COVID-19 pneumonia imaging follow-up: when and how? A proposition from ESTI and ESR.

This document from the European Society of Thoracic Imaging (ESTI) and the European Society of Radiology (ESR) discusses the role of imaging in the long-term follow-up of COVID-19 patients, to define which patients may benefit from imaging, and what imaging modalities and protocols should be used. Insights into imaging features encountered on computed tomography (CT) scans and potential pitfalls are discussed and possible areas for future review and research are also included. KEY POINTS: • Post-COVID-19 pneumonia changes are mainly consistent with prior organizing pneumonia and are likely to disappear within 12 months of recovery from the acute infection in the majority of patients. • At present, with the longest series of follow-up examinations reported not exceeding 12 months, the development of persistent or progressive fibrosis in at least some individuals cannot yet be excluded. • Residual ground glass opacification may be associated with persisting bronchial dilatation and distortion, and might be termed "fibrotic-like changes" probably consistent with prior organizing pneumonia.

[Value of CT and transthoracic lung ultrasound in patients with systemic sclerosis : Joint statement of the ÖRG/ÖGP/ÖGR/ÖGUM]. / Wertigkeit der CT und des transthorakalen Lungenultraschalls bei PatientInnen mit systemischer Sklerose : Gemeinsame Stellungnahme der ÖRG/ÖGP/ÖGR/ÖGUM.

Lung involvement is the most frequent cause of death in patients with systemic sclerosis (SSc). As lung involvement is frequently asymptomatic, the current recommendation is to carry out thoracic computed tomography (CT) in all patients newly diagnosed with SSc. There is currently disagreement on how patients with SSc for whom no lung involvement was found at the time of diagnosis, should be followed up. Based on a consensus of Austrian rheumatologists, pneumologists and radiologists it is recommended that for asymptomatic patients with a negative CT at the time of initial diagnosis, a transthoracic ultrasound examination should be carried out annually and a lung function examination every 6-12 months. In the presence of a positive lung ultrasound finding a supplementary CT for further clarification is recommended. Based on the data situation, annual CT follow-up controls are recommended for patients with a high risk as defined by appropriate risk factors.

[Artificial intelligence in lung imaging]. / Künstliche Intelligenz in der Bildgebung der Lunge.

CLINICAL/METHODICAL ISSUE: Artificial intelligence (AI) has the potential to improve diagnostic accuracy and management in patients with lung disease through automated detection, quantification, classification, and prediction of disease progression. STANDARD RADIOLOGICAL METHODS: Owing to unspecific symptoms, few well-defined CT disease patterns, and varying prognosis, interstitial lungs disease represents a focus of AI-based research. METHODICAL INNOVATIONS: Supervised and unsupervised machine learning can identify CT disease patterns using features which may allow the analysis of associations with specific diseases and outcomes. PERFORMANCE: Machine learning on the one hand improves computer-aided detection of pulmonary nodules. On the other hand it enables further characterization of pulmonary nodules, which may improve resource effectiveness regarding lung cancer screening programs. ACHIEVEMENTS: There are several challenges regarding AI-based CT data analysis. Besides the need for powerful algorithms, expert annotations and extensive training data sets that reflect physiologic and pathologic variability are required for effective machine learning. Comparability and reproducibility of AI research deserve consideration due to a lack of standardization in this emerging field. PRACTICAL RECOMMENDATIONS: This review article presents the state of the art and the challenges concerning AI in lung imaging with special consideration of interstitial lung disease, and detection and consideration of pulmonary nodules.

[Lung cancer screening]. / Lungenkarzinom-Screening.

CLINICAL/METHODICAL ISSUE: The National Lung Screening Trial (NLST) in 2011 was able to prove for the first time that screening with a low-dose CT can reduce lung carcinoma mortality by 20%. Despite the positive outcome of the NLST, there is-unlike in the USA-currently no systematic lung cancer screening in Europe. This is partly because several significantly smaller screening studies in Europe failed to show any improvement in lung cancer mortality. STANDARD RADIOLOGICAL METHODS: On the other hand, Europe's healthcare systems differ substantially from those in the United States, so that a direct transfer of US experience to Europe is not possible. For this reason, guidelines for lung cancer screening must be developed in the individual European countries to ensure that lung cancer mortality can be reduced by means of a quality-assured and cost-effective lung cancer screening. PRACTICAL RECOMMENDATIONS: The experience and the expected results of the European screening studies can provide valuable help for these purposes.

Machine learning: from radiomics to discovery and routine.

