title: High-resolution Computed Tomography Findings in Patients with Pulmonary Nocardiosis.
abstract: OBJECTIVE
  Nocardiosis is difficult to diagnose, and the diagnosis is thus frequently delayed. High-resolution computed tomography (HRCT) findings of patients with pulmonary nocardiosis have been documented in few reports. Our study objective was to assess HRCT findings of patients with pulmonary nocardiosis.
  
  
  METHODS
  This was a retrospective study of 20 consecutive patients with pulmonary Nocardia infections who underwent HRCT of the chest at our institutions from January 2011 to August 2014. After the exclusion of two patients with concurrent infections, the study group comprised 18 patients (11 men, 7 women; age range, 39-83 years; mean, 67.9 years) with pulmonary Nocardia infections. Parenchymal abnormalities, enlarged lymph nodes, and pleural effusion were evaluated on HRCT.
  
  
  RESULTS
  Underlying conditions included respiratory disease (n = 6, 33.3%), collagen diseases (n = 5, 27.8%), and diabetes mellitus (n = 4, 22.2%). All patients showed abnormal HRCT findings, including the presence of a nodule/mass (n = 17, 94.4%), ground-glass opacity (n = 14, 77.8%), interlobular septal thickening (n = 14, 77.8%), and cavitation (n = 12, 66.7%). Pleural effusion was seen in two patients. There were no cases of lymph node enlargement.
  
  
  CONCLUSIONS
  Among the HRCT findings in patients with pneumonia, a nodule/mass with interlobular septal thickening and/or cavitation are suggestive of pulmonary nocardiosis.
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Sato
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan. Electronic address: fumitook@oita-u.ac.jp.
authors.forename: Fumito
authors.initials: F
authors.lastname: Okada
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Mori
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan.
authors.forename: Asami
authors.initials: A
authors.lastname: Ono
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Nakayama
authors.affiliation: Department of Radiology, Oita Nishi Beppu National Hospital, Beppu, Oita, Japan.
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Ando
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Matsumoto
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Tanoue
authors.affiliation: Hospital Infection Control Center, Oita University Hospital, Yufu, Oita, Japan.
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Hiramatsu
authors.affiliation: Department of Respiratory Medicine, Oita Red Cross Hospital, Oita, Japan.
authors.forename: Takehiko
authors.initials: T
authors.lastname: Shigenaga
authors.affiliation: Department of Respiratory Medicine, Oita Red Cross Hospital, Oita, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hata
authors.affiliation: Department of Respiratory Medicine, Oita Koseiren Tsurumi Hospital, Beppu, Oita, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Kishi
authors.affiliation: Department of Radiology, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu, Oita, Japan.
authors.forename: Hiromu
authors.initials: H
authors.lastname: Mori
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003095:Collagen Diseases / Q000150:complications; D048909:Diabetes Complications / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008168:Lung / Q000000981:diagnostic imaging; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D009617:Nocardia Infections / Q000000981:diagnostic imaging*; D010996:Pleural Effusion / Q000000981:diagnostic imaging; D018410:Pneumonia, Bacterial / Q000000981:diagnostic imaging*; D012140:Respiratory Tract Diseases / Q000150:complications; D012189:Retrospective Studies; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging
keywords: High-resolution computed tomography; chest; community-acquired infection; nosocomial infection; pulmonary nocardiosis