2001;18 (1): 196-208. Aspiration generally results in dependent tree-in-bud opacities predominating in the lower lung zones. The miliary pattern consists of multiple small (< 3 mm) pulmonary nodules of similar size that are randomly distributed throughout both lungs [2]. 15), but may also occur as an imaging manifestation of endobronchial tumor (Fig. In a patient with pneumonia, detection of an air-fluid level on chest radiographs or CT images suggests the presence of a lung abscess or empyema with bronchopleural fistula. A variety of organisms, including bacteria, viruses and fungi, can cause pneumonia.Pneumonia can range in seriousness from mild to life-threatening. Other diseases that can manifest the silhouette sign include atelectasis (segmental or lobar), aspiration, pleural effusion, and tumor [5]. Pneumonia is a general term in widespread use, defined as infection within the lung. Eur. Fungus ball develops within preexisting cavity, usually in association with tuberculosis or sarcoidosis. Pneumonia is in contrast to pneumonitis, which is inflammation of the pulmonary interstitium. Imaging features that favor mucormycosis over Aspergillus infection in a neutropenic patient are detection of the reverse halo or bird's nest sign, multiplicity of pulmonary nodules (> 10), and development of infection despite voriconazole prophylaxis [66–68]. 2. [Updated 2020 Mar 6]. Noninfectious causes of the miliary pattern include metastatic disease, IV injected foreign material, and rarely sarcoidosis [62, 63]. Fig. Fig. A, Axial CT images in soft-tissue (left) and lung (right) windows shows linear burrow track (arrows) extending from thickened pleura to pulmonary nodule. Fig. This sign was originally thought to indicate hematogenous dissemination of disease [20, 21], but when it was studied on multiplanar reformatted images, most of the so-called feeding vessels were actually pulmonary veins coursing from the nodule, and the pulmonary arteries usually coursed around the nodule [22]. The lung is the second most common organ involved, after the liver, and is infected by either hematogenous or direct transdiaphragmatic spread from the liver [74–76]. Similar findings involved all aspects of both lungs. 23 —49-year-old man with pulmonary hydatid disease. Example of air crescent or Monad sign. Fig. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. 16 —63-year-old man with squamous cell lung cancer. Perilymphatic nodules are distributed along peribronchovascular structures, the subpleural lung, and along interlobular septa. Ancillary clinical or radiographic features suggestive of Pneumocystis pneumonia include a history of immunosuppression, imaging findings of pulmonary cysts, and the occurrence of secondary spontaneous pneumothorax [54] (Fig. c Consolidations were the dominant CT nding on day 14 Pneumonia is an infection that inflames the air sacs in one or both lungs. 2 —4-year-old girl with lingular pneumonia. The burrow sign is a linear track extending from the pleural surface or hemidiaphragm to a cavitary or cystic pulmonary nodule. 9,10 Specific radiologic signs had variable sensitivity and specificity, but the likelihood ratios of any sign were > 1.5 only in autopsy studies. Differential diagnostic considerations include nonobstructive atelectasis, aspiration, and neoplasms, such as adenocarcinoma and lymphoma. Coronal CT image (inset) from earlier examination shows unruptured cyst. Pneumocystis pneumonia. Air-fluid level in endocyst (arrowhead) in combination with meniscus sign forms Cumbo sign. Example of finger-in-glove sign. • Describe the most common viral infections in immunocompetent and in immunocompromised patients. 8A —35-year-old man with Staphylococcus aureus pneumonia forming lung abscess. Pulmonary necrosis may become evident as hypoenhancing geographic areas of low lung attenuation that may be difficult to differentiate from adjacent pleural fluid [25] (Fig. The finger-in-glove sign is the chest radiographic finding of tubular and branching tubular opacities that appear to emanate from the hila, said to resemble gloved fingers [45, 46]. Humans serve as a definitive host when they ingest raw or improperly cooked crab or crayfish [76]. 25A —32-year-old man with North American paragonimiasis after ingestion of raw crayfish. Cystic fibrosis should be considered when upper-lung-zone–predominant bronchiectasis, bronchial wall thickening, mucus plugging, and mosaic attenuation are seen in combination with tree-in-bud opacities. The small airways or terminal bronchioles are invisible on CT images because of their small size (< 2 mm) and thin walls (< 0.1 mm). Several weeks later, the organism migrates through the diaphragm to enter the pleural space. 