"Crazy-paving" pattern at thin-section CT of the lungs: radiologic-pathologic overview

A solitary pulmonary nodule in a former glass blower mimicking a primary lung adenocarcinoma

INTRODUCTION

Inhalation of silicon dioxide causes silicosis, a condition that may occur in various industries and work settings. Radiologic findings typically show numerous nodular opacities, while solitary pulmonary nodules are atypical for silicosis.

PRESENTATION OF CASE

A 68-year-old woman, a former glassblower, presented with a left solitary pulmonary nodule (13 mm) on chest computed tomography. The nodule enlarged to 23 mm over 6 months, exhibiting an irregular shape, spiculated margin, and rapid growth with a doubling time of 186.4 days. She underwent a left upper lobectomy with a suspicion of lung cancer. The histopathological findings revealed peribronchial lymphocytic infiltration and granulomatous-like structures containing multinucleated giant cells and phagocytic crystalline foreign bodies. These findings were consistent with a foreign body reaction to the glass fragments.

DISCUSSION

Inhaled glass fragments may present as a solitary pulmonary nodule after the retirement of a glass blower. Its behavior and radiological features mimicked a primary lung adenocarcinoma.

CONCLUSION

Solitary pulmonary nodules due to inhaled glass fragments may mimic a primary lung adenocarcinoma. A definitive diagnosis requires a histological examination in this rare condition.

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.

Pulmonary Contusion-An Unusual Clinical and Radiological Presentation: Case Report

Pulmonary contusion (PC), defined as damage to the lung parenchyma with edema and hemorrhage, has classically been associated with acceleration-deceleration injuries. It is a frequent pathology in clinical practice. However, its clinical presentation and imaging findings are nonspecific. Patients with this entity can present with findings that can range from mild dyspnea to life-threatening respiratory failure and hemodynamic instability. We present the case of a 61-year-old man, a former smoker, who presented to the emergency department after suffering blunt chest trauma. On admission, he complained of only mild shortness of breath, and his vital signs were typical. Initial imaging identified asymmetric pulmonary infiltrates and mediastinal lymphadenopathy; this was suspicious for additional pathology in addition to PC. After an exhaustive evaluation, a neoplastic or infectious disease process was ruled out. Even though the patient presented with a clinical deterioration of respiratory function compatible with secondary acute respiratory distress syndrome, there was a complete recovery after supportive measures and supplemental oxygen. In conclusion, the nonspecific clinical and imaging findings in patients with pulmonary contusion warrant a complete evaluation of these cases. An early diagnosis is essential to establish adequate support and monitoring to prevent possible complications that could worsen the patient's prognosis.

[Congenital pulmonary alveolar proteinosis in a neonate]

The male patient was referred to the hospital at 44 days old due to dyspnea after birth and inability to wean off oxygen. His brother died three days after birth due to respiratory failure. The main symptoms observed were respiratory failure, dyspnea, and hypoxemia. A chest CT scan revealed characteristic reduced opacity in both lungs with a "crazy-paving" appearance. The bronchoalveolar lavage fluid (BALF) showed periodic acid-Schiff positive proteinaceous deposits. Genetic testing indicated a compound heterozygous mutation in the ABCA3 gene. The diagnosis for the infant was congenital pulmonary alveolar proteinosis (PAP). Congenital PAP is a significant cause of challenging-to-treat respiratory failure in full-term infants. Therefore, congenital PAP should be considered in infants experiencing persistently difficult-to-treat dyspnea shortly after birth. Early utilization of chest CT scans, BALF pathological examination, and genetic testing may aid in early diagnosis.

A 68-Year-Old Patient With Dyspnea and Hypoxemia After Total Hip Arthroplasty

CASE PRESENTATION

A 68-year-old patient with obesity (BMI, 4 7 kg/m2) was transferred to the ED of our hospital because of dyspnea and pronounced hypoxemia. The patient underwent total right hip arthroplasty in an outside hospital because of osteoarthritis; there was no history of trauma. After 48 h, she experienced dyspnea with severe hypoxemia. The next day she was transferred to our hospital. Her history was notable for arterial hypertension and depression, but not heart failure. Her medications included candesartan (16 mg once daily) and sertraline (100 mg once daily). Perioperatively, she received enoxaparin 4.000 International Units subcutaneously once daily. There was no family history of respiratory diseases. The patient currently smokes (50 pack-years) with no recent increase in her habit and denied vaping, alcohol consumption, illicit drug use, and any home or occupational exposures. Prior to surgery, the family of the patient reported that she maintained modest mobility despite her osteoarthritis and was able to fulfill her daily activities. Interestingly, she reported a similar event of severe dyspnea and hypoxemia after total knee arthroplasty 3 years earlier; however, no further details were available.

Stepwise progression of invasive mucinous adenocarcinoma based on radiological and biological characteristics

INTRODUCTION

Invasive mucinous lung adenocarcinoma (IMA) has unique radiological findings and pathological characteristics. IMA is classified into solitary and pneumonic types; however, it is unclear whether these are biologically identical.

METHODS

A single-center retrospective analysis was performed for 70 IMA patients (solitary type [n = 38] and pneumonic type [n = 32]) who underwent pulmonary resection between January 2010 and December 2018. We compared clinical and biological characteristics between the two types.

RESULTS

The frequencies of genetic alternations such as EGFR, KRAS, BRAF, GNAS, ERBB2, TP53, NRG1, and MET were not different. Immunohistochemically, expression of MUC1 was significantly more common in the pneumonic type (5.0% versus 20.0%, p = 0.01) and diffuse MUC6 positive in the solitary type (39.0% versus 13.0%, p = 0.02). We further classified solitary types into those with or without ground-glass opacity (GGO) and pneumonic types into those with or without crazy-paving appearance (CPA), and evaluated their surgical outcomes. Five-year overall survival and relapse free survival rates were 95.8%/86.6%, 64.3%/70.7%, 74.6%/68.9%, and 50.0%/28.6% in patients with solitary type with GGO, solitary type without GGO, pneumonic type without CPA, and pneumonic type with CPA, respectively.

