Early Diagnosis of Active Tuberculosis Using Ultra Low-dose Chest CT

Early Diagnosis of Active Tuberculosis Using Ultra Low-dose Chest CT to Predict Progression to Active Tuberculosis Among Contacts

The aim of this study is to evaluate ultra low dose chest computed tomography (ULDCT) for early diagnosis of active tuberculosis in cohort of close contacts of active pulmonary tuberculosis for 1 year follow up

The early diagnosis of active tuberculosis in close contacts have not yet been established. To evaluate the early detection of active pulmonary tuberculosis using ULDCT, the investigators will establish the observational cohort of close contacts living in the same space with active pulmonary tuberculosis. Participants will visit our center at enrollment, after 3 months, and 12 months and will be received ULDCT, chest X-ray and Interferon-gamma assays at each visit. One chest radiologist will interpret findings of ULDCT and chest X-ray. Patients diagnosed with active tuberculosis will be excluded from the study and treated based on World Health Organization guidelines.

Participants in the study will receive ULDCT at enrollment, after 3-month visit, and after 12-month visit.

Participants in the study will receive chest x-ray at enrollment, after 3-month visit, and after 12-month visit.

Participants in the study will receive IGRA test at enrollment, after 3-month visit, and after 12-month visit. About 11mL of blood will be drawn from the participants for test of T-SPOT®.TB test and QuantiFERON test.

Active pulmonary tuberculosis defined by WHO guidelines for treatment of drug-susceptible tuberculosis and patient care (2017 update)

Active pulmonary tuberculosis defined by WHO guidelines for treatment of drug-susceptible tuberculosis and patient care (2017 update)

Serial comparison analysis of CT findings in latent tuberculosis patients who diagnosed latent tuberculosis based on IFN-gamma assay

Inclusion Criteria: Close contacts of active pulmonary tuberculosis Family members of active TB patient who has lived together for more than one month, or work colleagues of active TB patient who has been working in the same office for more than 8 months Participants who received explanation of the research plan, understands and writes agreement. Exclusion Criteria: Vulnerable subjects with mental retardation or severe mental illness Patients who could not receive chest CT Pregnancy Close contacts who diagnosed active pulmonary tuberculosis

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