Diagnostic accuracy of chest radiography for the diagnosis of tuberculosis (TB) and its role in the detection of latent TB infection: a systematic review.

In this systematic review we evaluate the role of chest radiography (CXR) in the diagnostic flow chart for tuberculosis (TB) infection, focusing on latent TB infection (LTBI) in patients requiring medical treatment with biological drugs. In recent findings, patients scheduled for immunomodulatory therapy with biologic drugs are a group at risk of TB reactivation and, in such patients, detection of LTBI is of great importance. CXR for diagnosis of pulmonary TB has good sensitivity, but poor specificity. Radiographic diagnosis of active disease can only be reliably made on the basis of temporal evolution of pulmonary lesions. In vivo tuberculin skin test and ex vivo interferon-gamma release assays are designed to identify development of an adaptive immune response, but not necessarily LTBI. Computed tomography (CT) is able to distinguish active from inactive disease. CT is considered a complementary imaging modality to CXR in the screening procedure to detect past and LTBI infection in specific subgroups of patients who have increased risk for TB reactivation, including those scheduled for medical treatment with biological drugs.