J Korean Soc Radiol.  2021 Nov;82(6):1524-1533. 10.3348/jksr.2020.0160.

Chest Radiographs and CT Findings during Healthcare Workers’ Tuberculosis Screening Using InterferonGamma Release Assay: Retrospective Observational Study

• Choi YR
• Lee JK
• Heo EY
• Kim DK
• Jin KN

• KMID: 2522950
• DOI: http://doi.org/10.3348/jksr.2020.0160

Abstract

Purpose
To investigate the incidence of tuberculosis (TB) in healthcare workers (HCWs) with positive interferon-gamma release assay (IGRA) results based on chest X-ray (CXR) and CT findings and determine the role of imaging in the diagnosis of TB.
Materials and Methods
Among 1976 hospital personnel screened for TB using IGRA, IGRApositive subjects were retrospectively investigated. Clustered nodular and/or linear streaky opacities in the upper lung zone were considered positive on CXR. The CT findings were classified as active, indeterminate, inactive, or normal. The active or indeterminate class was considered CT-positive.
Results
IGRA was positive in 255 subjects (12.9%). CXR and CT were performed in 249 (99.2%) and 113 subjects (45.0%), respectively. CXR- and CT-positive findings were found in 7 of 249 (2.8%) and 9 of 113 (8.0%) patients, respectively. Among the nine CT-positive subjects, active and indeterminate TB findings were found in 6 (5.3%) and 3 (2.7%) patients, respectively. Microbiological tests, including acid-fast bacilli staining, culture, and polymerase chain reaction for TB, were negative in all nine CT-positive subjects. Empirical anti-TB medications were administered to 9 CT-positive subjects, and 3 of these nine subjects were CXR-negative for pulmonary TB.
Conclusion
CT helped diagnose asymptomatic TB in IGRA-positive HCWs.

Keyword

Thorax; X-Rays; Tomography; X Ray Computed; Tuberculosis; Interferon Gamma Release Tests