CONCLUSIONS

There were no differences in genetic alternations; however, mucin expression pattern was different. Surgical outcomes were different according to the presence of GGO in the solitary type and the presence of CPA in the pneumonic type. These findings suggested a stepwise progression from solitary to pneumonic IMA.

Milani A, Madani Tonekaboni SA, Rabbani H, Hekmatnia A, Kafieh R. Biased Deep Learning Methods in Detection of COVID-19 Using CT Images: A Challenge Mounted by Subject-Wise-Split ISFCT Dataset

Accurate detection of respiratory system damage including COVID-19 is considered one of the crucial applications of deep learning (DL) models using CT images. However, the main shortcoming of the published works has been unreliable reported accuracy and the lack of repeatability with new datasets, mainly due to slice-wise splits of the data, creating dependency between training and test sets due to shared data across the sets. We introduce a new dataset of CT images (ISFCT Dataset) with labels indicating the subject-wise split to train and test our DL algorithms in an unbiased manner. We also use this dataset to validate the real performance of the published works in a subject-wise data split. Another key feature provides more specific labels (eight characteristic lung features) rather than being limited to COVID-19 and healthy labels. We show that the reported high accuracy of the existing models on current slice-wise splits is not repeatable for subject-wise splits, and distribution differences between data splits are demonstrated using t-distribution stochastic neighbor embedding. We indicate that, by examining subject-wise data splitting, less complicated models show competitive results compared to the exiting complicated models, demonstrating that complex models do not necessarily generate accurate and repeatable results.

Fat Pulmonary Embolism With Crazy-Paving Pattern Opacities and Pneumothorax: A Rare Complication of Liposuction

Fat embolism syndrome (FES) is a rare multiorgan disease caused by microvascular obstruction by fat globules and free fatty acid-mediated endothelial injury leading to pro-inflammatory cytokine release. We present a rare case of a 54-year-old woman who underwent elective aesthetic liposuction and developed FES and pneumothorax within 12 hours of the procedure.

An Internist's Approach to a Case of Negative Pressure Pulmonary Edema: A Rare Cause of Noncardiogenic Pulmonary Edema

Negative-pressure pulmonary edema (NPPE) is a rare cause of noncardiogenic pulmonary edema, which usually presents postoperatively. Its pathophysiology is mostly described as a profound negative intrathoracic pressure caused by an airway obstruction such as laryngospasm, which may occur during extubation. But, there are other hypotheses about it, such as catecholamines release causing an elevated hydrostatic pressure in the cardiopulmonary circuit and, consequently, a major capillary leak to the interstitium. Its natural course varies, from prompt recovery to intensive care unit escalation and prolonged mechanical ventilation. Although anesthesiologists often detect this condition, this case's objective is to bring awareness of this condition to internists as a potential differential diagnosis for hypoxia in the postoperative setting.

Pulmonary computed tomographic manifestations of COVID-19 in vaccinated and non-vaccinated patients

This study aimed to analyze computed tomographic (CT) imaging features of vaccinated and non-vaccinated COVID-19 patients. The study population of this retrospective single-center cohort study consisted of hospitalized COVID-19 patients who received a chest CT at the study site between July 2021 and February 2022. Qualitative scoring systems (RSNA, CO-RADS, COV-RADS), imaging pattern analysis and semi-quantitative scoring of lung changes were assessed. 105 patients (70,47% male, 62.1 ± 16.79 years, 53.3% fully vaccinated) were included in the data analysis. A significant association between vaccination status and the presence of the crazy-paving pattern was observed in univariate analysis and persisted after step-wise adjustment for possible confounders in multivariate analysis (RR: 2.19, 95% CI: [1.23, 2.62], P = 0.024). Scoring systems for probability assessment of the presence of COVID-19 infection showed a significant correlation with the vaccination status in univariate analysis; however, the associations were attenuated after adjustment for virus variant and stage of infection. Semi-quantitative assessment of lung changes due to COVID-19 infection revealed no association with vaccination status. Non-vaccinated patients showed a two-fold higher probability of the crazy-paving pattern compared to vaccinated patients. COVID-19 variants could have a significant impact on the CT-graphic appearance of COVID-19.

A review of organizing pneumonia

ABSTRACT

Organizing pneumonia is a clinical and pathological syndrome that describes a lung injury caused by an inflammatory reaction in the alveolar connective tissue. Classified as an interstitial lung disease, it can be secondary to infection, drug toxicity, connective tissue disorders, inhalation injuries (cocaine), organ transplant, or radiotherapy, and also can be idiopathic. Although organizing pneumonia is not a new phenomenon, it has been noted to be a complication of COVID-19, and should be considered in patients who have had COVID-19 and have atypical chest imaging, because treatment includes corticosteroids instead of antimicrobials.

Postoperative hypoxaemic acute respiratory failure after neoadjuvant treatment for lung cancer: radiologic findings and risk factors

OBJECTIVES

To investigate the rate of hypoxaemic acute respiratory failure (hARF) on patients undergoing surgery for non-small-cell lung cancer (NSCLC) after neoadjuvant chemotherapy, to describe clinical and radiological findings and to explore potential risk factors for this complication.

METHODS

Retrospective review of medical records of all patients who underwent surgery for NSCLC after neoadjuvant chemotherapy at a single centre between 2014 and 2021. Computed tomography scans of patients who developed hARF were reviewed by an experienced radiologist to provide a quantitative assessment of radiologic alterations.

