The positive bronchus sign in patients with known lung cancer.

The positive bronchus sign is the CT finding of a bronchus leading to or contained within the primary mass. A prospective study was performed for the purpose of establishing the correlation between the above sign on CT and the visual and pathological findings on bronchoscopy. The predictive value for the positive bronchus sign was found to be 94% and that of the negative bronchus sign 62%. CT is useful in predicting the likelihood of subsequent bronchoscopy providing positive results.