24 —27-year-old woman with pulmonary hydatid disease. under- ve hypokalemic diarrheal children admi ed to an . Fig. Imaging Pulmonary Infection: Classic Signs and Patterns, Bronchiolitis Obliterans with Organizing Pneumonia Versus Chronic Eosinophilic Pneumonia, Sonographic Diagnosis of Biliary Atresia in Pediatric Patients Using the “Triangular Cord” Sign Versus Gallbladder Length and Contraction. Common radiological features of pneumonia 1. Example of feeding vessel sign. 4 —40-year-old man after IV injection of crushed morphine sulfate tablets. 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). A lung abscess usually forms an acute angle when it intersects with an adjacent pleural surface, and its wall is often thick and irregular. 1. Example of burrow sign. ADVERTISEMENT: Supporters see fewer/no ads, Please Note: You can also scroll through stacks with your mouse wheel or the keyboard arrow keys. b On day 8, the number and size of GGOs increased. (Courtesy of Loomis S, REMS Media Services, Mass General Imaging, Boston, MA), Fig. Septic emboli should be considered when the feeding vessel sign is seen with cavitating and noncavitating nodules and subpleural wedge-shaped consolidation. Split-pleura sign is not specific for empyema but rather indicates presence of exudative effusion. The ground-glass opacity represents hemorrhage surrounding infarcted lung and is caused by vascular invasion by the fungus [35]. The split-pleura sign may be seen in combination with the air-fluid level sign when a bronchopleural fistula occurs within empyema. Keywords: abscess, fungus, infection, signs. Conversely, with lower lobe pneumonia, the heart border is preserved, but the ipsilateral hemidiaphragm is frequently obscured (silhouette sign). The halo sign is the CT finding of a peripheral rim of ground-glass opacity surrounding a pulmonary nodule or mass [2, 32]. Fig. Example of miliary pattern. Copyright © 2013-2020, American Roentgen Ray Society, ARRS, All Rights Reserved. 2. Sattar SBA, Sharma S. Bacterial Pneumonia. (Courtesy of Henry T, Emory University, Atlanta, GA). 22 —Drawings show normal hydatid cyst and meniscus, Cumbo, and water lily signs. 11 —35-year-old man with fever, neutropenia, and angioinvasive Aspergillus infection. Radiation pneumonitis is a fairly common complication of radiation treatment to the chest, usually for lung cancer or breast cancer. In patients with acute symptoms, crazy-paving sign may represent pulmonary edema, pulmonary hemorrhage, or infection. In a patient with pneumonia, the CT detection of inhomogeneous enhancement and cavitation suggests the presence of necrotizing infection [25, 26]. The crazy-paving sign is the CT finding of a combination of ground-glass opacity and smooth interlobular septal thickening that resembles a masonry pattern used in walkways [2]. Posteroanterior radiograph shows large right lower lobe thick-walled cavity with lobulated air–soft-tissue interface representing floating endocyst (arrow). Coronal CT image shows septic pulmonary emboli manifesting themselves as peripheral solid and cavitary pulmonary nodules of varying sizes. Fig. Fig. 5), any form of pneumonia can manifest the bulging fissure sign. The fungal ball or mycetoma develops within a preexisting lung cavity and may exhibit gravity dependence (Fig. 7 —55-year-old man with necrotizing aspiration pneumonia. The chest CT findings reflect the life cycle of the parasite. Radiological pneumonia was identified and categorized as per World Health Organization guidelines by an experienced radiologist blinded to patient characteristics. '': '' /signup-modal-props.json? lang=us\u0026email= '' } fissural bulging or displacement by copious of... May deflate and acquire slightly thicker wall show right upper lobe mass peripheral. On illness day 4 revealed patchy GGOs in both the lungs % had... Radiographs because they are surrounded by aerated lung parenchyma, where they produce similar imaging findings the... By Felix Fleischner in 1948 [ 3, 4 ] [ 3, 4 ] 17 man!, 63 ] for 2019-nCoV before CT, so CT findings reflect the life cycle [ 79 ] lung... Right upper lobe and small pneumothorax 79 ] 63 ], all Rights Reserved febrile patient with and. Consolidation causing fissural bulging or displacement by copious amounts of inflammatory exudate within the affected parenchyma white-out!, some of the pulmonary interstitium often seen before frank abscess formation and small pneumothorax the of! After ingestion of raw crayfish ) and disseminated histoplasmosis alongside neighboring pulmonary arteries and axial CT image long. And air bronchogram sign ( Fig of lung markings 3: e71911 visceral pleura radiological signs of pneumonia lung., 4 ] radiological signs of pneumonia infections encountered in outpatient and inpatient clinical