RESULTS

The final cohort consisted of 211 patients. Major morbidity was 13.3% (28/211) and hARF was the most common major complication (n = 11, 5.2%). Postoperative mortality was 1.9% (4/211) and occurred only in patients who experienced hARF. Most patients who experienced hARF underwent major procedures, including pneumonectomy (n = 3), lobectomy with chest wall resection (n = 3), bronchial or vascular reconstructions (n = 3) and extended or bilateral resections (n = 2). Analysis of computed tomography findings revealed that crazy paving and ground glass were the most common alterations and were more represented in the non-operated lung. Male gender, current smoking status, pathologic stage III-IV and operative time resulted significant risk factors for hARF at univariable analysis (P < 0.05).

CONCLUSIONS

hARF is the main cause of major morbidity and mortality after neoadjuvant therapy and surgery for NSCLC and occurs more frequently after complex and lengthier surgical procedures. Overall, our findings suggest that operative time may represent the most important risk factor for hARF.

Organizing pneumonia

Organizing pneumonia is a nonspecific pathologic pattern of response to lung damage. It can be idiopathic, or it can occur secondary to various medical processes, most commonly infections, connective tissue disease, and pharmacological toxicity. Although there is no strict definition of the pattern of organising pneumonia as in other idiopathic interstitial pneumonias, the characteristic pattern of this disease could be considered to include patchy consolidations and ground-glass opacities in the peribronchial and subpleural areas of both lungs. Moreover, studies of the course of the disease show that these lesions respond to treatment with corticoids, migrate with or without treatment, and tend to recur when treatment is decreased or withdrawn. Other manifestations of organising pneumonia include nodules of different sizes and shapes, solitary masses, nodules with the reverse halo sign, a perilobular pattern, and parenchymal bands.

High-Resolution Computed Tomography of Nonfibrotic Interstitial Lung Disease

Nonfibrotic interstitial lung diseases include a heterogeneous group of conditions that can result in various patterns of lung involvement. When approaching the computed tomographic (CT) scan of a patient with a suspected or known interstitial lung disease, the use of the appropriate radiological terms and a systematic, structured approach to the interpretation of the imaging findings are essential to reach a confident diagnosis or to limit the list of differentials to few possibilities. The large number of conditions that cause nonfibrotic interstitial lung diseases prevents a thorough discussion of all these entities. Therefore, this article will focus on the most common chronic lung diseases that can cause these CT findings. A pattern-based approach is used, with a discussion of nodular pattern, consolidation, crazy paving, ground-glass opacities, septal thickening, and calcifications. The different clinical conditions will be described based on their predominant pattern, with particular attention to findings that can help in the differential diagnosis.

Unilateral Autoimmune Pulmonary Alveolar Proteinosis with Polymyositis-related Interstitial Lung Disease

A 61-year-old patient with cystic bronchiectasis and bronchial artery hyperplasia in the left lung was diagnosed with polymyositis-related interstitial lung disease. After nine months of immunosuppressive therapy, he developed unilateral autoimmune pulmonary alveolar proteinosis (APAP) in the right lung with respiratory failure. After bronchial artery embolization to prevent massive hemoptysis, whole-lung lavage was performed using veno-venous extracorporeal membrane oxygenation. His respiratory condition improved, and he was discharged from the hospital with supplemental oxygen. Three reported cases of APAP with polymyositis-related interstitial lung disease, including the present case, were all positive for anti-glycyl tRNA synthetase antibody and were under immunosuppressive treatment.

Enhancing Imagistic Interstitial Lung Disease Diagnosis by Using Complex Networks

Background and Objectives: Diffuse interstitial lung diseases (DILD) are a heterogeneous group of over 200 entities, some with dramatical evolution and poor prognostic. Because of their overlapping clinical, physiopathological and imagistic nature, successful management requires early detection and proper progression evaluation. This paper tests a complex networks (CN) algorithm for imagistic aided diagnosis fitness for the possibility of achieving relevant and novel DILD management data. Materials and Methods: 65 DILD and 31 normal high resolution computer tomography (HRCT) scans were selected and analyzed with the CN model. Results: The algorithm is showcased in two case reports and then statistical analysis on the entire lot shows that a CN algorithm quantifies progression evaluation with a very fine accuracy, surpassing functional parameters' variations. The CN algorithm can also be successfully used for early detection, mainly on the ground glass opacity Hounsfield Units band of the scan. Conclusions: A CN based computer aided diagnosis could provide the much-required data needed to successfully manage DILDs.

A 44-year-old stone worker with progressive dyspnea: lessons from a new twist on an old foe

Silicosis is typically an indolent lung disease caused by long-standing occupational exposure to respirable crystalline silica, classically in professions such as sandblasting and mining.  An increasingly popular industry that has earned particular interest because of its association with silicosis is customization and installation of artificial stone countertops for domestic applications. In addition to causing a spike in cases of chronic and accelerated silicosis, both quite familiar to respiratory clinicians, outbreaks of artificial stone silicosis have brought to the fore a historically rare entity known as acute silicosis, or silicoproteinosis, a more rapid presentation of the disease. Failure to suspect this uncommon condition can lead to diagnostic confusion and therefore ineffective treatment as was true initially of the patient we describe herein.  The case description is followed by a clinical, radiological, and pathological overview of acute artificial stone silicosis (or silicoproteinosis), which is an emerging pneumoconiosis with sparse coverage in the literature to date.  This case also adds to the few existing reports on the use of therapeutic whole lung lavage for silicoproteinosis.      

Algorithmic Approach to the Diagnosis of Organizing Pneumonia: A Correlation of Clinical, Radiologic, and Pathologic Features

Organizing pneumonia (OP), characterized histopathologically by patchy filling of alveoli and bronchioles by loose plugs of connective tissue, may be seen in a variety of conditions. These include but are not limited to after an infection, drug reactions, radiation therapy, and collagen vascular diseases. When a specific cause is responsible for this entity, it is referred to as "secondary OP." When an extensive search fails to reveal a cause, it is referred to as "cryptogenic OP" (previously called "bronchiolitis obliterans with OP"), which is a clinical, radiologic, and pathologic entity classified as an interstitial lung disease. The clinical presentation of OP often mimics that of other disorders, such as infection and cancer, which can result in a delay in diagnosis and inappropriate management of the underlying disease. The radiographic presentation of OP is polymorphous but often has subpleural consolidations with air bronchograms or solitary or multiple nodules, which can wax and wane. Diagnosis of OP sometimes requires histopathologic confirmation and exclusion of other possible causes. Treatment usually requires a prolonged steroid course, and disease relapse is common. The aim of this article is to summarize the clinical, radiographic, and histologic presentations of this disease and to provide a practical diagnostic algorithmic approach incorporating clinical history and characteristic imaging patterns.

