Miliary Nodules in the Lungs Not Always Due to Tuberculosis: A Report of a Rare Case

Allergic bronchopulmonary aspergillosis (ABPA) is a disease that occurs due to a pulmonary immune system reaction to the antigens of Aspergillus Fumigatus. Central bronchiectasis, mucoid impaction, mosaic attenuation, centrilobular nodules, and tree-in-bud opacities are the most commonly observed CT scan findings of ABPA. Miliary molting is one of the rare radiological manifestations of ABPA. ABPA is usually seen in uncontrolled asthma and is very uncommon in patients without a prior history of asthma. We are reporting a case of ABPA that presented a miliary nodule in radiology and was never diagnosed as a case of asthma previously. Thus, in a patient with eosinophilia and miliary molting, ABPA is to be excluded. Early diagnosis and treatment can prevent end-stage fibrotic ABPA.

How accurate is high-resolution computed tomography of the chest in differentiating between pulmonary invasive fungal infections and other pulmonary infections in children with cancer?

BACKGROUND

Pulmonary invasive fungal infections pose a serious risk for immunocompromised patients. Although diagnostic imaging plays an important role in the early detection of pulmonary invasive fungal infections, radiological differentiation between invasive fungal infection and other pulmonary infections is challenging.

OBJECTIVE

The aim of this study was to assess the accuracy of chest high-resolution computed tomography (HRCT) in the differentiation between pulmonary invasive fungal infections and other pulmonary infections in paediatric cancer patients.

MATERIALS AND METHODS

In this retrospective study, baseline HRCTs of patients with probable or proven invasive fungal infections and other pulmonary infections were blindly assessed by two radiologists, followed by a consensus reading. The scoring form included imaging characteristics and radiological invasive fungal infection probability assessment. Inter-rater reliability was determined with Cohen's kappa.

RESULTS

Chest HRCTs (n = 77) of paediatric cancer patients with pulmonary invasive fungal infections (n = 45) and with other pulmonary infections (n = 32) were evaluated. In the consensus reading, nodules with halo sign and wedge-shaped consolidations were observed significantly more in pulmonary invasive fungal infections than in other pulmonary infections (86.7% vs. 34.4% and 28.9% vs. 9.4%), and ground-glass opacities were observed less frequently (61.4% vs. 87.5%). The kappa values for the individual imaging characteristics ranged from 0.121 to 0.408. Sensitivity of the HRCT to diagnose a pulmonary invasive fungal infection ranged from 0.78 to 0.80, and specificity from 0.66 to 0.88.

CONCLUSION

The accuracy of chest HRCTs in differentiating between invasive fungal infections and other pulmonary infections is poor. There are two main reasons for this: no individual imaging characteristic was found to be able to fully distinguish between invasive fungal infections and other pulmonary infections, and the agreement between radiologists was only moderate.

Impact of Herpesvirus Detection via Metagenomic Next-Generation Sequencing in Patients with Lower Respiratory Tract Infections

Purpose

This study aimed to investigate the impact of herpesvirus detection by metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) on lower respiratory tract infections (LRTIs) patients' lung microbiome composition and prognosis.

Patients and methods

We initially enrolled 234 hospitalized patients with LRTIs who underwent BALF mNGS between February 2022 and May 2023. The study analyzed the clinical manifestations and the pulmonary microbial composition between herpesvirus detection (HD) and non-herpesvirus detection (non-HD) group.

Results

After exclusions, a total of 201 patients were included, out of which 73 patients had herpesvirus detections (HD). The most frequently detected herpesviruses were Human herpesvirus 7 (HHV-7) (19.4%), Epstein-Barr virus (EBV) (12.4%), and cytomegalovirus (CMV) (10.4%). The HD group had a higher proportion of male patients (78.08% vs 55.04%, P = 0.001) and a greater incidence of hemoptysis and multilobar infiltrates compared non-HD group. Additionally, the HD group tended to have longer hospital stays compared to non-HD group, especially in immunosuppressed patients. Furthermore, in immunocompetent patients, there were significant differences in α diversity and β diversity between the HD group and non-HD group, but such differences were not observed in immunosuppressed patients.

Conclusion

The presence of herpesvirus in patients with non-critical LRTI is associated with longer hospital stays and alterations in the lung's microbial composition. Additionally, the impacts of herpesvirus presence are influenced by the immune status of the patients.

Debunking a mythology: Atelectasis is not a cause of postoperative fever

Most physicians appreciate that practicing medicine is a commitment to continuous learning. However, "learning" can be mistakenly understood as simply the acquisition of facts and new knowledge. But learning also necessitates the constant re-examination and challenging of one's existing body of knowledge, as misinformation persists when one's beliefs are not challenged or questioned in the light of new information. One example is the pervasive belief that postoperative atelectasis causes fever despite ample evidence to the contrary. Herein we examine the imaging characteristics of atelectasis, and the means of differentiation of atelectasis from consolidation. We also explore the history of this persistent myth and review the existing literature on the actual causes of postoperative fever.

Emergency imaging protocols for pregnant patients: a multi-institutional and multi- specialty comparison of physician education

PURPOSE

Previous studies have demonstrated that radiologists and other providers perceive the teratogenic risks of radiologic imaging to be higher than they actually are. Thus, pregnant patients were less likely to receive ionizing radiation procedures. While it is imperative to minimize fetal radiation exposure, clinicians must remember that diagnostic studies should not be avoided due to fear of radiation, particularly if the imaging study can significantly impact patient care. Although guidelines do exist regarding how best to image pregnant patients, many providers are unaware of these guidelines and thus lack confidence when making imaging decisions for pregnant patients. This study aimed to gather information about current education, confidence in, and knowledge about emergency imaging of pregnant women among radiology, emergency medicine, and OB/GYN providers.

METHODS

We created and distributed an anonymous survey to radiology, emergency medicine, and OB/GYN providers to evaluate their knowledge and confidence in imaging pregnant patients in the emergent setting. This study included a questionnaire with the intent of knowing the correct answers among physicians primarily across the United States (along with some international participation). We conducted subgroup analyses, comparing variables by specialty, radiology subspecialty, and training levels. Based on the survey results, we subsequently developed educational training videos.

RESULTS

108 radiologists, of which 32 self-identified as emergency radiologists, ten emergency medicine providers and six OB/GYN clinicians completed the survey. The overall correct response rate was 68.5%, though performance across questions was highly variable. Within our 18-question survey, four questions had a correct response rate under 50%, while five questions had correct response rates over 90%. Most responding physicians identified themselves as either "fairly" (58/124, 47%) or "very" (51/124, 41%) confident. Amongst specialties, there were differences in performance concerning the knowledge assessment (p = 0.049), with the strongest performance from radiologists. There were no differences in knowledge by training level (p = 0.4), though confidence levels differed significantly between attending physicians and trainees (p < 0.001).

CONCLUSION

This study highlights deficiencies in knowledge to support appropriate decision-making surrounding the imaging of pregnant patients. Our results indicate the need for improved physician education and dissemination of standardized clinical guidelines.

Co-Existing Fungi: An Unforeseen Combo Creating a Dilemma in Diagnostic Morale

Mucormycosis is a rare fungal infection belonging to Mucorales order fungi. Rhino-cerebral form is more noted in patients with diabetes mellitus, but pulmonary mucormycosis is a rare manifestation with hematological malignancy, malignant tumors, and transplant recipient patients. Aspergillus species are also known to cause allergic bronchopulmonary aspergillosis, aspergilloma, chronic pulmonary aspergillosis, and invasive aspergillosis in immunocompromised individuals. We report a case of pulmonary mucormycosis superimposed with aspergillus infection presenting in an immunocompromised patient with metastatic prostate cancer on chemotherapy, initially misdiagnosed as aspergillus infection.

Spectrum of Thoracic Imaging Findings in the Setting of Substance Abuse

ABSTRACT

Substance abuse continues to be prevalent nationwide and can lead to a myriad of chest pathologies. Imaging findings are vast and can include nodules, masses, ground-glass opacities, airspace disease, and cysts. Radiologists with awareness of these manifestations can assist in early identification of disease in situations where information is unable to be obtained from the patient. This review focuses on thoracic imaging findings associated with various forms of substance abuse, which are organized by portal of entry into the thorax: inhalation, ingestion, and injection.

Fleischner Society: Glossary of Terms for Thoracic Imaging

Members of the Fleischner Society have compiled a glossary of terms for thoracic imaging that replaces previous glossaries published in 1984, 1996, and 2008, respectively. The impetus to update the previous version arose from multiple considerations. These include an awareness that new terms and concepts have emerged, others have become obsolete, and the usage of some terms has either changed or become inconsistent to a degree that warranted a new definition. This latest glossary is focused on terms of clinical importance and on those whose meaning may be perceived as vague or ambiguous. As with previous versions, the aim of the present glossary is to establish standardization of terminology for thoracic radiology and, thereby, to facilitate communications between radiologists and clinicians. Moreover, the present glossary aims to contribute to a more stringent use of terminology, increasingly required for structured reporting and accurate searches in large databases. Compared with the previous version, the number of images (chest radiography and CT) in the current version has substantially increased. The authors hope that this will enhance its educational and practical value. All definitions and images are hyperlinked throughout the text. Click on each figure callout to view corresponding image. © RSNA, 2024 Supplemental material is available for this article. See also the editorials by Bhalla and Powell in this issue.

A young boy with diabetic ketoacidosis and non-resolving pneumonia

Classic radiological signs of invasive fungal disease, especially pulmonary mucormycosis in a predisposed individual should alert the physician to initiate empiric anti-fungal therapy. https://bit.ly/40gt4Hm.

Enlarging 18 F-FDG-Avid Solitary Pulmonary Nodule: A Distinctly Unusual Presentation of Cytomegalovirus Infection in a Patient Receiving Chemotherapy

ABSTRACT

Rapidly growing lung lesions, particularly in immunocompromised patients, invoke consideration of an infectious etiology. Aspergillomas, for example, can appear as round nodules with soft tissue attenuation, often associated with cavitation, and are variably 18 F-FDG avid. In contrast, cytomegalovirus, which may also evidence 18 F-FDG uptake, typically manifests as ground-glass opacities, symmetrically distributed small pulmonary nodules, or confluent consolidations, with lower lobe predilection. We describe a patient treated for lymphoma presenting with a solitary enlarging FDG-avid lung nodule, which was determined on resection to be focal cytomegalovirus infection, a distinctly uncommon presentation of this pathogen, more typical of fungal or mycobacterial disease.

Atypical imaging patterns during lung invasive mould diseases: lessons for clinicians

Imaging of pulmonary invasive mould diseases (IMDs), which represents a cornerstone in their work-up, is mainly based on computed tomography (CT). The purpose of this review is to discuss their CT features, mainly those related to aspergillosis and mucormycosis. We will especially focus on atypical radiological presentations that are increasingly observed among non-neutropenic emerging populations of patients at risk, such as those receiving novel anticancer therapies or those in the intensive care unit. We will also discuss the interest of other available imaging techniques, mainly positron emission tomography/CT, that may play a role in the diagnosis as well as evaluation of disease extent and follow-up. We will show that any new airway-centred abnormality or caveated lesion should evoke IMDs in mildly immunocompromised hosts. Limitations in their recognition may be due to potential underlying abnormalities that increase the complexity of interpretation of lung imaging, as well as the non-specificity of imaging features. In this way, the differentials of all morphological/metabolic aspects must be kept in mind for the optimal management of patients, as well as the benefit of evaluation of the vascular status.

Imaging in Lung Transplantation: Surgical Techniques and Complications

Lung transplant is an established treatment for patients with end-stage lung disease. As a result, there is increased demand for transplants. Despite improvements in pretransplant evaluation, surgical techniques, and postsurgical care, the average posttransplant life expectancy is only around 6.5 years. Early recognition of complications on imaging and treatment can improve survival. Knowledge of surgical techniques and imaging findings of surgical and nonsurgical complications is essential. This review covers surgical techniques and imaging appearance of postsurgical and nonsurgical complications, including allograft dysfunction, infections, neoplasms, and recurrence of primary lung disease.

Clinicopathological and Radiological Features of Cats Presented with Infectious Respiratory Disease Signs: A Focus on Rhodococcus equi and Klebsiella pneumoniae

The objective of this study was to evaluate the prevalence of involvement of common viral organisms R. equi and K. pneumoniae and their clinicopathological and radiological features in respiratory disease of Malaysian domestic cats. A total of 34 feline cases with acute/chronic infectious respiratory disease signs were followed prospectively to investigate respiratory disease due to R. equi and K. pneumoniae and their relationship with concurrent viral infections in disease manifestation. All sampled cats (n = 27) were positive for FCoV antibodies and negative for FeLV. A significantly high antibody titer for FCV in n = 26 cases was also noticed. A single sample of pyothorax from a 3-months-old, non-vaccinated kitten was positive for R. equi. Bronchopneumonia with severe infiltration of the polymorphs and mononuclear inflammatory cells were prominent features of lungs histopathology from the kitten positive for R. equi. K. pneumoniae subsp. pneumoniae was confirmed from tracheal swabs of two cats. Histologically, the tracheal tissues of the two cats positive for K. pneumoniae were normal. In diagnostic imaging, epicenter of the infectious URT disease was nasal conchae rostrally and nasal turbinates caudally, however for infectious LRT disease was bronchial tree. Conclusively, infectious respiratory disease is a complex illness in cats, predominantly for unvaccinated kittens and young adult cats, especially those kept in multi-cat household or shelter environments because of the involvement of multiple bacterial and viral organisms as primary or secondary invaders. Clinicians should not preclude feline rhodococcosis from differentials, especially in kittens with pyothorax and less than one year of age. Unlike R. equi, K. pneumoniae has the potential to colonize URT of cats which might be disseminating further to cause LRT disease.

Emerging complications of COVID-19 in a subset of Indian population: a pathological review with clinico-radiological case scenarios

Background

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was declared a pandemic by the World Health Organization on 11 March 2020 has been reported in most countries around the world since its origins in Wuhan, China. As of September 2021, there have been over 229 million cases of COVID-19 reported worldwide, with over 4.7 million COVID-19–associated deaths.

Body

The devastating second wave of the COVID-19 pandemic in India has seen a rise in various extrapulmonary manifestations. One of key components in the pathogenesis of COVID-19 is downregulation of ACE-2, which is expressed on many organs and counterbalances the pro-inflammatory effects of ACE/angiotensin-II axis. This leads to influx of inflammatory cells into alveoli, increased vascular permeability and activation of prothrombotic mediators. Imaging findings such as ground glass opacities, interlobular septal thickening, vascular dilatation and pulmonary thrombosis correlate well with the pathogenesis.

Conclusion

We hypothesize that the systemic complications of COVID-19 are caused by either direct viral invasion or effect of cytokine storm leading to inflammation and thrombosis or a combination of both. Gaining insights into pathobiology of SARS-CoV-2 will help understanding the various multisystemic manifestations of COVID-19. To date, only a few articles have been published that comprehensively describe the pathophysiology of COVID-19 along with its various multisystemic imaging manifestations.

Epidemiology of community-acquired pneumonia among hospitalised children in Indonesia: a multicentre, prospective study

OBJECTIVE

To identify aetiologies of childhood community-acquired pneumonia (CAP) based on a comprehensive diagnostic approach.

DESIGN

'Partnerships for Enhanced Engagement in Research-Pneumonia in Paediatrics (PEER-PePPeS)' study was an observational prospective cohort study conducted from July 2017 to September 2019.

SETTING

Government referral teaching hospitals and satellite sites in three cities in Indonesia: Semarang, Yogyakarta and Tangerang.

PARTICIPANTS

Hospitalised children aged 2-59 months who met the criteria for pneumonia were eligible. Children were excluded if they had been hospitalised for >24 hours; had malignancy or history of malignancy; a history of long-term (>2 months) steroid therapy, or conditions that might interfere with compliance with study procedures.

MAIN OUTCOMES MEASURES

Causative bacterial, viral or mixed pathogen(s) for pneumonia were determined using microbiological, molecular and serological tests from routinely collected specimens (blood, sputum and nasopharyngeal swabs). We applied a previously published algorithm (PEER-PePPeS rules) to determine the causative pathogen(s).

RESULTS

188 subjects were enrolled. Based on our algorithm, 48 (25.5%) had a bacterial infection, 31 (16.5%) had a viral infection, 76 (40.4%) had mixed bacterial and viral infections, and 33 (17.6%) were unable to be classified. The five most common causative pathogens identified were Haemophilus influenzae non-type B (N=73, 38.8%), respiratory syncytial virus (RSV) (N=51, 27.1%), Klebsiella pneumoniae (N=43, 22.9%), Streptococcus pneumoniae (N=29, 15.4%) and Influenza virus (N=25, 13.3%). RSV and influenza virus diagnoses were highly associated with Indonesia's rainy season (November-March). The PCR assays on induced sputum (IS) specimens captured most of the pathogens identified in this study.

CONCLUSIONS

Our study found that H. influenzae non-type B and RSV were the most frequently identified pathogens causing hospitalised CAP among Indonesian children aged 2-59 months old. Our study also highlights the importance of PCR for diagnosis and by extension, appropriate use of antimicrobials.

TRAIL REGISTRATION NUMBER

NCT03366454.

Fungal infection mimicking COVID-19 infection - A case report

For the last 2 years, one of the most frequent causes of respiratory failure is coronavirus disease 2019 (COVID-19). The symptoms are not specific. Imaging diagnostics, especially high-resolution computed tomography, is a diagnostic method widely used in the diagnosis of this disease. It is important to emphasize that not only SARS-CoV-2 infection may manifest as interstitial pneumonia. Other diseases such as other viral, fungal, atypical bacterial pneumonia, autoimmune process, and even cancer can also manifest as ground-glass opacities or consolidations in the imaging of the lungs. In this case report, we described a patient who manifested many symptoms that seemed to be COVID-19. However, all performed antigen and polymerase chain reaction tests were negative. The diagnostics must have been extended. Microbiological and mycological blood cultures and sputum cultures were performed. Blood cultures were negative but in sputum, Candida albicans and Candida glabrata were identified. Targeted therapy with fluconazole was implemented with a satisfactory result. The patient was discharged from the hospital in a good general condition with no complaints.

Case Report: A Case of Acute T Lymphoblastic Leukemia With Mixed Infection of Lethal Invasive Mucormycosis and Multi-Drug Resistant Bacteria

Pulmonary mucormycosis (PM) is a rare and life-threatening fungal infection. Here, we report a case of an acute T lymphoblastic leukemia patient with mixed infections of lethal invasive Mucormycosis and multi-drug resistant (MDR) bacteria. After receiving anti-infection drugs to control the patient's fever, he was treated with induction chemotherapy. However, the malignant hematological disease was poorly controlled by the chemotherapy and the patient developed more symptoms of infection. Although the results of multiple β-D-Glucan (G) and Galactomannan (GM) tests remained negative, several pathogens were detected using metagenomic next-generation sequencing (mNGS). In particular, mNGS identified Malassezia pachydermum, Mucor racemosus, and Lauteria mirabilis in the peripheral blood and local secretion samples. The Mucor and bacterial infections were further confirmed via multi-site and repeated fungal and bacterial cultures, respectively. Despite adjusting the anti-infection therapy according to the diagnostic results, the patient's blood disease and symptoms of infection were not alleviated. Additionally, the MDR Acinetobacter baumannii infection/colonization was not confirmed until the seventh culture of the peripheral venous catheter tip. Due to the patient's deteriorating conditions, his family decided to withdraw him from further treatment. Overall, mNGS can facilitate a diagnosis of Mucormycosis by providing clinical and therapeutic information to support conventional diagnostic approaches. For the early and timely diagnosis and treatment of PM, it is also necessary to consider the malignant hematological conditions and repeated tests through multiple detection methods.

CT after Lung Microwave Ablation: Normal Findings and Evolution Patterns of Treated Lesions

Imaging-guided percutaneous ablative treatments, such as radiofrequency ablation (RFA), cryoablation and microwave ablation (MWA), have been developed for the treatment of unresectable primary and secondary lung tumors in patients with advanced-stage disease or comorbidities contraindicating surgery. Among these therapies, MWA has recently shown promising results in the treatment of pulmonary neoplasms. The potential advantages of MWA over RFA include faster ablation times, higher intra-tumoral temperatures, larger ablation zones and lower susceptibility to the heat sink effect, resulting in greater efficacy in proximity to vascular structures. Despite encouraging results supporting its efficacy, there is a relative paucity of data in the literature regarding the role of computer tomography (CT) to monitor MWA-treated lesions, and the CT appearance of their morphologic evolution and complications. For both interventional and non-interventional radiologists, it is crucial to be familiar with the CT features of such treated lesions in order to detect incomplete therapy or recurrent disease at early stage, as well as to recognize initial signs of complications. The aim of this pictorial essay is to describe the typical CT features during follow-up of lung lesions treated with percutaneous MWA and how to interpret and differentiate them from other radiological findings, such as recurrence and complications, that are commonly encountered in this setting.

