Fungus ball develops within preexisting cavity, usually in association with tuberculosis or sarcoidosis. Pneumonia is the most common cause of death due to infectious diseases in the United States, with an incidence of 11.6 per 1000 persons/year reported in one study 4. However, a more insidious or diffuse presentation that is more difficult to differentiate from viral or fungal infection is not uncommon. In Pneumocystis pneumonia, the histologic features that produce the crazy-paving pattern are alveolar exudates containing the infective organisms and cellular infiltration or edema in the alveolar walls and interlobular septa [52, 53]. Some radiologists believe that the meniscus sign is suggestive of impending cyst rupture [76, 77]. Fig. Importantly, cavitation does not always indicate a lung infection or abscess. Over time the lesion may deflate, or it may rupture into the pleural space, the result being pneumothorax [56, 59]. The disease may be sporadic, though outbreaks have occurred from colonization of air conditioning towers, water distribution systems and humidifiers. Fig. This sign indicates that the underlying opacity must be parenchymal rather than pleural or mediastinal in location. 8A —35-year-old man with Staphylococcus aureus pneumonia forming lung abscess. The ground-glass opacity represents hemorrhage surrounding infarcted lung and is caused by vascular invasion by the fungus [35]. The bulging fissure sign is also less commonly detected in patients with hospital-acquired Klebsiella pneumonia than in those with community-acquired Klebsiella infection [19]. This study aimed to compare the clinical and radiological characteristics of SARS-CoV-2 and endemic HCoVs infection in adult hospitalized patients with community-acquired pneumonia (CAP). 19). Air-fluid level in endocyst (arrowhead) in combination with meniscus sign forms Cumbo sign. After finding mates, the parasites burrow through the visceral pleura into the lung parenchyma, where they produce cysts that contain eggs. Example of air bronchogram sign. 7 —55-year-old man with necrotizing aspiration pneumonia. The former typically requires medical treatment with antibiotics, and the latter usually requires insertion of a chest tube for drainage. Seven roentgenographic signs (air bronchograms, alveolar infiltrates, silhouette sign, cavities, fissure abutment, atelectasis, and … bacterial pneumonia than in COVID-19 pneumonia [18, 23] (Fig. Various imaging signs of thoracic infection can be clinically useful, sometimes suggesting a specific diagnosis and often narrowing the differential diagnosis. L. pneumophila is the organism responsible for Legionnaires disease or legionella pneumonia. Respir. Accreditation and Designation Statement The RSNA is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical educati… With bronchial erosion, air dissects between the outer pericyst and ectocyst to produce the meniscus sign (Fig. The term consolidation is often erroneously used as a synonym for pneumonia. The split-pleura sign may be seen in combination with the air-fluid level sign when a bronchopleural fistula occurs within empyema. 16 —63-year-old man with squamous cell lung cancer. The crazy-paving sign was originally described as a characteristic CT pattern detected in patients with pulmonary alveolar proteinosis. (Courtesy of Henry T, Emory University, Atlanta, GA). Patients occasionally present with pneumothorax [79–83]. Radiological features. Thick, irregular wall typical of lung abscess is evident. The purposes of this article are to describe common and uncommon imaging signs and patterns of pulmonary infections and to discuss their underlying anatomic and pathophysiologic basis. Recognizing the linear burrow track is the key to differentiating this entity from others, such as malignancy, fungal infection, and tuberculosis [80–83]. 12 —47-year-old man with disseminated candidiasis. Example of halo sign. Fig. The chest CT findings reflect the life cycle of the parasite. 24 —27-year-old woman with pulmonary hydatid disease. Aspiration generally results in dependent tree-in-bud opacities predominating in the lower lung zones. A, Posteroanterior radiograph shows branching tubular opacities (arrows) emanating from both hila. It is important to consider a diagnosis of bacterial pneumonia in a patient with fever and cough when the silhouette sign is detected at chest radiography. Example of tree-in-bud sign. 1 —49-year-old man with left lower lobe pneumonia. Example of finger-in-glove sign. (Courtesy of Loomis S, REMS Media Services, Mass General Imaging, Boston, MA), Fig. As classically described, the grape-skin sign is a solitary finding of a thin-walled cavity with central lucency that has been associated with chronic pulmonary coccidioidomycosis infection [57, 58] (Fig. 15), but may also occur as an imaging manifestation of endobronchial tumor (Fig. Region, Africa, and Klebsiella pneumoniae ( Fig useful, sometimes suggesting a specific diagnosis and of... Have noninfectious causes, including bacteria, or pneumonectomy the border of an exudative effusion and must be correlated clinical! Two types of Aspergillus infection: angioinvasive and mycetoma [ 40 ] differentiated from septic emboli should considered. 17 —24-year-old man with HIV infection and Pneumocystis pneumonia and mycetoma [ 40.... Mammal to complete the life cycle [ 79 ] aureus, and its appearance variable! 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