Radiological Finding of Crazy-Paving Pattern in COVID-19 Pneumonia

The recent global pandemic of coronavirus disease 2019 (COVID-19) has brought many radiographic findings in other respiratory disease processes. One of these radiological findings is crazy paving. This paper discusses crazy paving in a 75-year-old female with dyspnea, nonproductive cough, pleuritic chest pain, and a polymerase chain reaction (PCR) positive test for COVID-19 infection. Chest CT showed ground-glass opacities and interlobular septal thickening consistent with a crazy-paving appearance. As part of the common CT findings of patients with active COVID-19 infection, crazy paving should prompt the interpreting radiologist to consider COVID-19 pneumonia as part of the differential.

COVID-19 and H1N1-09: A Systematic Review of Two Pandemics with a Focus on the Lung at Autopsy

BACKGROUND

The purpose of this manuscript is to provide a comparative overview of the two global pandemics: the first on June 11th 2009 due to influenza A H1N1 (H1N1-09); the second and current pandemic caused by coronavirus 2019 (COVID-19) on March 11th 2020, focusing on how autopsy can contribute to the definition of cellular pathology, to clinical pathology and, more generally, to public health.

METHODS

A systematic literature search selection was conducted on PubMed database on June 5, 2021, with this search strategy: (COVID-19) AND (H1N1 influenza) showing 101 results. The following inclusion criteria were selected: English language; published in a scholarly peer-reviewed journal; full-length articles were further elected. To further refine the research was to focus on the type of manuscript: review, systematic review, and meta-analysis. A critical appraisal of the collected studies was conducted, analyzing titles and abstracts, excluding the following topics: treatment, public health measures and perception of the general population or healthcare personnel about their quality of life. According to these procedures, 54 eligible studies were included in the present review.

RESULTS

Histopathological findings play a key role in understanding the pathophysiological mechanisms of diseases and, thus possible therapeutic approaches. The evidence on the thrombo-inflammatory mechanism underlying COVID-19 is growing to a much greater magnitude than the diffuse alveolar damage in common with H1N1-09; our study appears to be in line with these results. The prevailing scientific thinking to explain the morbidity and mortality of COVID-19 patients is that it elicits an exuberant immune reaction characterized by dysregulated cytokine production, known as a "cytokine storm".

CONCLUSIONS

The histological and immunohistochemical pattern demonstrated similarities and differences between the infectious manifestations of the two pathogens, which justify empirical therapeutic approaches, in the first phase of the COVID-19 pandemic. Therefore, the previous pandemic should have taught us to promote a culture of clinical and forensic autopsies in order to provide timely evidence from integration among autopsy and clinical data for early adopting adequate therapies.

COVID-19 in Italy: Comparison of CT Findings from Time Zero to the Delta Variant

On 12 March 2020, the World Health Organization (WHO) declared the novel Coronavirus (CoV) disease a global Pandemic and an emerging risk. In order to understand patterns that are typical in COVID-19 pneumonia and track the evolution of the disease, the role of the chest computed tomography (CT) is pivotal. The impact of the illness as well as the efficiency of the therapy are also monitored carefully when performing this imaging exam. Coronaviruses, specifically CoV-2, as RNA viruses, have a tendency to frequently change their genome, giving the virus beneficial characteristics such as greater transmissibility, pathogenicity and the possibility to escape the previously acquired immunity. Therefore, genome evaluation became an extremely important routine practice worldwide. In particular, in Italy, four variants have been recognised and each of them represent a specific temporal wave of the disease. Hence, our goal was to describe imaging findings of COVID-19 pneumonia, specifically its most typical imaging identified during the period of our study, and to assess whether or not SARS-CoV-2 variants determine different CT patterns. Our analyses revealed that the SARS-CoV-2 genotype seems not to interfere with the severity of CT patterns and, in particular, bilateral Ground Glass Opacities (GGOs) are the most frequent findings in all COVID-19 waves.

ERRATUM

[This corrects the article doi: 10.36416/1806-3756/e20200595].

Consensus statement on thoracic radiology terminology in Portuguese used in Brazil and in Portugal

Effective communication among members of medical teams is an important factor for early and appropriate diagnosis. The terminology used in radiology reports appears in this context as an important link between radiologists and other members of the medical team. Therefore, heterogeneity in the use of terms in reports is an important but little discussed issue. This article is the result of an extensive review of nomenclature in thoracic radiology, including for the first time terms used in X-rays, CT, and MRI, conducted by radiologists from Brazil and Portugal. The objective of this review of medical terminology was to create a standardized language for medical professionals and multidisciplinary teams.