[Pulmonary nodules and pneumonia : A diagnostic guideline]

Hintergrund

Das konventionelle Röntgenbild zählt zu den am häufigsten durchgeführten radiologischen Untersuchungen. Seine Interpretation gehört zu den Grundkenntnissen jedes Radiologen.

Fragestellung

Ziel dieses Artikels ist es, häufige Zeichen und Muster der Pneumonie sowie Merkmale von Pseudoläsionen im konventionellen Röntgenbild zu erkennen und einen diagnostischen Leitfaden für junge Radiologen zu schaffen.

Methoden

Analyse aktueller Studien und Daten sowie eine Übersicht der häufigsten Zeichen und Muster im konventionellen Röntgenbild.

Ergebnisse

Die Kenntnis über häufige Zeichen und Muster im Röntgenbild bietet eine Hilfestellung in der Diagnostik und kann hinweisend für die Ursache einer Infektion sein. Häufig sind diese Zeichen jedoch unspezifisch und sollten daher immer in klinische Korrelation gesetzt werden. In der Detektion und Beurteilung von pulmonalen Rundherden gewinnt die Computertomographie (CT) durch ihre deutlich höhere Sensitivität in der Primärdiagnostik immer mehr an Bedeutung.

Schlussfolgerung

Das konventionelle Röntgenbild bildet weiterhin eine führende Rolle in der Primärdiagnostik; der Radiologe sollte jedoch die Limitationen des konventionellen Bildes kennen.

Deep diagnostic agent forest (DDAF): A deep learning pathogen recognition system for pneumonia based on CT

BACKGROUND

Even though antibiotics agents are widely used, pneumonia is still one of the most common causes of death around the world. Some severe, fast-spreading pneumonia can even cause huge influence on global economy and life security. In order to give optimal medication regimens and prevent infectious pneumonia's spreading, recognition of pathogens is important.

METHOD

In this single-institution retrospective study, 2,353 patients with their CT volumes are included, each of whom was infected by one of 12 known kinds of pathogens. We propose Deep Diagnostic Agent Forest (DDAF) to recognize the pathogen of a patient based on ones' CT volume, which is a challenging multiclass classification problem, with large intraclass variations and small interclass variations and very imbalanced data.

RESULTS

The model achieves 0.899 ± 0.004 multi-way area under curves of receiver (AUC) for level-I pathogen recognition, which are five rough groups of pathogens, and 0.851 ± 0.003 AUC for level-II recognition, which are 12 fine-level pathogens. The model also outperforms the average result of seven human readers in level-I recognition and outperforms all readers in level-II recognition, who can only reach an average result of 7.71 ± 4.10% accuracy.

CONCLUSION

Deep learning model can help in recognition pathogens using CTs only, which might help accelerate the process of etiological diagnosis.

[Common infectious challenges of the thoracic and lumbar spine : Spondylodiscitis and postoperative wound infection]

Spondylodiscitis and postoperative wound infections are the most frequent infectious diseases of the thoracic and lumbar spine. Every spinal surgeon will come into contact with such patients during his or her career. Knowledge particularly of the diagnostics, conservative and surgical treatment as well as microbiological considerations of antibiotic treatment are therefore of particular importance and are explained in this article.

Complications of Lung Transplantation: Update on Imaging Manifestations and Management

As lung transplantation has become the most effective definitive treatment option for end-stage chronic respiratory diseases, yearly rates of this surgery have been steadily increasing. Despite improvement in surgical techniques and medical management of transplant recipients, complications from lung transplantation are a major cause of morbidity and mortality. Some of these complications can be classified on the basis of the time they typically occur after lung transplantation, while others may occur at any time. Imaging studies, in conjunction with clinical and laboratory evaluation, are key components in diagnosing and monitoring these conditions. Therefore, radiologists play a critical role in recognizing and communicating findings suggestive of lung transplantation complications. A description of imaging features of the most common lung transplantation complications, including surgical, medical, immunologic, and infectious complications, as well as an update on their management, will be reviewed here. Keywords: Pulmonary, Thorax, Surgery, Transplantation Supplemental material is available for this article. © RSNA, 2021.

Managing Incidental Findings on Thoracic CT: Lung Findings. A White Paper of the ACR Incidental Findings Committee

The ACR Incidental Findings Committee presents recommendations for managing incidentally detected lung findings on thoracic CT. The Chest Subcommittee is composed of thoracic radiologists who endorsed and developed the provided guidance. These recommendations represent a combination of current published evidence and expert opinion and were finalized by informal iterative consensus. The recommendations address commonly encountered incidental findings in the lungs and are not intended to be a comprehensive review of all pulmonary incidental findings. The goal is to improve the quality of care by providing guidance on management of incidentally detected thoracic findings.