Machine learning is rapidly gaining importance in radiology. It allows for the exploitation of patterns in imaging data and in patient records for a more accurate and precise quantification, diagnosis, and prognosis. Here, we outline the basics of machine learning relevant for radiology, and review the current state of the art, the limitations, and the challenges faced as these techniques become an important building block of precision medicine. Furthermore, we discuss the roles machine learning can play in clinical routine and research and predict how it might change the field of radiology.

[Pulmonary carcinoid tumors]. / Pulmonale Karzinoide.

Pulmonary carcinoids are rare low-grade malignant tumors, which arise from the neuroendocrine system. Approximately 80% of all pulmonary carcinoid tumors are the relatively low-grade typical carcinoids and 20% are the more aggressive atypical carcinoids. Most carcinoids arise from the central airways and only a minority of carcinoids are found in the lung periphery. While most of the peripheral carcinoids are asymptomatic, central carcinoids are symptomatic and present with hemoptysis, wheezing or bronchial obstruction. On computed tomography (CT), carcinoids frequently present as hypervascular pulmonary nodules in close proximity to the bronchial system. Due to the bronchial obstruction, many patients with pulmonary carcinoids present with post-obstructive pneumonia or atelectasis. While fluorodeoxyglucose positron emission tomography CT (FDG-PET/CT) is of limited value in typical carcinoids due to the high rate of false negatives, somatostatin analogs are promising tracers in staging as well as in the planning of peptide receptor radionuclide therapy.

EFSUMB statement on medical student education in ultrasound [short version].

The European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) recommends that ultrasound should be used systematically as an easy accessible and instructive educational tool in the curriculum of modern medical schools. Medical students should acquire theoretical knowledge of the modality and hands-on training should be implemented and adhere to evidence-based principles. In this paper we summarise EFSUMB policy statements on medical student education in ultrasound.

[Lung cancer screening - risk stratification : Who should undergo screening?]. / Bronchialkarzinomscreening - Risikostratifizierung : Wer soll gescreent werden?

Lung cancer is one of the leading causes of deaths in Europa and the USA. In approximately 75 % of lung cancer patients, bronchogenic carcinoma is detected at an advanced tumor stage; therefore, therapeutic options which aim at curing the disease in these patients are limited and treatment is mostly palliative. A relatively good prognosis is reserved for the minority of patients where the tumor is detected at an early stage and treatment is potentially curative. For this reason, early diagnosis of lung cancer could save lives. Retrospective analyses of the US national lung screening trial (NLST) showed that especially high-risk populations (e. g. higher age, positive smoking history, overweight and a positive family history for lung cancer) benefit most from lung cancer screening. Thus, the effectiveness of computed tomography (CT) screening can be improved by focusing on high-risk populations. This review article summarizes the risk stratification models of the large European and American screening studies and discusses possible future biomarkers for risk stratification.

[Extrathoracic manifestations of tuberculosis]. / Extrathorakale Manifestationen der Tuberkulose.

CLINICAL/METHODICAL ISSUE: Besides the lungs, tuberculosis (TB) can affect any organ system. In most cases, extrathoracic TB occurs in immunosuppressed patients as part of a severe illness via hematogenous spread. Extrathoracic involvement most commonly involves abdominal organs, especially the urogenital tract and less commonly the central nervous system (CNS) and the musculoskeletal system. Most frequently, computed tomography (CT) is used for detecting extrathoracic TB manifestations, except for CNS and musculoskeletal manifestations, where contrast-enhanced magnetic resonance imaging (MRI) is the gold standard. Extrathoracic manifestations of TB may be indistinguishable from inflammatory or malignant causes. Due to unspecific symptoms the diagnosis is often delayed. This article summarizes and discusses the various radiological manifestations of extrathoracic manifestation of TB. STANDARD RADIOLOGICAL METHODS: Radiological modalities for screening extrathoracic TB are CT and MRI. Conventional X­radiographs do not play a role in the diagnosis of extrathoracic TB. PRACTICAL RECOMMENDATIONS: The possibility of extrathoracic TB should be considered particularly in immunosuppressed patients, such as the homeless, alcoholics or drug addicts or in patients with an immigrant background from the endemic areas of TB. The most likely site of extrathoracic TB is the abdomen; however, infections of the CNS or musculoskeletal systems and multisystem infections can also occur. In patients with suspected extrathoracic TB, radiological modalities for screening are CT, especially for abdominal infections and lymphadenopathy and MRI with contrast media for the musculoskeletal system and the CNS.

[Thoracic manifestation of tuberculosis]. / Thorakale Manifestation der Tuberkulose.