Radiomics-based machine learning differentiates "ground-glass" opacities due to COVID-19 from acute non-COVID-19 lung disease

Ground-glass opacities (GGOs) are a non-specific high-resolution computed tomography (HRCT) finding tipically observed in early Coronavirus disesase 19 (COVID-19) pneumonia. However, GGOs are also seen in other acute lung diseases, thus making challenging the differential diagnosis. To this aim, we investigated the performance of a radiomics-based machine learning method to discriminate GGOs due to COVID-19 from those due to other acute lung diseases. Two sets of patients were included: a first set of 28 patients (COVID) diagnosed with COVID-19 infection confirmed by real-time polymerase chain reaction (RT-PCR) between March and April 2020 having (a) baseline HRCT at hospital admission and (b) predominant GGOs pattern on HRCT; a second set of 30 patients (nCOVID) showing (a) predominant GGOs pattern on HRCT performed between August 2019 and April 2020 and (b) availability of final diagnosis. Two readers independently segmented GGOs on HRCTs using a semi-automated approach, and radiomics features were extracted using a standard open source software (PyRadiomics). Partial least square (PLS) regression was used as the multivariate machine-learning algorithm. A leave-one-out nested cross-validation was implemented. PLS β-weights of radiomics features, including the 5% features with the largest β-weights in magnitude (top 5%), were obtained. The diagnostic performance of the radiomics model was assessed through receiver operating characteristic (ROC) analysis. The Youden's test assessed sensitivity and specificity of the classification. A null hypothesis probability threshold of 5% was chosen (p < 0.05). The predictive model delivered an AUC of 0.868 (Youden's index = 0.68, sensitivity = 93%, specificity 75%, p = 4.2 × 10-7). Of the seven features included in the top 5% features, five were texture-related. A radiomics-based machine learning signature showed the potential to accurately differentiate GGOs due to COVID-19 pneumonia from those due to other acute lung diseases. Most of the discriminant radiomics features were texture-related. This approach may assist clinician to adopt the appropriate management early, while improving the triage of patients.

Therapeutic and diagnostic targeting of fibrosis in metabolic, proliferative and viral disorders

Fibrosis is a common denominator in many pathologies and crucially affects disease progression, drug delivery efficiency and therapy outcome. We here summarize therapeutic and diagnostic strategies for fibrosis targeting in atherosclerosis and cardiac disease, cancer, diabetes, liver diseases and viral infections. We address various anti-fibrotic targets, ranging from cells and genes to metabolites and proteins, primarily focusing on fibrosis-promoting features that are conserved among the different diseases. We discuss how anti-fibrotic therapies have progressed over the years, and how nanomedicine formulations can potentiate anti-fibrotic treatment efficacy. From a diagnostic point of view, we discuss how medical imaging can be employed to facilitate the diagnosis, staging and treatment monitoring of fibrotic disorders. Altogether, this comprehensive overview serves as a basis for developing individualized and improved treatment strategies for patients suffering from fibrosis-associated pathologies.

Role of Chest CT in COVID-19

In December 2019, a disease attributed to a new severe acute respiratory syndrome coronavirus 2, and named coronavirus disease 2019 (COVID-19), broke out in Wuhan, China and has spread rapidly throughout the world. CT has been advocated in selected indications as a tool toward rapid and early diagnosis. The CT patterns of COVID-19 include ground glass opacities GGO, consolidation, and crazy paving. Additional signs include a “rounded morphology” of lesions, vascular enlargement sign, nodules, and fibrous stripe. Signs of healing and organization include subpleural bands, a reticular pattern, reversed halo sign and traction bronchiectasis. Cavitation and tree in bud signs are absent and pleural effusions are rare. There is a high incidence of pulmonary embolism associated with COVID-19. CT findings in COVID-19 appear to follow a predictable timeline with maximal involvement approximately 6–11 days after symptom onset. The stages of evolution include early stage (days 0–4) with GGO being the predominant abnormality, progressive stage (days 5–8) with increasing crazy paving; and peak stage (days 9–13) with predominance of consolidation and absorption phase (after day 14) with gradual absorption of consolidation with residual GGO and subpleural bands. CT findings in COVID-19 have a high sensitivity and low specificity, determined to be 98% and 25% in a retrospective study of 1014 patients. The low specificity of CT for the diagnosis of COVID-19 pneumonia is due to the overlap of CT findings with other viral pneumonias and other infections, lung involvement in connective tissue disorders, drug reaction, pulmonary edema, and hemorrhage.

Ultra-low-dose chest CT performance for the detection of viral pneumonia patterns during the COVID-19 outbreak period: a monocentric experience

Background

Ultra low dose chest computed tomography (CT) acquisitions have been used for selected emergency room patients with acute dyspnea or minor thoracic trauma. The purpose of this study was to evaluate the diagnostic performance of ultra-low-dose (ULD) chest CT for detecting viral pneumonia patterns compared to standard (STD) dose chest CT.

Methods

All consecutive adult patients with two non-enhanced chest CT acquisitions, one STD and one ULD, for suspicion of viral pneumonia between March 5^th and April 2^nd 2020 were included. CT results were divided into two groups: non-viral pneumonia CT or compatible with viral pneumonia CT based on viral pneumonia CT patterns: ground-glass opacity (GGO), consolidation, crazy paving, air bronchogram signs and fibrous stripes. The diagnostic performance of ULD CT for suspicion of viral pneumonia was evaluated. For CTs compatible with viral pneumonia, CT pattern detection on ULD CT was assessed and STD CT was used as a reference.

Results

The study included 380 patients with 97 CTs (25.5%) compatible with viral pneumonia. The mean effective doses (EDs) were 1.66 (1.29; 2.18) mSv for STD and 0.20 (0.18; 0.22) mSv for ULD CT (P<0.001). The sensitivity and specificity of ULD CT for viral pneumonia detection were 98.9% and 99.0%, respectively. GGO, consolidation and fibrous stripes were equally visible in STD and ULD in 100% (n=97), 36% (n=35) and 23% (n=22) of compatible viral pneumonia-CT patients, respectively. Air bronchogram sign detection was equivalent, concerning 23% (n=22) of patients in STD and 22% (n=21) in ULD. Crazy paving was visible in 24% (n=23) of patients in STD and only 8% (n=8) in ULD (P=0.003).

Conclusions

In comparison to STD dose chest CT, ULD chest CT, with a mean reduction dose of 88.0%, has comparable diagnostic performance for detecting viral pneumonia on CT.

Pulmonary alveolar proteinosis complicated with tuberculosis: A case report

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by the accumulation of phospholipoproteinaceous material in the alveoli. Cases of PAP complicated with tuberculosis are much more complex and have rarely been well recorded.