[Imaging in respiratory infections]

The conventional X‑ray image is the method of choice for suspected pneumonia. Computed tomography (CT) is indicated for treatment refractory or recurrent infiltrates, difficult differential diagnostics, suspected complications and in immunocompromised patients. Thoracic sonography can be used as an alternative method for initial diagnostics and in the intensive care unit to monitor progress. In addition to the detection of infiltrates the radiological classification can help to limit the pathogen spectrum. Radiologically, three forms of pneumonia can principally be differentiated: lobar pneumonia, bronchopneumonia and interstitial pneumonia. Furthermore, there are special forms of pneumonia with certain pathogens, such as aspergilloma, invasive mycosis, postprimary tuberculosis and nontuberculous mycobacteriosis or in a specific clinical context, such as aspiration pneumonia, postinfarction pneumonia, retention pneumonia and septic emboli. The most frequent complications of pneumonia are lung abscesses and pleural empyema. Both can sometimes but not always be seen in the X‑ray image. If clinically suspected the indications for CT should be generously applied. Certain pre-existing diseases, such as immunodeficiency or structural alterations of the lungs can predispose to pulmonary infections, frequently with unusual pathogens or manifestation forms and must be taken into account in the diagnostics.

Consolidated lung on contrast-enhanced chest CT: the use of spectral-detector computed tomography parameters in differentiating atelectasis and pneumonia

Objectives

To investigate the value of spectral-detector computed tomography (SDCT) parameters for the quantitative differentiation between atelectasis and pneumonia on contrast-enhanced chest CT.

Material and methods

Sixty-three patients, 22 clinically diagnosed with pneumonia and 41 with atelectasis, underwent contrast-enhanced SDCT scans during the venous phase. CT numbers (Hounsfield Units [HU]) were measured on conventional reconstructions (CON_120kVp) and the iodine concentration (C_iodine, [mg/ml]), and effective atomic number (Z_eff) on spectral reconstructions, using region-of-interest (ROI) analysis. Receiver operating characteristics (ROC) and contrast-to-noise ratios (CNRs) were calculated to assess each reconstruction's potential to differentiate between atelectasis and pneumonia.

Results

On contrast-enhanced SDCT, the difference between atelectasis and pneumonia was significant on CON_120kVp, C_iodine, and Z_eff images (p < 0.001). On CON_120kVp images, a threshold of 81 HU achieved a sensitivity of 93 % and a specificity of 95 % for identifying pneumonia, while C_iodine and Z_eff images reached the same sensitivity but lower specificities of 85 % and 83 %. CON_120kVp images showed significantly higher CNRs between normal lung and atelectasis or pneumonia with 30.63 and 27.69 compared to C_iodine images with 3.54 and 1.27 and Z_eff images with 4.22 and 7.63 (p < 0.001). None of the parameters could differentiate atelectasis and pneumonia without contrast media.

Conclusions

Contrast-enhanced SDCT can differentiate atelectasis and pneumonia based on the spectral parameters C_iodine, and Z_eff. However, they had no added value compared to CT number measurement on CON_120kVp images. Furthermore, contrast media is still needed for a differentiation based on quantitative SDCT parameters.

Differential diagnoses of COVID-19 pneumonia: the current challenge for the radiologist-a pictorial essay

BACKGROUND

COVID-19 pneumonia represents the most severe pandemic of the twenty-first century and has crucial clinical, social and economical implications. The scientific community has focused attention and resources on clinical and radiological features of COVID-19 pneumonia. Few papers analysing the vast spectrum of differential diagnoses have been published.

MAIN BODY

Complexity of differential diagnosis lays in the evidence of similar radiological findings as ground-glass opacities, crazy paving pattern and consolidations in COVID-19 pneumonia and a multitude of other lung diseases. Differential diagnosis is and will be extremely important during and after the pandemic peak, when there are fewer COVID-19 pneumonia cases. The aim of our pictorial essay is to schematically present COVID-19 pneumonia most frequent differential diagnoses to help the radiologist face the current COVID-19 pneumonia challenge.

CONCLUSIONS

Clinical data, laboratory tests and imaging are pillars of a trident, which allows to reach a correct diagnosis in order to grant an excellent allocation of human and economical resources. The radiologist has a pivotal role in the early diagnosis of COVID-19 pneumonia because he may raise suspicion of the pathology and help to avoid COVID-19 virus spread.

Cohort study of patients with Stevens-Johnson syndrome and toxic epidermal necrolysis in China: evaluation of risk models and new predictor of pulmonary consolidation on computed tomography

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but severe diseases. This study aimed to validate the predictive ability of risk models in patients with SJS/TEN and propose possible refinement in China. Patients in the Department of Dermatology of Huashan Hospital from January 2008 to January 2019 were included. Results showed that the severity-of-illness score for TEN (SCORTEN) had a good discrimination (area under the receiver operating characteristic curve (AUC), 0.78), and it was superior to auxiliary score (AS) and ABCD-10, which indicates age, bicarbonate level, cancer, dialysis, and 10% involved body surface area (AUC, 0.69 and 0.68, respectively). The calibration of SCORTEN (Hosmer-Lemeshow goodness-of-fit test, P = 0.69) was also better than that of AS (P = 0.25) and ABCD-10 (P = 0.55). SCORTEN and ABCD-10 were similar (Brier score (BS), 0.04 and 0.04) in terms of accuracy of predictions. In addition, the imaging appearance of pulmonary consolidation on computed tomography was associated with high mortality. Refined models were formed using the variables and this imaging appearance. The refined AS and ABCD-10 models were similar in discrimination compared with the original SCORTEN (0.74 vs. 0.78, P = 0.23; 0.74 vs. 0.78, P = 0.30, respectively). Therefore, SCORTEN showed good discrimination performance, calibration, and accuracy, and refined AS or ABCD-10 model may be an option when SCORTEN variables are not available.

