A meta-analysis of homeless populations suggests that using chest radiography as a screening measure is sufficient and can lead in some cases to a decline in the incidence of TB over time [19]. This study, however, did not compare chest radiography screening to other screening strategies in terms of efficacy. Screening procedures vary from one prison site to another. There does not appear to be a large discrepancy in TB incidence regardless of screening technique (symptom survey, PPD, or chest radiograph) [22]. There is no evidence regarding the performance of routine radiography in low-risk patients who did not receive other TB screening before transfer to a group home or nursing facility. Computed tomography CT should be reserved for the rare case in which a chest radiograph is equivocal for active TB and more definitive testing such as sputum culture is impractical. Magnetic resonance imaging Like CT, there is a very limited role for MRI, although it might be considered when cross-sectional imaging is deemed necessary in a patient for whom there is a desire to avoid ionizing radiation. Summary of Recommendations Chest radiography is the first recommended test in patients with suspected tuberculosis. Chest radiography is generally appropriate for patients with new evidence of exposure or at high risk for development of tuberculosis, although it may be of low yield in patients who have no clinical symptoms. Chest CT is appropriate when tuberculosis is suspected and radiography is nonrevealing or nondiagnostic. Although there are references that report on studies with design limitations, 11 well-designed or good-quality studies provide good evidence. Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure.
Imaging of Possible Tuberculosis. A meta-analysis of homeless populations suggests that using chest radiography as a screening measure is sufficient and can lead in some cases to a decline in the incidence of TB over time [19]. This study, however, did not compare chest radiography screening to other screening strategies in terms of efficacy. Screening procedures vary from one prison site to another. There does not appear to be a large discrepancy in TB incidence regardless of screening technique (symptom survey, PPD, or chest radiograph) [22]. There is no evidence regarding the performance of routine radiography in low-risk patients who did not receive other TB screening before transfer to a group home or nursing facility. Computed tomography CT should be reserved for the rare case in which a chest radiograph is equivocal for active TB and more definitive testing such as sputum culture is impractical. Magnetic resonance imaging Like CT, there is a very limited role for MRI, although it might be considered when cross-sectional imaging is deemed necessary in a patient for whom there is a desire to avoid ionizing radiation. Summary of Recommendations Chest radiography is the first recommended test in patients with suspected tuberculosis. Chest radiography is generally appropriate for patients with new evidence of exposure or at high risk for development of tuberculosis, although it may be of low yield in patients who have no clinical symptoms. Chest CT is appropriate when tuberculosis is suspected and radiography is nonrevealing or nondiagnostic. Although there are references that report on studies with design limitations, 11 well-designed or good-quality studies provide good evidence. Relative Radiation Level Information Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure.