Good point about the sinus CTs. I think the main question from this group has to do with serial CTs for research. I totally agree with you on the need for occasional, appropriate, CTs for diagnosis and treatment. Unfortunately, the picture (ha–no pun intended!) is not as clear for CTs for strictly research purposes.
Bronchoscopy is not done as frequently in CF and PCD today because HRCT is frankly much better for seeing small airways (where bronchiectasis starts) and for providing clear and measurable evidence of disease progression–plus it is non-invasive. A bronchoscope can not get much past the first several branchings of the bronchi so it can be easy to miss bronchiectasis that is getting started in the outside tiny bronchioles. Also, there are risks with bronchoscopy that are of more immediate concern than the still unclear radiation risks of CT scan. Bronchs almost always require some form of sedation or anesthesia, which is clearly a risk factor. They also are invasive, which is why you need to sign a consent, like a surgical consent, for the procedure. It is extremely unlikely, but possible, that an artery could be nicked or some other procedure-related incident could leave you in worse shape after the fact than when you went it. Also, there is a small but real risk of introducing a nasty bug into the lungs from an improperly sterilized scope. There are, thankfully extremely rare, accounts of this in medical journals. I also suspect there is a big cost difference between a simple HRCT (which is expensive enough) and a procedure that requires specialized personnel.
Bronchoscopy is still a very valuable tool, though. It seems to be reserved now for cases where the diagnosis is questionable and eyeball visualization may provide some clues or for when it can do “double duty” e.g. help retrieve good sputum cultures while performing a therapeutic task like removing mucus plugs, lavage (see below), or cauterizing bleeding vessels, etc.
My son, who does not have PCD, recently had a bronch because he had a nasty pneumonia, was in the hospital for a week, and despite scans, blood tests, etc. they could not figure out what was causing it. He was not responding to treatment, so the decision was to do a bronch and a bronchial alveolar lavage (BAL) which is essentially a lung “washing.” The
fluid that comes back is sent for lab analysis and culture. In his case, the bronch was very helpful because the BAL fluid grew a fungus called Cocci which is responsible for Valley Fever. Antibiotics won’t work for fungus, he need anti-fungals, so the bronch helped direct his treatment.
Bronchs are being used much more frequently in other disease states, like lung cancer, now. There is a whole new area of medicine called “interventional bronchoscopy” focused on providing therapy via bronchoscopy. It is mostly used in lung cancer, but maybe it will prove to be effective in the future for bronchiectasis, as well.