-screening prior to the SARS-Cov-2 outbreak. Of the 109 patients that underwent CT-screening, an abnormal scan result was observed in 7.3% (95% confidence interval: 3.2-14.0%). One patient, with a normal screening CT, was tested positive for COVID-19, with the first positive RT-PCR on the ninth day after surgery. A rate of preoperative CT-scan abnormalities of 8% (n = 8) was found in the unexposed historical controls (P > 0.999). In asymptomatic patients undergoing cardiac surgery, preoperative screening for COVID-19 using computed tomography will identify pulmonary abnormalities in a small percentage of patients that do not seem to have COVID-19. Depending on the prevalence of COVID-19, this results in an unfavorable positive predictive value of CT screening. Care should be taken when considering CT as a screening tool prior to cardiac surgery.

Bone suppression increases the visibility of invasive pulmonary aspergillosis in chest radiographs.

OBJECTIVE: Chest radiographs (CXR) are an important diagnostic tool for the detection of invasive pulmonary aspergillosis (IPA) in critically ill patients, but their diagnostic value is limited by a poor sensitivity. By using advanced image processing, the aim of this study was to increase the value of chest radiographs in the diagnostic work up of neutropenic patients who are suspected of IPA. METHODS: The frontal CXRs of 105 suspected cases of IPA were collected from four institutions. Radiographs could contain single or multiple sites of infection. CT was used as reference standard. Five radiologists and two residents participated in an observer study for the detection of IPA on CXRs with and without bone suppressed images (ClearRead BSI 3.2; Riverain Technologies). The evaluation was performed separately for the right and left lung, resulting in 78 diseased cases (or lungs) and 132 normal cases (or lungs). For each image, observers scored the likelihood of focal infectious lesions being present on a continuous scale (0-100). The area under the receiver operating characteristics curve (AUC) served as the performance measure. Sensitivity and specificity were calculated by considering only the lungs with a suspiciousness score of greater than 50 to be positive. RESULTS: The average AUC for only CXRs was 0.815. Performance significantly increased, to 0.853, when evaluation was aided with BSI (p = 0.01). Sensitivity increased from 49% to 66% with BSI, while specificity decreased from 95% to 90%. CONCLUSION: The detection of IPA in CXRs can be improved when their evaluation is aided by bone suppressed images. BSI improved the sensitivity of the CXR examination, outweighing a small loss in specificity.

Burden of atherosclerosis improves the prediction of coronary heart disease but not cerebrovascular events: the Rotterdam Study.

AIMS: Since atherosclerosis is a systemic process, risk prediction would benefit from targeting multiple components of cardiovascular disease simultaneously. To this end, it is useful to examine the predictive value of non-invasive measures of atherosclerosis in various vascular beds for both coronary heart disease (CHD) and cerebrovascular disease. METHODS AND RESULTS: Between September 2003 and February 2006, 2153 asymptomatic participants (69.6±6.6 years) from the Rotterdam Study underwent a multi-detector computed tomography scan. During a median follow-up of 3.5 years, 58 CHD events (myocardial infarction and CHD death) and 52 cerebrovascular events (TIA and stroke) occurred. Participants were classified into low (<5%), intermediate (5-10%), and high (>10%) 5-year risk categories based on a refitted Framingham risk model. The model was extended by coronary, aortic arch, or carotid calcium and reclassification percentages were calculated. For the outcome CHD, the C-statistic improved from 0.693 for the Framingham refitted model to 0.743, 0.740, and 0.749 by addition of coronary, aortic arch, and carotid calcium, respectively. Reclassification was most substantial in the intermediate risk group where addition of coronary calcium reclassified 56% of persons [net reclassification improvement (NRI): 15%; P<0.01)]. Adding aortic arch calcium led to a reclassification of 32% of persons (NRI: 8%; P=0.01) and adding carotid calcium reclassified 51% (NRI: 9%; P=0.02). In contrast, calcification in any of the three vascular beds did not improve cerebrovascular risk prediction. CONCLUSION: Coronary, aortic arch, and carotid artery calcification significantly improved risk prediction of CHD but not of cerebrovascular events.

Carotid, aortic arch and coronary calcification are related to history of stroke: the Rotterdam Study.

OBJECTIVE: Multidetector computed tomography (MDCT), which has been mainly used to study coronary atherosclerosis, also enables non-invasive measurement of carotid and aortic atherosclerosis and might be suitable for screening in the general population. The aim of this study was to investigate the associations of carotid artery, aortic arch and coronary artery calcification as assessed by MDCT, with presence of stroke. METHODS: The study was embedded in the population-based Rotterdam Study and comprises 2521 persons (mean age 69.7±6.8 years, 48% males) that underwent an MDCT scan. History of stroke was reported by 96 persons. We used multivariable logistic regression to investigate the associations of calcification in the carotid arteries, aortic arch, and coronary arteries with presence of stroke. RESULTS: We found strong and graded associations of prevalent stroke with carotid artery (OR quartile 4 versus 1 (95% CI): 5.0 (2.2-11.0)), aortic arch (3.3 (1.5-7.4)) and coronary artery calcification (3.1 (1.3-7.3)), independent of cardiovascular risk factors. Only the association of carotid artery calcification with presence of stroke was independent of calcification in the other two vessel beds. CONCLUSION: In this population-based study, we found a strong and graded association of prevalent stroke with carotid artery, aortic arch and coronary artery calcification, independent of cardiovascular risk factors. After additional adjustment for calcification in the other vessel beds, prevalent stroke was still significantly related to carotid calcification, but no longer to aortic arch or coronary calcification.

Association between calcification in the coronary arteries, aortic arch and carotid arteries: the Rotterdam study.

OBJECTIVE: The present study was performed to examine the prevalence of and associations between calcification in the coronary arteries, aortic arch and carotid arteries, assessed by multislice computed tomography (MSCT), in an elderly population. METHODS AND RESULTS: This study was part of the population-based Rotterdam study. From October 2003 until July 2004, subjects underwent a 16-slice MSCT scan. Calcification was quantified by calculating the Agatston, volume and mass score. Current analyses were performed in 600 subjects (mean age 74 years). The prevalences of calcification in the coronary and carotid arteries were higher in men compared to women. However, aortic arch calcification was more prevalent among women. In men, correlation coefficients based on the Agatston score ranged from 0.40 (between coronary and aortic arch calcification) to 0.54 (between aortic arch and carotid calcification) (p<0.001). Correlation coefficients for women ranged from 0.30 (between coronary and aortic arch calcification) to 0.40 (between coronary and carotid calcification) (p<0.001). CONCLUSIONS: While the prevalences of calcification in the coronary and the carotid arteries were higher in men compared to women, aortic arch calcification was more prevalent among women. Moderate to strong correlations between calcification in different vessel beds were found.