Can Vascular Markings Interfere With Chest X Ray?

Thanks!
I had the flu two weeks ago and am suffering with a steady cough. Went to the urgent care today and had an xray. No pneumonia and the doctor said that I have bronchitis and exacerbation of my asthma. When I asked her about the chest xray and what it showed all she could say was that it was hard to tell if there was any small amount of infiltrate because of my "vascular markings". When I pressed her to explain she didn't. I am wondering how "vascular markings" could interfere with a chest xray? I have a lot of rhonchi and wheezing throughout all my lung fields.