CLINICAL ISSUE: Tuberculosis (TB) is a granulomatous disease caused by Mycobacterium tuberculosis and transmission is via an airborne route by droplet infection. In the majority of cases patients have thoracic TB, which most frequently presents with hilar lymphadenopathy and pulmonary manifestation. Due to the rise in incidence of TB in central Europe to be expected over the coming years, it is essential to be acquainted with the radiological manifestations of pulmonary TB, particularly to be able to discriminate active from inactive TB. Due to the use of molecular techniques entailing DNA fingerprinting, the traditional classification of TB in primary and postprimary TB is being challenged. These genetic studies have revealed that variations in the clinical and radiographic appearance of TB are mainly affected by the immune status of the patients. Due to the low prevalence of TB in central Europe and the wide variation of radiological presentations, the diagnosis and therapy of TB is often delayed. In this article, the radiographic manifestations of thoracic TB are summarized and discussed. STANDARD RADIOLOGICAL METHODS: Together with the medical history and bacteriological tests, chest X­ray imaging and computed tomography (CT) play a major role not only in the detection of TB but also in the follow-up during and after therapy. PRACTICAL RECOMMENDATIONS: Chest X­radiographs should be the primary diagnostic method in patients with suspected TB in screening as well as for diagnosis and therapy monitoring. The use of CT is more sensitive than chest radiographs and is frequently performed after chest radiographs to obtain detailed information about subtle parenchymal changes or lymph node manifestation. When active TB is suspected CT should be performed. Tree in bud, lobular consolidations, centrilobular nodules, cavities and ground-glass opacification are typical changes in active TB.

[Many faces of sarcoidosis]. / Die vielen Gesichter der Sarkoidose.

Sarcoidosis is a systemic, inflammatory, granulomatous disease of unknown origin that can involve any organ. More than 90% of patients have thoracic sarcoidosis, which most frequently presents with bilateral hilar lymphadenopathy. In approximately 20% of patients with thoracic sarcoidosis there is involvement of the lung parenchyma as well as mostly asymptomatic cardiac sarcoidosis in up to 55% of patients. Most patients are asymptomatic and the diagnosis is an incidental finding on chest X-ray or during clarification of unspecific symptoms, such as fatigue or cough. In approximately two thirds of patients the disease undergoes spontaneous remission and in one third the disease follows a chronic or even progressive course. Furthermore, sarcoidosis can also be manifested in the abdominal organs, the central nervous system (CNS) and the musculoskeletal system. These manifestations are frequently subclinical and require targeted diagnostics when sarcoidosis is clinically suspected.

[Protection of the unborn child in diagnostic and interventional radiological procedures]. / Schutz des ungeborenen Lebens bei diagnostischen und interventionellen radiologischen Verfahren.

The radiation exposure of an unborn child should be principally avoided, whenever it is medically reasonably possible; therefore, the identification of pregnant patients is the first and the most important step in radiation protection of the unborn child. However, in cases of emergency saving the life of the patient has a higher priority than the radiation protection of the unborn child. In this review article, we present a longitudinal section through the national and international literature and guidelines as a basis for radiological management of a (possibly) pregnant patient. We also list some radiological procedures recommended in the literature for a series of maternal indications considering the contraindications of each method during pregnancy and radiation protection of the unborn child.

[Imaging of blunt chest trauma]. / Bildgebung des stumpfen Thoraxtraumas.

CLINICAL/METHODOLOGICAL ISSUE: Blunt chest trauma is associated with high morbidity and mortality. Consequently, all patients should be evaluated radiologically after blunt chest trauma to allow timely and appropriate treatment. STANDARD RADIOLOGICAL METHODS: Conventional chest radiographs and computed tomography (CT) are proven modalities with which to evaluate patients after blunt chest trauma. METHODOLOGICAL INNOVATIONS: Over the last several years extended focused assessment with sonography for trauma (eFAST) has gained increasing importance for the initial assessment of seriously injured patients. PRACTICAL RECOMMENDATIONS: In the acute phase of severely injured patients eFAST examinations are helpful to exclude pneumothorax, hemothorax and hemopericardium. Chest radiographs may also be used to diagnose a pneumothorax or hemothorax; however, the sensitivity is limited and CT is the diagnostic modality of choice to evaluate severely injured patients.

[The importance of risk models for management of pulmonary nodules]. / Die Bedeutung von Risikomodellen für das Management pulmonaler Rundherde.

