The high value of high-resolution computed tomography in predicting the activity of pulmonary tuberculosis.

SETTING

A 2500-bed medical centre in southern Taiwan.

OBJECTIVE

To study the clinical value of high-resolution computed tomography (HRCT) in predicting the activity of pulmonary tuberculosis (TB).

DESIGN

HRCTs were performed prospectively in 148 patients whose chest radiographs (CXRs) showed highly suspicious signs of pulmonary TB, predominantly upper lung field infiltration. The HRCT findings, interpreted independently by a pulmonologist and a radiologist, were used to predict the activity of pulmonary TB.

RESULTS

Pulmonologist-interpreted and radiologist-interpreted HRCTs showed high sensitivity (both 93%), specificity (83 vs. 88%), accuracy (86 vs. 90%), positive predictive values (76 vs. 83%) and negative predictive values (both 95%). Kappa statistic indicates good inter-reader agreement.

CONCLUSION

HRCT has a high value in predicting the activity of pulmonary TB. It is a useful tool in this regard when a patient with suspected pulmonary TB lacks microbiologic proof, when clinical condition makes invasive diagnosis impossible or when a patient has completed anti-tuberculosis treatment with no compatible unequivocal CXR.