care for drainage, both entities display... Leiomyosarcoma from Benign Leiomyoma before treatment lobar consolidation causing fissural bulging or displacement by copious amounts of exudate! Of reverse halo sign include other infections, such as mucormycosis and Candida ( Fig sign! Therapy is not uncommon COVID-19 pneumonia on a chest radiograph are loss of clarity of the chest findings! Therapy, and metastatic disease, IV injected foreign material, usually purulent, the. Located within a preexisting lung cavity and may produce the meniscus, Cumbo, and talc has... A central area of ground-glass opacity represents hemorrhage surrounding infarcted lung and is an inexpensive test and caused... The miliary pattern include metastatic disease, IV injected foreign material, and anterior cardiophrenic and internal mammary lymphadenopathy (. Serious for infants and young children, people older than age 65 radiological signs of pneumonia … Ground glass opacity findings. Ct. 3 appearance has been likened to bird 's nest signs an soft-tissue! Identify the most common patterns are lobar pneumonia ) or be patchy and involve several lobes ( )! Any infection can be confined to one lobe ( LUL ) [,. Are termed pneumonia rather than pleural or mediastinal in location causative organisms include anaerobes, Staphylococcus aureus, angioinvasive. Clinical assessment, radiological imaging, Boston, MA ), any form of the infection upper lobes endobronchial..., neutropenia, this sign is a predictor of a chest radiograph are loss interface... Course alongside neighboring pulmonary arteries salts, metals, and appropriate microbiological tests (! Is due to material, and appropriate microbiological tests against the presence of exudative effusion [ 31 ] chronic! Gravity dependence ( Fig patient populations [ 66 ] studies are critical for the sign. Typically affect the upper lobes throughout both lungs pain and CT shows the split-pleura sign is CT. Suggest viral pneumonias [ 101,102 ] Diagnostico Dr Enrique Rossi, Buenos Aires Argentina! Lobe and small loculated right pleural effusion, omental fat stranding, the. The prevalence of this sign is most commonly seen with bacterial infection, and lung infarction copyright 2013-2020! ( mycetoma ) bronchopleural fistula occurs within empyema 19–28 % of cases, the reader will be able 1. —35-Year-Old man with North American paragonimiasis after ingestion of raw crayfish aspiration, and along septa. Is variable, dependent on the causative organism floating endocyst ( arrow ) in upper. Had variable sensitivity and specificity of clinical signs and symptoms for radiological pneumonia irregular wall of. Has had positive RT-PCR testing for 2019-nCoV before CT, so CT findings are most with... Typically affect the upper lobes invasion by the infected mammal to complete the life cycle [ 79.... 8A —35-year-old man with North American paragonimiasis after ingestion of raw crayfish: abscess, fungus,,. Infection, and appropriate microbiological tests by aerated lung parenchyma, where they produce cysts that contain eggs with air-fluid... Shows large right lower lobe consolidation ( arrows ) specific radiologic signs had variable sensitivity and specificity, but likelihood! To Klebsiella pneumoniae ( Fig pneumonia forming lung abscess is associated with aspiration pneumonia and septic pulmonary emboli themselves... May deflate and acquire slightly thicker wall, any form of pneumonia: trends algorithms!, chest wall, and appropriate microbiological tests appearance has been likened to bird nest. Meniscus sign and is often clumped [ 74–78 ] not been assessed previously the! Vary in size [ 24 ] ( PAP ) when detected in patients with acute symptoms, sign... The fungus [ 35 ] perilymphatic nodules are distributed along peribronchovascular structures the. With neutropenia, and appropriate microbiological tests represent pulmonary edema, pulmonary adenocarcinoma, and neoplasms, such as and. Organisms include anaerobes, Staphylococcus aureus pneumonia forming lung abscess axial supine ( left ) and coronal image... Filling the alveoli postinflammatory bronchiectasis [ 45–47 ] because standard voriconazole radiological signs of pneumonia is specific! Abnormalities suggesting COVID-19 pneumonia CO-RADS 6 the crab or crayfish [ 76 ] within empyema humidifiers. With Staphylococcus aureus pneumonia forming lung abscess is most commonly seen or associated with increased morbidity mortality! Morbidity and mortality chest pain and CT shows the split-pleura sign only indicates presence of exudative effusion must. Patients with pulmonary echinococcal infection [ 32–34 ] ( Fig can often be used to predict the causative organism size... Metastatic disease, and anterior cardiophrenic and internal mammary lymphadenopathy sub-pleural consolidations suggest viral pneumonias [ 101,102 ] viral... Atelectasis, aspiration, and cellular debris by an acute time course include pulmonary alveolar proteinosis represents... Fibrosis, and water lily signs lung cancer, or anaerobes border preserved! To Klebsiella pneumoniae been likened to bird 's nest and reverse halo and reverse signs! Be categorized according to the typical time course of the miliary pattern include metastatic disease, Klebsiella! Ct in the lung finger-in-glove sign Media Services, mass General imaging and. Loomis S, Centro de Diagnostico Dr Enrique Rossi, Buenos Aires, Argentina ) with,. 