CLINICAL/METHODICAL ISSUE: Pulmonary nodules are a frequent finding in computed tomography (CT) investigations. STANDARD RADIOLOGICAL METHODS: Further diagnostic work-up of detected nodules mainly depends on the so-called pre-test probability, i.e. the probability that the nodule is malignant or benign. METHODICAL INNOVATIONS: The pre-test probability can be calculated by combining all relevant information, such as the age and the sex of the patient, the smoking history, and history of previous malignancies, as well as the size and CT morphology of the nodule. PERFORMANCE: If additional investigations are performed to further investigate the nodules, all results must be interpreted taking into account the pre-test probability and the test performance of the investigation in order to estimate the post-test probability. ACHIEVEMENTS: In cases with a low pre-test probability, a negative result from an exact test can exclude malignancies but a positive test cannot prove malignancy in such a setting. In cases with a high pre-test probability, a positive test result can be considered as proof of malignancy but a negative test result does not exclude malignancy.

[Management of subsolid pulmonary nodules]. / Management subsolider pulmonaler Rundherde.

The finding of subsolid pulmonary nodules poses a frequent problem in the daily routine of the radiologist. The biological behavior of such subsolid lesions differs significantly from solid nodules. The risk of malignancy is significantly higher in subsolid nodules as compared to solid or purely ground glass opacities or nodules. The recommendations regarding the diagnostic management of subsolid nodules have been adapted according to the tendency of growth and the risk of malignancy. A benign etiology is also seen quite often in subsolid lesions and in this case they will show a reduction of size or disappear completely by the follow-up examination. Therefore, in many cases a short-term follow-up examination is primarily recommended. As the findings will often show no changes for a long period of time, further annual follow-up examinations over a longer, not yet specified period of time are recommended. Subsolid lesions that grow in size and/or show an increase in density or develop a solid part within a ground glass lesion should remain as suspected malignancies until proven otherwise.

[Lung cancer screening. What have we learnt for the practice so far?]. / Bronchialkarzinomscreening. Was haben wir für die Praxis bisher gelernt?

CLINICAL/METHODICAL ISSUE: Lung cancer is the most frequent cause of tumor-associated death and only has a good prognosis if detected at a very early tumor stage. METHODICAL INNOVATIONS: For the first time the American National Lung Screening Trial (NLST) could prove that low-dose computed tomography (CT) screening is able to reduce lung cancer mortality by 20 %. PERFORMANCE: To date, however, three much smaller and therefore statistically underpowered European trials could not confirm the positive results of the NLST. The results of the largest European trial NELSON are expected within the next 2 years. In addition, there are a number of open or not yet satisfactorily answered questions, such as the definition of the appropriate screening population, the management of nodules detected by screening, the effects of over-diagnosis and the risk of cumulative radiation exposure. PRACTICAL RECOMMENDATIONS: The success of the NLST prompted several predominantly American professional societies to issue a positive recommendation about the implementation of lung cancer screening in a population at risk. However, potentially conflicting results of European studies and a number of not yet optimized issues justify caution and call for a pooled analysis of European studies in order to provide statistically sound results and to ensure a high efficiency of screening with respect to the radiation applied, mental and physical patient burden and, last but not least, the financial efforts.

Evolution of continuing medical education in radiology: on-site vs remote.

OBJECTIVES: To assess the evolution of continuing medical education/continuous professional development (CME/CPD) in European Radiology with a particular focus on on-site (live educational events, LEE) vs remote (electronic learning materials, ELM) participation and the impact of the COVID-19 pandemic. METHODS: Results related to CME/CPD of surveys conducted by the Accreditation Council of Imaging (ACI) between 2017 and 2020 are summarized. Additional insights from the survey conducted in spring 2023, exploring online education trends since the start of the COVID-19 pandemic, are presented. Finally, the results of the surveys are correlated with the total number of CME/CPD applications received annually from 2018 to 2022. RESULTS: Pre-pandemic, 90% of European radiologists supported mandatory CME and unified CME/CPD-system. A trend among younger radiologists towards ELM was observed. Only 20% of employers fully endorsed CME/CPD. In 2020, LEE attendance dropped significantly (95.5-33%), with a simultaneous surge (33-58%) in time spent on ELM. Post-pandemic, the majority (52%) of LEE attendees participated in 1-5 events, whereas the majority (38%) of attendees of live-streamed events participated in 6-20 meetings. Content remains a priority of respondents in all formats: 79% for online, 75% for on-site, and 74% for on-demand. While the assessed quality of LEE remained at the same level (no change (36%) or good/very good (48%)), a considerably higher percentage of respondents noticed the quality of live-streamed events was good/very good (83%). CONCLUSION: The majority of European radiologists support mandatory CME and a unified CME/CPD system. Despite the post-pandemic resurgence in LEE, ELM and hybrid events are predicted to gain further prominence. CRITICAL RELEVANCE STATEMENT: The CME/CPD system dynamically adapts to evolving professional, technical, and environmental circumstances, with human interaction gaining heightened significance post-COVID-19. KEY POINTS: Professionals expressed a desire to return to on-site participation, highlighting its desirability for social interaction. Electronic learning materials are poised for continued growth, particularly among younger generations. Professionals expressed a desire towards a unified CME/CPD system in Europe.

