Diffuse Parenchymal Abnormalities in Acutely Dyspneic Patients: A Pattern-based Approach

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.

COVID-19 and its Mimics: What the Radiologist Needs to Know

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the current outbreak of Coronavirus disease 2019 (COVID-19). Although imaging should not be used for first-line screening or diagnosis, radiologists need to be aware of its imaging features, and those of common conditions that may mimic COVID-19 pneumonia. In this Pictorial Essay, we review frequently encountered conditions with imaging features that overlap with those that are typical of COVID-19 (including other viral pneumonias, chronic eosinophilic pneumonia, and organizing pneumonia), and those with features that are indeterminate for COVID-19 (including hypersensitivity pneumonitis, pneumocystis pneumonia, diffuse alveolar hemorrhage, pulmonary edema, and pulmonary alveolar proteinosis).

Imaging of Cardiopulmonary Involvement in Systemic Immune-mediated Diseases: A Comprehensive Review

Systemic immune-mediated diseases (SID) are a large group of disorders characterized by complex inflammatory and autoimmune damage to various organs and tissues. Among the possible manifestations, SIDs may potentially involve each structure of the cardiopulmonary system. Each disease is characterized by a specific clinical presentation. Coronary artery disease, myocarditis, pericarditis, valvular disease, pulmonary arterial hypertension, and interstitial lung disease represent characteristic findings of cardiopulmonary involvement in these disorders and their prompt recognition is crucial for the diagnosis of SIDs and the patient's prognosis. In this setting, chest high-resolution computed tomography and cardiac magnetic resonance are the most important noninvasive techniques for the assessment of these diseases and their complications. The knowledge of various cardiac and pulmonary radiologic patterns increases the likelihood of diagnosing these disorders and can lead to improved understanding of the underlying pathophysiology to personalize the treatment for each patient.