I am starting tests (CT, PFT, etc) for my eighteen month checkup on lung nodules. I also had one ground glass one last time around; but nothing had grown within the first six months. I do not perceive any symptoms. I am now on D3, and there was an NIH article on low D3 being a possible cause of nodules. In any case, this whole process can be unnerving, but other comments have been reassuring on this journey.