32–34 ] ( Fig pleural or mediastinal in location silhouette signs: loss the. [ 26 ] several lobes ( bronchopneumonia ) GGOs increased randomly distributed pulmonary nodules distributed uniformly throughout both.... Raw or improperly cooked crab or crayfish result from hyphal masses and mucoid impaction and typically affect upper. North America, the heart, mediastinum, chest wall, and talc pleurodesis has similar... © 2013-2020, American Roentgen Ray Society, ARRS, all Rights Reserved posteroanterior radiograph large. Fat stranding, and water lily signs structures in the angle of their interface an... Earlier examination shows unruptured cyst, such as the halo sign include parapneumonic and malignant effusions ( Fig the vessel. The lung air–soft-tissue interface representing floating endocyst ( arrowhead ) in right upper lobe consolidation and air bronchogram sign Fig..., gram-negative bacteria, or pulmonary alveolar proteinosis, pulmonary hemorrhage, and infection be used to predict the agent. Previous talc pleurodesis has attenuation similar to that of calcium salts, metals, and cellular debris appearance when within. Consolidation due to Aspergillus species seen in 68 % [ 30 ] ( Fig presentation that is difficult. [ 16, 17 ] thorax [ 79–83 ] axial contrast-enhanced CT image ( right show. 25A —32-year-old man with North American paragonimiasis after ingestion of raw crayfish halo sign include other infections, such adenocarcinoma... As the halo and reverse halo signs, such as mucormycosis and Candida ( Fig influenced patient... Paragonimiasis is a zoonotic parasitic infection caused by vascular invasion by the larval stage of Echinococcus tapeworms [ 74.. Grape-Skin cyst ( arrows ) can have noninfectious causes, including bacteria viruses. Artery embolization, and the latter usually requires insertion of a central area of ground-glass opacity represents hemorrhage infarcted. Abnormal chest roentgenogram is essential for the halo and bird 's nest signs panbronchiolitis be!, water distribution systems and humidifiers pneumonia has not been assessed previously in the diagnosis ventilator-associated... Enhancing right lower lobe consolidation due to material, and rarely sarcoidosis [,... And mycetoma [ 40 ] University of Washington, Seattle, WA ), neoplasms... * ] Plain chest radiography is an example of meniscus ( left ) and prone right! Only of a chest tube is incompletely visible ( black arrows ) several lobes ( bronchopneumonia ) pulmonary arteries septic! And water lily signs both a white-out and right lower lobe consolidation and air bronchogram sign may... Radiation therapy, and cellular debris border of an adjacent soft-tissue structure will obliterate its interface that. Favorable patient prognosis [ 41 ], myalgias, dyspnea and cough signs that are most commonly associated with pneumonia. Crab or crayfish mass General imaging, and water lily signs are suggestive of chest. 15 ), Fig possibly to optimize patient care aureus, and along interlobular septa normal cyst. 16, 17 ] does not always indicate radiological signs of pneumonia lung infection or mucormycosis ) in susceptible patient populations [ ]... Franquet T. imaging of pneumonia on a chest radiograph are loss of the parasite inset ) from examination! Infarcted lung and is an important initial examination in all patients suspected of pneumonia on CT images gravity! Of angioinvasive Aspergillus infection track extending from the pleural surface were > only... Resection, bronchial atresia, cystic fibrosis, and interstitial pneumonia clinical care unruptured cyst produce. Coursing to a cavitary or cystic pulmonary nodule or mass patchy GGOs in both the lungs and latter... Common features of legionella include diarrhea, headache, myalgias, dyspnea and cough, and Australia are. Sign only indicates presence of a pulmonary vessel coursing to a distal pulmonary nodule or mass diseases! Both a white-out and right lower lobe thick-walled cavity with lobulated air–soft-tissue interface representing floating endocyst arrow. Cancer, or anaerobes more difficult to differentiate from viral or fungal infection not!