Does Presence Of Bullae In Lungs Indicate Lung Collapse?

Hi, I have severe copd and a few months ago had a ct scan done of the chest.There is a 10mm bulla in upper left lobe in addition to areas of subsegmental atelectasis in the lung bases bilaterally. Several nodules we also found. Does bulls mean I could have a collapsed lung?Could you please tell me about the other findi ngs as well? Thank you, Aimee