The novel coronavirus pneumonia (COVID-19): a pictorial review of chest CT features

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first reported in Wuhan, China. The infection rapidly spread to more than 200 countries around the world. The clinical presentation of the disease may vary from mild illness to severe pneumonia such as acute respiratory distress syndrome (ARDS). The chest computed tomography (CT) has an important complementary role in diagnosis of the disease. The predominant CT findings of the disease are ground glass opacities and consolidations located in subpleural areas of lower lobes. Widespread ground-glass opacities, consolidation, air bronchograms, central involvement of lung parenchyma, mediastinal lymphadenopathy are more common in patients with the severe form of the disease. CT imaging also guides in differentiation of alternative diagnosis or in assessment of associated pulmonary embolism during the course of the disease. In this pictorial review we aim to review the CT features of COVID-19 pneumonia and mention the changes throughout the disease process.

The Role of Imaging in the Management of Suspected or Known COVID-19 Pneumonia. A Multidisciplinary Perspective

Coronavirus disease (COVID-19) is an illness caused by a novel coronavirus that has rapidly escalated into a global pandemic leading to an urgent medical effort to better characterize this disease biologically, clinically, and by imaging. In this review, we present the current approach to imaging of COVID-19 pneumonia. We focus on the appropriate use of thoracic imaging modalities to guide clinical management. We also describe radiologic findings that are considered typical, atypical, and generally not compatible with COVID-19. Furthermore, we review imaging examples of COVID-19 imaging mimics, such as organizing pneumonia, eosinophilic pneumonia, and other viral infections.

Radiographic and Histopathologic Features in Sarcoidosis: A Pictorial Display

Sarcoidosis is a multisystemic granulomatous disorder that can affect virtually any organ. However, pulmonary and thoracic lymph node involvement predominates; abnormalities on chest radiographs are present in 80 to 90% of patients with sarcoidosis. High-resolution computed tomographic (HRCT) scans are superior to chest X-rays in assessing extent of disease, and some CT features may discriminate an active inflammatory component (which may be amenable to therapy) from fibrosis (for which therapy is not indicated). Typical findings on HRCT include micronodules, perilymphatic and bronchocentric distribution, perihilar opacities, and varying degrees of fibrosis. Less common findings on CT include mass-like or alveolar opacities, miliary opacities, mosaic attenuation, honeycomb cysts, and cavitation. With progressive disease, fibrosis, architectural distortion, upper lobe volume loss with hilar retraction, coarse linear bands, cysts, and bullae may be observed. We discuss the salient CT findings in patients with sarcoidosis (with a major focus on pulmonary features) and present classical radiographic and histopathological images of a few extrapulmonary sites.

Advanced pneumonic type of lung adenocarcinoma: survival predictors and treatment efficacy of the tumor

PURPOSE

To retrospectively explore the survival predictors and treatment efficacy of advanced pneumonic-type lung adenocarcinoma (P-ADC).

METHODS

Retrospective analysis of clinical data and survival follow-up was undertaken on 41 patients with advanced P-ADC from January 1, 2009, to April 30, 2019. Analysis on tumor biomarkers such as carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and the cytokeratin-19-fragment (Cyfra21-1) were undertaken. The patients in this study were divided into three groups based on usage of tyrosine kinase inhibitor (TKI): TKI therapy group (including combination with chemotherapy), non-TKI therapy group (chemotherapy alone), and palliative care group.

RESULTS

More than half of the patients had higher levels of tumor biomarkers and the incidence of NSE was highest (81.8%), followed by CEA (74.4%) and Cyfra21-1 (74.1%). All patients had abnormal findings on chest computed tomography and with adenocarcinoma pathology. The overall survival (OS) time was 10.4 months in TKI group, 8.8 months in the non-TKI group, and 2.1 months in the palliative care group. Patients with higher level of serum Cyfra21-1 had insignificantly shorter survival time compared to those with normal Cyfra21-1 (p = 0.067). TKI therapy and non-TKI therapy provided a better prognosis prediction compared to palliative care. TKI therapy improved prognosis compared to non-TKI therapy. The comprehensive based TKI therapy provided improved OS vs the non-TKI therapy.

CONCLUSION

TKI-based therapy could improve the prognosis and OS for advanced P-ADC. This study recommends the analysis of EGFR mutations for all patients with advanced P-ADC.

