Bronchoscopy

Air reaches the lung through a set of tubes, and bronchoscopy means traveling that route and taking a look. The instrument for that job is the bronchoscope, which shows what those passages and the lungs look like from within. It comes in two kinds, one rigid and one bendable, and in practice the bendable one does nearly all of this work.

Once it is in position, the same instrument turns into a way of bringing material back out. Saline solution, which is water with salt in it, can be run through it; the liquid rinses the lung and comes back out loaded with microbes and with cells from inside the air sacs, the tiny air pockets inside the lung. Picture rinsing out an empty jar with water and then keeping the rinse water to find out what had been sitting in there. That maneuver has a name of its own: lavage. Small brushes, needles and forceps can travel down the same channel and return with fragments of tissue, and a fragment obtained that way is what gets called a biopsy. The procedure therefore earns its place twice over: it can establish which lung disease is present, and with certain lung conditions it can play a part in the treatment itself.