Just a note about the probable MAC diagnosis from CT…
I did have a horrid cough, but my bronchiectasis was caught because of follow-up CT done for another reason that had showed a couple nodules. Local and Mayo readiogists and pulmonologists thought I had MAC. Hard to produce cultures didn’t grow it, so I had bronch to get good sample. It was negative for MAC! I’d been very concerned, so great relief. I hope that is case for you.

The radiologists have continued to add that comment about MAC to explain the trees-in-bud and mucus impactions on CT and I asked my pulmonologist about it. He said radiologist love to add potential causes.
I have mild bronchiectasis and do airway clearance and no longer have the coughs. Good luck!.