title: Non-tuberculous mycobacterial lung disease: diagnosis based on computed tomography of the chest.
abstract: OBJECTIVE
  To elucidate the accuracy and inter-observer agreement of non-tuberculous mycobacterial lung disease (NTM-LD) diagnosis based on chest CT findings.
  
  
  METHODS
  Two chest radiologists and two pulmonologists interpreted chest CTs of 66 patients with NTM-LD, 33 with pulmonary tuberculosis and 33 with non-cystic fibrosis bronchiectasis. These observers selected one of these diagnoses for each case without knowing any clinical information except age and sex. Sensitivity and specificity were calculated according to degree of observer confidence. Inter-observer agreement was assessed using Fleiss' κ values. Multiple logistic regression was performed to elucidate which radiological features led to the correct diagnosis.
  
  
  RESULTS
  The sensitivity of NTM-LD diagnosis was 56.4 % (95 % CI 47.9-64.7) and specificity 80.3 % (73.1-86.0). The specificity of NTM-LD diagnosis increased with confidence: 44.4 % (20.5-71.3) for possible, 77.4 % (67.4-85.0) for probable, 95.2 % (87.2-98.2) for definite (P < 0.001) diagnoses. Inter-observer agreement for NTM-LD diagnosis was moderate (κ = 0.453). Tree-in-bud pattern (adjusted odds ratio [aOR] 6.24, P < 0.001), consolidation (aOR 1.92, P = 0.036) and atelectasis (aOR 3.73, P < 0.001) were associated with correct NTM-LD diagnoses, whereas presence of pleural effusion (aOR 0.05, P < 0.001) led to false diagnoses.
  
  
  CONCLUSIONS
  NTM-LD diagnosis based on chest CT findings is specific but not sensitive.
  
  
  CONCLUSIONS
  • Diagnosis of NTM-LD based on radiological findings showed high specificity. • Sensitivity of NTM-LD diagnosis was around 50 %. • Inter- observer agreement was moderate. • Identification of tree-in-bud pattern, consolidation and atelectasis led to correct diagnoses.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul, 110-744, Republic of Korea.
authors.forename: Nakwon
authors.initials: N
authors.lastname: Kwak
authors.affiliation: Department of Radiology, and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Chang Hyun
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Radiology, and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Division of Pulmonology, Department of Internal Medicine, Severance Hospital, Institute of Chest Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Ae
authors.initials: YA
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Gyeonggi-do, Republic of Korea.
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul, 110-744, Republic of Korea.
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Han
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul, 110-744, Republic of Korea. yimjj@snu.ac.kr.
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Yim
mesh_terms: D000368:Aged; D001987:Bronchiectasis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009165:Mycobacterium Infections, Nontuberculous / Q000000981:diagnostic imaging*; D015588:Observer Variation; D016017:Odds Ratio; D001261:Pulmonary Atelectasis / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging*
keywords: Computed tomography; Diagnosis; Inter-observer variation; Nontuberculous mycobacteria; Sensitivity and specificity