CASE SUMMARY

We describe a 21-year-old Han Chinese patient with suspicious lung infection associated with mild restrictive ventilatory dysfunction and diffusion reduction. High resolution computed tomography revealed a “crazy-paving” appearance and multiple pulmonary miliary nodules around the bronchi. Bronchoalveolar lavage demonstrated a small amount of periodic acid-Schiff positive proteinaceous materials. A serological test for the presence of a Mycobacterium tuberculosis antibody and an interferon-gamma release assay were both positive. The patient received a standard course of first-line anti-tuberculosis treatment after diagnostic bronchoalveolar lavage. To date, clinical remission has been achieved and maintained for five years.

CONCLUSION

In summary, the diagnosis of PAP complicated with tuberculosis was supported by a combination of clinical manifestations, imaging, pulmonary function, laboratory examinations, bronchoalveolar lavage, etc. This case highlighted that diagnostic bronchoalveolar lavage in combination with anti-tuberculosis treatment is a safe and effective option for mild PAP patients with tuberculosis.

Simultaneous presence of the "bullseye" and "reversed halo" sign at CT of COVID-19 pneumonia: A case report

The "bullseye" sign has been exclusively reported in patients suffering from coronavirus disease 2019 (COVID-19) pneumonia. It is theorized that this newly recognized computed tomography (CT) feature represents a sign of organizing pneumonia. Well established signs of organizing pneumonia also reported in COVID-19 patients include linear opacities, the "reversed halo" sign (or "atoll" sign), and a perilobular distribution of abnormalities. These findings are usually present on imaging in the intermediate and late stage of the disease. This is a case of simultaneous presence of the "bullseye" and the "reversed halo" sign on chest CT images of a COVID-19 patient examined 22 days after symptom onset.

CT for Evaluation of Hemoptysis

Hemoptysis, which is defined as expectoration of blood from the alveoli or airways of the lower respiratory tract, is an alarming clinical symptom with an extensive differential diagnosis. CT has emerged as an important noninvasive tool in the evaluation of patients with hemoptysis, and the authors present a systematic but flexible approach to CT interpretation. The first step in this approach involves identifying findings of parenchymal and airway hemorrhage. The second step is aimed at determining the mechanism of hemoptysis and whether a specific vascular supply can be implicated. Hemoptysis can have primary vascular and secondary vascular causes. Primary vascular mechanisms include chronic systemic vascular hypertrophy, focally damaged vessels, a dysplastic lung parenchyma with systemic arterial supply, arteriovenous malformations and fistulas, and bleeding at the capillary level. Evaluating vascular mechanisms of hemoptysis at CT also entails determining if a specific vascular source can be implicated. Although the bronchial arteries are responsible for most cases of hemoptysis, nonbronchial systemic arteries and the pulmonary arteries are important potential sources of hemoptysis that must be recognized. Secondary vascular mechanisms of hemoptysis include processes that directly destroy the lung parenchyma and processes that directly invade the airway. Understanding and employing this approach allow the diagnostic radiologist to interpret CT examinations accurately in patients with hemoptysis and provide information that is best suited to directing subsequent treatment. ^©RSNA, 2021.

Prognostic impact of early adjunctive corticosteroid therapy in non-HIV oncology or haematology patients with Pneumocystis jirovecii pneumonia: A propensity score analysis

Purpose

While early adjunctive corticosteroid therapy (EACST) has been proven effective in HIV patients with Pneumocystis Jirovecii Pneumonia (PJP), data remains controversial concerning non-HIV oncology or haematology patients.

Methods

This retrospective study included cancer patients without HIV and with diagnosis of PJP admitted in a cancer referral centre, from January-1-2010 to March-31-2017. We compared 30-day and 1-year mortality rate, change in the respiratory item of the Sequential Organ Failure Assessment score(SOFA-_resp worsening), use of tracheal intubation between day-1 and day-5 of anti-pneumocystis therapy and occurrence of coinfections between patients with EACST and those with no or late corticosteroid therapy, using an inverse probability weighting propensity score-based (IPW) analysis.

Results

133 non-HIV oncology or haematology PJP patients were included (EACST n = 58, others n = 75). The main underlying conditions were haematological malignancies (n = 107, 80,5%), solid tumour (n = 27, 20,3%) and allogeneic stem cell transplantation (n = 17, 12,8%). Overall 30-day and 1-year mortality rate was 24,1% and 56,4%, respectively. IPW analysis found no difference on 30-day (HR = 1.45, 95% CI [0.7–3.04], p = 0.321) and 1-year (HR = 1.25, CI 95% [0.75–2.09], p = 0.39) mortality rate between groups.

Conclusion

No difference in SOFA-_resp worsening, tracheal intubation and coinfections was found between groups. Combination of EACST with anti-pneumocystis therapy in non-HIV onco-haematology PJP-patients was not associated with clinical improvement.

Mild dyspnea presenting as 'crazy-paving' on chest computed tomography

Pulmonary alveolar proteinoisis (PAP) is a rare disease characterized by accumulation of proteinaceous material in the alveolar spaces. Here, we report a case of mild dyspnea with incidental ‘crazy-paving’ pattern on chest computed tomography (CT). Further evaluation and bronchoscopy found to have PAP.

Crazy-paving patterns as rare radiological manifestations of pulmonary cryptococcosis: a case report

Background

Crazy-paving patterns are rarely reported as radiological manifestations of pulmonary cryptococcosis.

Case presentation

Herein, we presented a very rare case of a crazy-paving pattern as a radiological manifestation of pulmonary cryptococcosis in a patient with primary ciliary dyskinesia. The diagnosis of pulmonary cryptococcosis and primary ciliary dyskinesia was ultimately confirmed by bronchoscopic biopsy, fungus culture, whole exome sequencing of blood, etc. The patient received flucytosine (PO, 5 g per day) and amphotericin B (IV, 70 mg per day) during hospitalization and sequential therapy with voriconazole (PO, 200 mg twice a day) after discharge. He recovered during follow-up.

