Objectives: 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. Key Points: • 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.
Bibliographical noteFunding Information:
The scientific guarantor of this publication is Jae-Joon Yim, M.D. The authors of this manuscript declare no relationships with any companies whose products or services may be related to the subject matter of the article. This study has received funding from the Seoul National University College of Medicine Research Fund (Grant number: 04-2014-290). The Medical Research Collaborating Center (MRCC) of Seoul National University College of Medicine kindly provided statistical advice for this manuscript. Institutional Review Board approval was obtained. The study protocol was approved by the Institutional Review Board of Seoul National University Hospital. Written informed consent was waived by the Institutional Review Board. Some study subjects or cohorts have been previously reported in Lee A-R, Lee J, Choi S-M, et al. Phenotypic, immunologic, and clinical characteristics of patients with nontuberculous mycobacterial lung disease in Korea. BMC infectious diseases. 2013;13(1):558. Methodology: retrospective, diagnostic or prognostic study, performed at one institution. Clinical Trial Registration: ClinicalTrials.gov (NCT02340897).
© 2016, European Society of Radiology.
All Science Journal Classification (ASJC) codes
- Radiology Nuclear Medicine and imaging