Tuberculosis: a review and update.

More than 2 billion people worldwide are infected with Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB). Nine million more are infected each year. Although extensively drug-resistant TB strains are very rare in the U.S., these strains represent a major emerging global public health challenge and likely will become more common in the U.S. in coming years. Diagnostic imaging plays an integral role in TB diagnosis, screening and control efforts, but the risk of occupational infection among radiologic technologists is unclear. This article discusses TB epidemiology, diagnosis, prevention, screening and treatment, as well as the role of diagnostic imaging.