Mucor pulmonary embolism in a patient with myelodysplastic syndrome

Mucormycosis is a life-threatening infectious disease that occurs most commonly in immunocompromised patients such as those with hematological malignancies. Its clinical symptoms and associated radiological findings vary and specific biomarkers and culture characteristics have not been defined. An 85-year-old man who had been treated for myelodysplastic syndrome and tuberculosis for several months presented with subacute fever and worsening left-side chest pain. Contrast-enhanced computed tomography images depicted massive tumor-like consolidation without enhancement, expanding from the left lower lobe. Emboli that did not respond to anticoagulants were detected in the left descending pulmonary artery. Despite intensive treatment he developed multiple organ failure and died 47 days after hospitalization. Gross pathology of a lung autopsy specimen revealed left lower pulmonary arterial emboli and pulmonary infarction, which was concluded to be the direct cause of death. The emboli were histopathologically identified as invasive mycelia in vessels. Mucor sp. was detected via real-time polymerase chain reaction and immunohistopathological analyses revealed that the mold in the blood vessels of lung tissue was partially positive for the mucor antigen. In the present case of Mucor sp. pulmonary emboli in a patient with myelodysplastic syndrome, radiographic findings were hard to distinguish from those typical of a lung abscess.

Bacterial pneumonia and its associated factors in children from a developing country: A prospective cohort study

Introduction

Pneumonia in children is a common disease yet determining its aetiology remains elusive.

Objectives

To determine the a) aetiology, b) factors associated with bacterial pneumonia and c) association between co-infections (bacteria + virus) and severity of disease, in children admitted with severe pneumonia.

Methods

A prospective cohort study involving children aged 1-month to 5-years admitted with very severe pneumonia, as per the WHO definition, over 2 years. Induced sputum and blood obtained within 24 hrs of admission were examined via PCR, immunofluorescence and culture to detect 17 bacteria/viruses. A designated radiologist read the chest radiographs.

Results

Three hundred patients with a mean (SD) age of 14 (±15) months old were recruited. Significant pathogens were detected in 62% of patients (n = 186). Viruses alone were detected in 23.7% (n = 71) with rhinovirus (31%), human metapneumovirus (HMP) [22.5%] and respiratory syncytial virus (RSV) [16.9%] being the commonest. Bacteria alone was detected in 25% (n = 75) with Haemophilus influenzae (29.3%), Staphylococcus aureus (24%) and Streptococcus pneumoniae (22.7%) being the commonest. Co-infections were seen in 13.3% (n = 40) of patients. Male gender (AdjOR 1.84 [95% CI 1.10, 3.05]) and presence of crepitations (AdjOR 2.27 [95% CI 1.12, 4.60]) were associated with bacterial infection. C-reactive protein (CRP) [p = 0.007]) was significantly higher in patients with co-infections but duration of hospitalization (p = 0.77) and requirement for supplemental respiratory support (p = 0.26) were not associated with co-infection.

Conclusions

Bacteria remain an important cause of very severe pneumonia in developing countries with one in four children admitted isolating bacteria alone. Male gender and presence of crepitations were significantly associated with bacterial aetiology. Co-infection was associated with a higher CRP but no other parameters of severe clinical illness.

Multiple cavitary lung lesions on CT: imaging findings to differentiate between malignant and benign etiologies

Objective:

To determine the CT findings of multiple cavitary lung lesions that allow the differentiation between benign and malignant etiologies.

Methods:

We reviewed CT scans, including patients with two or more cavitary lung lesions. We evaluated the number of cavitary lesions, their location, cavity wall thickness, and additional findings, correlating the variables with the diagnosis of a benign or malignant lesion.

Results:

We reviewed the chest CT scans of 102 patients, 58 (56.9%) of whom were male. The average age was 50.5 ± 18.0 years. Benign and malignant lesions were diagnosed in 74 (72.6%) and 28 (27.4%) of the patients, respectively. On the CT scans, the mean number of cavities was 3, the mean wall thickness of the largest lesions was 6.0 mm, and the mean diameter of the largest lesions was 27.0 mm. The lesions were predominantly in the upper lobes, especially on the right (in 43.1%). In our comparison of the variables studied, a diagnosis of malignancy was not found to correlate significantly with the wall thickness of the largest cavity, lymph node enlargement, emphysema, consolidation, bronchiectasis, or bronchial obstruction. The presence of centrilobular nodules correlated significantly with the absence of malignant disease (p < 0.05). In contrast, a greater number of cavities correlated significantly with malignancy (p < 0.026).

Conclusions:

A larger number of cavitary lung lesions and the absence of centrilobular nodules may be characteristic of a malignant etiology. However, on the basis of our evaluation of the lesions in our sample, we cannot state that wall thickness is a good indicator of a benign or malignant etiology.

A Malaysian ex-smoker with cough, breathlessness and nonresolving bronchospasm

Repeated noisy breathing may be a tricky feature of lung infection. Recognising classical features in radiographs and CT scans may help in the diagnosis of severe lung infection and the start of life-saving treatment. http://bit.ly/2lQwe5y.

Left destroyed lung caused by a pen cap in the left lower lobe bronchus "swallowed" 25 years ago

A delayed diagnosis of tracheobronchial foreign body aspiration (FBA) may result in severe respiratory complications such as pneumonia, bronchiectasis, and atelectasis. Here, we present a rare case of a left lung destruction caused by a pen cap that remained in the left lower lobe bronchus for 25 years and was previously misdiagnosed as cavitary tuberculosis. The foreign body was not detected in bronchoscopic examination prior to surgery due to severe stenosis of the left main bronchus. The foreign body was found incidentally while the patient was undergoing left pneumonectomy. To the best of our knowledge, this the second longest delay to diagnosis of FBA reported. This case also exemplifies the grave consequences of misdiagnosis of FBA.