Bronchiolitis obliterans syndrome in lung transplant recipients: use of spirometrically gated CT.

PURPOSE

To assess the potential use of spirometrically gated lung computed tomographic (CT) findings in the diagnosis of bronchiolitis obliterans syndrome after lung transplantation.

MATERIALS AND METHODS

Forty-nine lung transplant recipients were examined at least 8 months after surgery with spirometrically gated thin-section CT of the lung. In addition to visual signs of small-airway disease at CT, mean lung attenuation and the SD were numerically determined and compared with the results of lung function testing at the time of the CT examination and 1 year later by using factorial analysis of variance.

RESULTS

Mean lung attenuation was significantly lower in patients who developed bronchiolitis obliterans syndrome within 1 year after the CT study (-837 HU +/- 3) than in patients with persistent normal lung function (-812 HU +/- 3, P <.001). With an optimal threshold, sensitivity was 69%, specificity was 71%, and accuracy was 84%. Visual analysis did not significantly contribute to the prognostic power of CT.

CONCLUSION

Spirometrically gated CT measurements of lung attenuation can be used to predict the onset of bronchiolitis obliterans syndrome after lung transplantation.