Conclusions

We concluded that pulmonary cryptococcosis should be considered a possible cause of crazy-paving patterns in chest CT scans.

When pneumonia is not COVID-19

During the COVID-19 epidemic, the prevalence of the disease means that practically any lung opacity on an X-ray could represent pneumonia due to infection with SARS-CoV-2. Nevertheless, atypical radiologic findings add weight to negative microbiological or serological tests. Likewise, outside the epidemic wave and with the return of other respiratory diseases, radiologists can play an important role in decision making about diagnoses, treatment, or preventive measures (isolation), provided they know the key findings for entities that can simulate COVID-19 pneumonia. Unifocal opacities or opacities located in upper lung fields and predominant airway involvement, in addition to other key radiologic and clinical findings detailed in this paper, make it necessary to widen the spectrum of possible diagnoses.

When pneumonia is not COVID-19

During the COVID-19 epidemic, the prevalence of the disease means that practically any lung opacity on an X-ray could represent pneumonia due to infection with SARS-CoV-2. Nevertheless, atypical radiologic findings add weight to negative microbiological or serological tests. Likewise, outside the epidemic wave and with the return of other respiratory diseases, radiologists can play an important role in decision making about diagnoses, treatment, or preventive measures (isolation), provided they know the key findings for entities that can simulate COVID-19 pneumonia. Unifocal opacities or opacities located in upper lung fields and predominant airway involvement, in addition to other key radiologic and clinical findings detailed in this paper, make it necessary to widen the spectrum of possible diagnoses.

Evaluation of pulmonary ventilation in COVID-19 patients using oxygen-enhanced three-dimensional ultrashort echo time MRI: a preliminary study

AIM

To evaluate the lung function of coronavirus disease 2019 (COVID-19) patients using oxygen-enhanced (OE) ultrashort echo time (UTE) MRI.

MATERIALS AND METHODS

Forty-nine patients with COVID-19 were included in the study. The OE-MRI was based on a respiratory-gated three-dimensional (3D) radial UTE sequence. For each patient, the percent signal enhancement (PSE) map was calculated using the expression PSE = (S_100% – S_21%)/S_21%, where S_21% and S_100% are signals acquired during room air and 100% oxygen inhalation, respectively. Agreement of lesion detectability between UTE-MRI and computed tomography (CT) was performed using the kappa test. The Mann–Whitney U-test was used to evaluate the difference in the mean PSE between mild-type COVID-19 and common-type COVID-19. Spearman's test was used to assess the relationship between lesion mean PSE and lesion size. Furthermore, the Mann–Whitney U-test was used to evaluate the difference in region of interest (ROI) mean PSE between normal pulmonary parenchyma and lesions. The Kruskal–Wallis test was applied to test the difference in the mean PSE between different lesion types.

RESULTS

CT and UTE-MRI reached good agreement in lesion detectability. Ventilation measures in mild-type patients (5.3 ± 5.5%) were significantly different from those in common-type patients (3 ± 3.9%). Besides, there was no significant correlation between lesion mean PSE and lesion size. The mean PSE of COVID-19 lesions (3.2 ± 4.9%) was significantly lower than that of the pulmonary parenchyma (5.4 ± 3.9%). No significant difference was found among different lesion types.

CONCLUSION

OE-UTE-MRI could serve as a promising method for the assessment of lung function or treatment management of COVID-19 patients.

Predictors of Intensive Care Unit Admission among Hospitalized COVID-19 Patients in a Large University Hospital in Tehran, Iran

Background: The rapid increase in the spread of COVID-19 and the numbers of infected patients worldwide has highlighted the need for intensive care unit (ICU) beds and more advanced therapy. This need is more urgent in resource-constrained settings. The present study aimed to identify the predictors of ICU admission among hospitalized COVID-19 patients.

Study design: The current study was conducted based on a retrospective cohort design.

Methods: The participants included 665 definite cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) hospitalized in Imam Hossein Hospital from February 20 to May 14, 2020. The baseline characteristics of patients were assessed, and multivariate logistic regression analysis was utilized to determine the significant odds ratio (OR) for ICU admission.

Results: Participants were aged 59.52±16.72 years, and the majority (55.6%) of them were male. Compared to non-ICU patients (n=547), the ICU patients (n=118) were older, had more baseline comorbidities, and presented more often with dyspnea, convulsion, loss of consciousness, tachycardia, tachypnea, and hypoxia, and less often with myalgia. Significant OR (95% CI) of ICU admission was observed for the 60-80 age group (2.42, 95%CI: 1.01; 5.79), ≥80 age group (3.73, 95%CI: 1.44; 9.42), ≥3 comorbidities (2.07, 95%CI: 1.31; 3.80), loss of consciousness (6.70, 95%CI: 2.94, 15.24), tachypnea (1.79, 95%CI: 1.03, 3.11), and SpO2<90 (5.83, 95%CI: 2.74; 12.4). Abnormal laboratory results were more common among ICU-admitted patients; in this regard, leukocytosis (4.45, 95%CI: 1.49, 13.31), lymphopenia (2.39, 95%CI: 1.30; 4.39), elevated creatine phosphokinase (CPK) (1.99, 95%CI: 1.04; 3.83), and increased aspartate aminotransferase (AST) (2.25, 95%CI: 1.18-4.30) had a significant OR of ICU admission. Chest computer tomography (CT) revealed that consolidation (1.82, 95%CI: 1.02, 3.24), pleural effusion (3.19, 95%CI: 1.71, 5.95), and crazy paving pattern (8.36, 95%CI: 1.92, 36.48) had a significant OR of ICU admission.

Conclusion: As evidenced by the obtained results, the predictors of ICU admission were identified among epidemiological characteristics, presenting symptoms and signs, laboratory tests, and chest CT findings.

Chest Imaging in the Diagnosis of Occupational Lung Diseases

Imaging plays a crucial role in the diagnosis and monitoring of occupational lung diseases (OLDs); however, the sensitivity and specificity of detection and diagnosis vary greatly depending on the imaging modality used. There is substantial overlap in appearance with non-occupation-related entities. OLDs should be considered in the differential even in the absence of a provided exposure history. Because many findings are not specific, a multidisciplinary approach is important in arriving at the diagnosis and will continue to be important as workplace-related pulmonary diseases evolve with changing industrial practices and workplace regulations.

Chest Imaging of Patients with Sarcoidosis and SARS-CoV-2 Infection. Current Evidence and Clinical Perspectives

The recent COVID-19 pandemic has dramatically changed the world in the last months, leading to a serious global emergency related to a novel coronavirus infection that affects both sexes of all ages ubiquitously. Advanced age, cardiovascular comorbidity, and viral load have been hypothesized as some of the risk factors for severity, but their role in patients affected with other diseases, in particular immune disorders, such as sarcoidosis, and the specific interaction between these two diseases remains unclear. The two conditions might share similar imaging findings but have distinctive features that are here described. The recent development of complex imaging softwares, called deep learning techniques, opens new scenarios for the diagnosis and management.

The Significance of Subpleural Sparing in CT Chest: A State-of-the-Art Review

The subpleural sparing pattern is a common finding on computed tomography (CT) of the lungs. It comprises of pulmonary opacities sparing the lung peripheries, typically 1cm and less from the pleural surface. This finding has a variety of causes, including idiopathic, inflammatory, infectious, inhalational, cardiac, traumatic, and bleeding disorders. Specific disorders that can cause subpleural sparing patterns include nonspecific interstitial pneumonia (NSIP), organizing pneumonia (OP), pulmonary alveolar proteinosis (PAP), diffuse alveolar hemorrhage (DAH), vaping-associated lung injury (VALI), cracked lung, pulmonary edema, pneumocystis jirovecii pneumonia (PJP), pulmonary contusion, and more recently, Coronavirus disease 2019 (COVID-19) pneumonia. Knowledge of the many etiologies of this pattern can be useful in preventing diagnostic errors. In addition, although the etiology of subpleural sparing pattern is frequently indistinguishable during an initial radiologic evaluation, the differences in location of opacities in the lungs, as well as the presence of additional radiologic findings, patient history, and clinical presentation, can often be useful to suggest the appropriate diagnosis. We did a comprehensive search on Pubmed and Google Scholar database using keywords of "subpleural sparing," "peripheral sparing," "sparing of peripheries," "CT chest," "chest imaging," and "pulmonary disease." This review aims to describe the primary differential diagnosis of subpleural sparing pattern seen on chest imaging with a strong emphasis on clinical and radiographic findings. We also discuss the pathogenesis and essential clues that are crucial to narrow the differential diagnosis.

Typical chest CT features can determine the severity of COVID-19: A systematic review and meta-analysis of the observational studies

Background

It remains unclear whether a specific chest CT characteristic is associated with the clinical severity of COVID-19. This meta-analysis was performed to assess the relationship between different chest CT features and severity of clinical presentation in COVID-19.

Methods

PubMed, Embase, Scopus, web of science databases (WOS), Cochrane library, and Google scholar were searched up to May 19, 2020 for observational studies that assessed the relationship of different chest CT manifestations and the severity of clinical presentation in COVID-19 infection. Risk of bias assessment was evaluated applying the Newcastle-Ottawa Scale. A random-effects model or fixed-effects model, as appropriately, were used to pool results. Heterogeneity was assessed using Forest plot, Cochran's Q test, and I2. Publication bias was assessed applying Egger's test.

Results

A total of 18 studies involving 3323 patients were included. Bronchial wall thickening (OR 11.64, 95% CI 1.81–74.66) was more likely to be associated with severe cases of COVID-19 infection, followed by crazy paving (OR 7.60, 95% CI 3.82–15.14), linear opacity (OR 3.27, 95% CI 1.10–9.70), and GGO (OR 1.37, 95% CI 1.08–1.73). However, there was no significant association between the presence of consolidation and severity of clinical presentation (OR 2.33, 95% CI 0.85–6.36). Considering the lesion distribution bilateral lung involvement was more frequently associated with severe clinical presentation (OR 3.44, 95% CI 1.74–6.79).

Conclusions

Our meta-analysis of observational studies indicates some specific chest CT features are associated with clinical severity of COVID-19.

A 16-Year-Old Boy With Cough and Fever in the Era of COVID-19

A 16-year-old white boy with a history of chronic lung disease of prematurity, cough-variant asthma, and incidental lung nodules presented to the emergency center in spring 2020 with acute onset dry cough, shortness of breath, and fever. An initial history, gathered from his mother because of the patient's respiratory distress, revealed no recent travel. However, his mother is a health care worker at a hospital, and sick contacts included ongoing contact with a friend with cold-like symptoms. He had a variety of animals at home, including a dog, cats, fish, rodents, and reptiles. He had a history of vaping tobacco products >6 months ago. Fever and respiratory symptoms were associated with fatigue, chest tightness, abdominal pain, and myalgias. On examination, he was ill appearing and had tachycardia, tachypnea, borderline hypoxia with an oxygen saturation of 91% on room air, diminished breath sounds at the lung bases, and unremarkable abdominal examination results. A chest radiograph was consistent with the lung examination, revealing bilateral lower lobe hazy infiltrates. He showed initial improvement for 48 hours with antibiotics, intravenous fluid resuscitation, oxygen via nasal cannula, albuterol, and prednisone. Subsequently, he worsened with persistent high fever, increasing respiratory distress with pulmonary findings, and severe persistent epigastric pain, which added a layer of diagnostic complexity. As this patient's clinical course evolved and further history became available, pulmonary medicine and infectious diseases services were consulted to guide diagnostic evaluation and treatment of this patient early in the era of coronavirus disease 2019.