What is linear fibrosis

I recently had a CT scan, kidney stone protocol. One thing the report said was "Linear Fibrosis is noted in the left lung base". I used to smoke, both tobacco and marijuana, but have stopped: tobacco 5 years ago, mj a year ago. I can imagine that linear fibrosis is simply a matrix of straight fibers in the base of my lung; my question is, is this something I should be concerned about?  Thanks!

[Venetia255]

I was given the exact same results after a CAT scan last week by my urologist's nurse and was surprised that a kidney scan result would include a lung. The nurse said the doctor would discuss this with me during my next app't.  I quit smoking 25 years ago. So I don't know the answer to your question and obviously am just as interested as you in finding out.