Differentiation of COVID-19 Pneumonitis and ICI Induced Pneumonitis

mmune checkpoint inhibitors (ICI) have become the standard of care treatment for several tumor types. ICI-induced pneumonitis is a serious complication seen with treatment with these agents. Cancer has been reported to be one of the risk factors for severe coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), that has engulfed the world in the last couple of months. In patients with cancer treated with ICI who present at the emergency department with respiratory symptoms during the COVID-19 pandemic, correct diagnosis can be challenging. Symptoms and radiological features of ICI pneumonitis can be overlapping with those of COVID-19 related pneumonia. For the latter, dexamethasone and remdesivir have shown encouraging results, while vaccines are currently being evaluated in phase III trials. The mainstay of treatment in ICI pneumonitis is immunosuppressive therapy, as this is a potentially fatal adverse event. It has been speculated that immunosuppression may be associated with increased risk of progression to severe COVID-19, especially during the early stage of infection with SARS-CoV-2. Therefore, distinction between these two entities is warranted. We summarize the clinical, radiological features as well as additional investigations of both entities, and suggest a diagnostic algorithm for distinctio

Толерантный подход к теме греко-турецких взаимоотношений в новейшей греческой прозе

Целью данной статьи стало рассмотрение нового видения дихотомии «грек-турок» в романах греческих писателей второй половины ХХ века

Risk of diabetes after para-aortic radiation for testicular cancer

Background: While the risk of diabetes is increased following radiation exposure to the pancreas among childhood cancer survivors, its association among testicular cancer (TC) survivors has not been investigated. Methods: Diabetes risk was studied in 2998 1-year TC survivors treated before 50 years of age with orchidectomy with/without radiotherapy between 1976 and 2007. Diabetes incidence was compared with general population rates. Treatment-specific risk of diabetes was assessed using a case–cohort design. Results: With a median follow-up of 13.4 years, 161 TC survivors were diagnosed with diabetes. Diabetes risk was not increased compared to general population rates (standardised incidence ratios (SIR): 0.9; 95% confidence interval (95% CI): 0.7–1.1). Adjusted for age, para-aortic radiotherapy was associated with a 1.66-fold (95% CI: 1.05–2.62) increased diabetes risk compared to no radiotherapy. The excess hazard increased with 0.31 with every 10 Gy increase in the prescribed radiation dose (95% CI: 0.11–0.51, P = 0.003, adjusted for age and BMI); restricted to irradiated patients the excess hazard increased with 0.33 (95% CI: −0.14 to 0.81, P = 0.169) with every 10 Gy increase in radiation dose. Conclusion: Compared to surgery only, para-aortic irradiation is associated with increased diabetes risk among TC survivors

Exploring imaging features of molecular subtypes of large cell neuroendocrine carcinoma (LCNEC)

Objectives: Radiological characteristics and radiomics signatures can aid in differentiation between small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC). We investigated whether molecular subtypes of large cell neuroendocrine carcinoma (LCNEC), i.e. SCLC-like (with pRb loss) vs. NSCLC-like (with pRb expression), can be distinguished by imaging based on (1) imaging interpretation, (2) semantic features, and/or (3) a radiomics signature, designed to differentiate between SCLC and NSCLC. Materials and Methods: Pulmonary oncologists and chest radiologists assessed chest CT-scans of 44 LCNEC patients for ‘small cell-like’ or ‘non-small cell-like’ appearance. The radiologists also scored semantic features of 50 LCNEC scans. Finally, a radiomics signature was trained on a dataset containing 48 SCLC and 76 NSCLC scans and validated on an external set of 58 SCLC and 40 NSCLC scans. This signature was applied on scans of 28 SCLC-like and 8 NSCLC-like LCNEC patients. Results: Pulmonary oncologists and radiologists were unable to differentiate between molecular subtypes of LCNEC and no significant differences in semantic features were found. The area under the receiver operating characteristics curve of the radiomics signature in the validation set (SCLC vs. NSCLC) was 0.84 (95% confidence interval (CI) 0.77-0.92) and 0.58 (95% CI 0.29-0.86) in the LCNEC dataset (SCLC-like vs. NSCLC-like). Conclusion: LCNEC appears to have radiological characteristics of both SCLC and NSCLC, irrespective of pRb loss, compatible with the SCLC-like subtype. Imaging interpretation, semantic features and our radiomics signature designed to differentiate between SCLC and NSCLC were unable to separate molecular LCNEC subtypes, which underscores that LCNEC is a unique disease

Automated assessment of COVID-19 reporting and data system and chest CT severity scores in patients suspected of having COVID-19 using artificial intelligence