PD-L1 expression in patients with non-small-cell lung cancer is associated with sex and genetic alterations: A retrospective study within the Caucasian population.

BACKGROUND: Programmed cell death-ligand 1 (PD-L1) expression is a well-established biomarker for predicting responses to immune checkpoint inhibitors and certain targeted therapies. As a result, treatment strategies for patients vary based on their PD-L1 expression status. Understanding the clinical features of patients with distinct PD-L1 levels is crucial for personalized treatment approaches. METHODS: Demographic and clinicopathological characteristics of 227 patients (54% male, mean age 67 ± 9.9 years) newly diagnosed with non-small-cell lung cancer (NSCLC) between April 2020 and December 2022 were retrospectively compared among three groups based on the PD-L1 expression: PD-L1 Tumor Proportion Score (TPS) negative, 1-50%, and ≥50%. Logistic regression analysis was performed to evaluate predictors for high PD-L1 expression ≥50%. RESULTS: PD-L1 expression levels were distributed as follows: negative in 29% of patients, between 1% and 50% in 41%, and greater than 50% (high) in 29%. In comparison to negative PD-L1 expression, low and high PD-L1 expression was associated with female sex (32.9% vs. 52.7% vs. 50.7%, p = 0.031), with the absence of epidermal growth factor receptor (EGFR) mutations (83.6% vs. 91.1% vs. 98.1% p = 0.029), and with the absence of ERBB2 (HER2) tyrosine kinase mutations (90.9% vs. 100% vs. 98.1% p = 0.007), respectively. Age, smoking status, histological subtype, and disease stage showed no significant differences among the three patient groups. In the univariate logistic regression, EGFR mutation appeared to be the only predictor for PD-L1 expression, although it did not reach statistical significance (p = 0.06). CONCLUSION: Although sex and genomic alterations are associated with PD-L1 expression in patients with NSCLC, no clinical characteristics seem to predict PD-L1 expression significantly.

[Radiological evaluation of incidental pulmonary nodules]. / Radiologische Abklärung inzidenteller pulmonaler Rundherde.

Since the widespread use of computed tomography (CT), the detection of pulmonary nodules has considerably increased and has become part of the daily clinical routine. In the evaluation of pulmonary nodules, malignant nodules have to be differentiated from benign pulmonary nodules with a high level of confidence. The diagnostic approach for pulmonary nodules depends on the pretest probability for malignancy. For indeterminate pulmonary nodules <8 mm, non-contrast CT observational follow-up is recommended and depending on the size and pretest probability for malignancy, follow-up CT intervals range from 3 to 12 months. For indeterminate pulmonary nodules >8 mm, management is based on patient surgical risk and pretest probability for malignancy. Either CT follow-up alone, 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) or non-surgical biopsy for tissue diagnosis are utilized to evaluate the lesions. For pulmonary nodules with a high pretest probability for malignancy, surgical resection is recommended unless specifically contraindicated.

[Oncologic imaging: indications for and limitations of modern cross-sectional imaging techniques]. / Bildgebende Methoden in der onkologischen Diagnostik: Indikationen und Limitationen moderner Schnittbildverfahren.

Cross-sectional imaging techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) CT are an integral part of the modern oncological workup. They are used for tumor detection and staging as well as for treatment evaluation and monitoring. Due to pathophysiological and histological differences there is no universal imaging protocol for the assessment of different forms of cancer. For instance, CT is still the standard technique for the detection and staging of lung cancer supplemented by PET which aids the exclusion of nodal involvement and the detection of distant metastases. For hepatocellular carcinoma on the other hand, MRI is the preferred imaging technique, particularly when used in conjunction with liver-specific contrast media - PET/CT is only of limited value. Finally, for neuroendocrine tumors there is a focus on special radiotracers, which, in the context of PET/CT, enable a highly specific whole-body assessment. Thus, knowledge of the pathophysiological and imaging characteristics of different tumors is essential for a personalized, state-of-the art management of oncology patients.