title: Psittacosis presenting as a halo sign on high-resolution computed tomography.
abstract: Psittacosis is an infectious disease caused by the intracellular microorganism Chlamydia psittaci, which mainly affects the respiratory tract. We described the high-resolution computed tomography findings in a 30-year-old man with psittacosis acquired by contact with psittacides. The diagnosis was confirmed by serological methods. High-resolution computed tomography showed nodular opacities surrounded by ground-glass attenuation (halo sign) in both lower lobes. Psittacosis should be considered in the differential diagnosis of pulmonary nodules with a halo sign in patients with a history of exposure to birds.
authors.affiliation: Santa Casa de Misericórdia de Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Hochhegger
authors.forename: Edson
authors.initials: E
authors.lastname: Marchiori
authors.forename: Klaus L
authors.initials: KL
authors.lastname: Irion
authors.forename: Gustavo
authors.initials: G
authors.lastname: Santos de Melo
authors.forename: Flávia
authors.initials: F
authors.lastname: Mendes
authors.forename: Gláucia
authors.initials: G
authors.lastname: Zanetti
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003937:Diagnosis, Differential; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000382:microbiology*; D008297:Male; D009956:Psittacosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D000900:Anti-Bacterial Agents