CT is a catscan.And when I Googled BAL test I found a site that said "A BAL is a broncho-alveolar lavage, which just means that they introduce some sterile saline into the airway then recollect it for examination".My son had a CT for his sinuses, but not the lavage. I would be concerned about water being left in the lungs??? Maybe some of the older CFers have had this done though.