Role of digital tomosynthesis in the context of tuberculosis contact investigation: comparisons with digital radiography.

Background: Chest radiography value as a screening tool in those exposed to pulmonary tuberculosis (TB) is reduced by its lower sensitivity to detect small intrapulmonary lesions.

Purpose: To evaluate the efficacy of digital tomosynthesis (DTS) screening of individuals that had contacted persons with active TB using low-dose computed tomography (CT) as the reference standard methods.

Material And Methods: This retrospective, community-based screening study of 90 adults who had been in close contact with a TB case was undertaken at our institution. All individuals underwent clinical evaluation, digital radiography (DR), DTS, and low-dose chest CT. Observers assessed and classified DR and DTS images using CT as the reference-standard method. Based on clinical and imaging findings, TB status was classified as normal, latent, minimal, subclinical, and active. Diagnostic performances of DTS and DR for the interpretation of correct diagnosis were calculated.

Results: The estimated effective doses for DR, DTS, and low-dose CT were 0.01 mSv, 0.1 mSv, and 0.33 mSv, respectively. TB statuses of the 90 individuals were as follows: 62 latent (68.9%); two subclinical (2.2%); and one minimal (1.1%). The sensitivities, specificities, and accuracies of DTS and DR in the interpretation of correct diagnosis were 75.8%, 100%, 91.1% and 48.5%, 96.5%, 78.9%, respectively.

Conclusion: DTS appears to be superior to DR for the detection of lung lesions in individuals with TB contacts. DTS can offer a reasonable option for TB contact investigation.