title: Viral pneumonias in adults: radiologic and pathologic findings.
abstract: Numerous viruses, including influenza virus, measles virus, Hantavirus, adenovirus, herpesviruses, varicella-zoster virus, cytomegalovirus, and Epstein-Barr virus, can cause lower respiratory tract infection in adults. Viral pneumonia in adults can be classified into two clinical groups: so-called atypical pneumonia in otherwise healthy hosts and viral pneumonia in immunocompromised hosts. Influenza virus types A and B cause most cases of viral pneumonia in immunocompetent adults. Immunocompromised hosts are susceptible to pneumonias caused by cytomegalovirus, herpesviruses, measles virus, and adenovirus. The radiographic findings, which consist mainly of patchy or diffuse ground-glass opacity with or without consolidation and reticular areas of increased opacity, are variable and overlapping. Computed tomographic findings, which are also overlapping, consist of poorly defined centrilobular nodules, ground-glass attenuation with a lobular distribution, segmental consolidation, or diffuse ground-glass attenuation with thickened interlobular septa. The radiologic findings reflect the variable extents of the histopathologic features: diffuse alveolar damage (intraalveolar edema, fibrin, and variable cellular infiltrates with a hyaline membrane), intraalveolar hemorrhage, and interstitial (intrapulmonary or airway) inflammatory cell infiltration. Clinical information such as patient age, immune status, community outbreaks, symptom onset and duration, and presence of a rash remain important aids in diagnosis of viral causes.
authors.affiliation: Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Ilwon-Dong, Kangnam-Ku, Seoul 135-710, Korea.
authors.forename: Eun A
authors.initials: EA
authors.lastname: Kim
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
authors.forename: Steven L
authors.initials: SL
authors.lastname: Primack
authors.forename: Hye Kyung
authors.initials: HK
authors.lastname: Yoon
authors.forename: Hong Sik
authors.initials: HS
authors.lastname: Byun
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Kim
authors.forename: Gee Young
authors.initials: GY
authors.lastname: Suh
authors.forename: O Jung
authors.initials: OJ
authors.lastname: Kwon
authors.forename: Joungho
authors.initials: J
authors.lastname: Han
mesh_terms: D000258:Adenovirus Infections, Human / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D018804:Hantavirus Pulmonary Syndrome / Q000000981:diagnostic imaging / Q000473:pathology; D006566:Herpesviridae Infections / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D007251:Influenza, Human / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008457:Measles / Q000000981:diagnostic imaging / Q000473:pathology; D011024:Pneumonia, Viral / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D011859:Radiography