Background: The coronavirus disease 2019 (COVID-19) pandemic has spread across the globe with alarming speed, morbidity, and mortality. Immediate triage of patients with chest infections suspected to be caused by COVID-19 using chest CT may be of assistance when results from definitive viral testing are delayed.Purpose: To develop and validate an artificial intelligence (AI) system to score the likelihood and extent of pulmonary COVID-19 on chest CT scans using the COVID-19 Reporting and Data System (CO-RADS) and CT severity scoring systems.Materials and Methods: The CO-RADS AI system consists of three deep-learning algorithms that automatically segment the five pulmonary lobes, assign a CO-RADS score for the suspicion of COVID-19, and assign a CT severity score for the degree of parenchymal involvement per lobe. This study retrospectively included patients who underwent a nonenhanced chest CT examination because of clinical suspicion of COVID-19 at two medical centers. The system was trained, validated, and tested with data from one of the centers. Data from the second center served as an external test set. Diagnostic performance and agreement with scores assigned by eight independent observers were measured using receiver operating characteristic analysis, linearly weighted kappa values, and classification accuracy.Results: A total of 105 patients (mean age, 62 years +/- 16 [standard deviation]; 61 men) and 262 patients (mean age, 64 years +/- 16; 154 men) were evaluated in the internal and external test sets, respectively. The system discriminated between patients with COVID-19 and those without COVID-19, with areas under the receiver operating characteristic curve of 0.95 (95% CI: 0.91, 0.98) and 0.88 (95% CI: 0.84, 0.93), for the internal and external test sets, respectively. Agreement with the eight human observers was moderate to substantial, with mean linearly weighted k values of 0.60 +/- 0.01 for CO-RADS scores and 0.54 +/- 0.01 for CT severity scores.Conclusion: With high diagnostic performance, the CO-RADS AI system correctly identified patients with COVID-19 using chest CT scans and assigned standardized CO-RADS and CT severity scores that demonstrated good agreement with findings from eight independent observers and generalized well to external data. (C) RSNA, 2020Cardiovascular Aspects of Radiolog

Low dose computed tomography of the chest : Applications and limitations

In areas with a high intrinsic contrast such as the chest, radiation dose can be reduced for specific indications. Low dose chest CT is feasible and cannot only be applied for lung cancer screening, but also in daily routine and for early detection of lung destruction. We showed in a small sample of patients from the outpatient department of pulmonology that ultralow-dose CT is feasible and can provide more information than CXR in two directions, while radiation dose is similar. The main disadvantage of radiation dose reduction is the accompanying increase in image noise. The detection of abnormalities with a high contrast to the surrounding normal tissue is not limited by the amount of image noise on the CT scans performed with the current minimum radiation dose. However, when the structure of interest shows a low contrast to the surrounding normal tissue, image noise can hamper the detection and especially the automated size measurement of the abnormality. We demonstrated that an increase in image noise results in overestimation of the emphysema score compared to standard dose CT, but also that the application of a dedicated noise reduction filter to the reconstructed data before the automated quantification of emphysema can prevent this overestimations. This thesis is partly based on the Dutch Belgian Lung Cancer Screening project (NELSON), a randomized multi-center trial studying current and former smokers in order to detect lung cancer in an early, treatable stage. The detection of growth is the main feature to distinguish benign non-calcified nodules from potentially benign ones, but interscan and to a lesser extent interobserver variability can limit the detection of growth. We showed that the performance of the algorithm to segment the nodule completely was the most important factor contributing to the variability. Since chronic obstructive pulmonary disease (COPD) and lung cancer share smoking as main risk factor, lung cancer screening trials provide a good opportunity to study the early stages and natural progression of COPD. Emphysema can cause COPD and can easily be detected and automated be quantified on CT by highlighting voxels with an abnormally low X-ray attenuation. We provided the limits of agreement for three common attenuation thresholds for emphysema scores obtained in a lung cancer screening setting. Moreover, we studied the prevalence of emphysema and airflow impairment in participants of the NELSON-project. Many participants showed destructed parenchyma, but a preserved lung function. However, the gas exchange is often already impaired in these subjects, but gas exchange is not one of the hallmarks of COPD (yet). The diffusion of DNO is shown to be a marker of vascular changes, which can precede macroscopic lung tissue destruction. We showed that DNO can be impaired before CT can detect emphysema. Furthermore, we showed that the distribution pattern of emphysema has an impact on the extent of airflow impairment. Current and former smokers with an apical predominance of emphysema showed more severe airflow limitation than subjects with an equal emphysema score, but a basal predominance of lung destruction

Dual-Energy Computed Tomography Compared to Lung Perfusion Scintigraphy to Assess Pulmonary Perfusion in Patients Screened for Endoscopic Lung Volume Reduction

BACKGROUND: Endoscopic lung volume reduction (ELVR) using one-way endobronchial valves is a technique to reduce hyperinflation in patients with severe emphysema by inducing collapse of a severely destroyed pulmonary lobe. Patient selection is mainly based on evaluation of emphysema severity on high-resolution computed tomography and evaluation of lung perfusion with perfusion scintigraphy. Dual-energy contrast-enhanced CT scans may be useful for perfusion assessment in emphysema but has not been compared against perfusion scintigraphy. AIMS: The aim of the study was to compare perfusion distribution assessed with dual-energy contrast-enhanced computed tomography and perfusion scintigraphy. MATERIAL AND METHODS: Forty consecutive patients with severe emphysema, who were screened for ELVR, were included. Perfusion was assessed with 99mTc perfusion scintigraphy and using the iodine map calculated from the dual-energy contrast-enhanced CT scans. Perfusion distribution was calculated as usually for the upper, middle, and lower thirds of both lungs with the planar technique and the iodine overlay. RESULTS: Perfusion distribution between the right and left lung showed good correlation (r = 0.8). The limits of agreement of the mean absolute difference in percentage perfusion per region of interest were 0.75–5.6%. The upper lobes showed more severe perfusion reduction than the lower lobes. Mean difference in measured pulmonary perfusion ranged from −2.8% to 2.3%. Lower limit of agreement ranged from −8.9% to 4.6% and upper limit was 3.3–10.0%. CONCLUSION: Quantification of perfusion distribution using planar 99mTc perfusion scintigraphy and iodine overlays calculated from dual-energy contrast-enhanced CTs correlates well with acceptable variability

Symptomatic mediastinal mass in a 32-year-old male

Most bronchogenic cysts are found incidentally and clinicians should be aware of an atypical case presentation. Total surgical resection is the treatment of choice of a bronchogenic cyst, especially in symptomatic patients. https://bit.ly/3uQrFX