What Does Shadow In Fallopian Tube Signify?

I have had to have a scan, as have found it hard to fall pregnant. They done an internal scan and have found a shadow in my left fallopian tube. I'm getting really worried about this. I keep thinking they are going to have to remove the ovary and fallopian tube. I have had surgery before, which they found i had PID and Fitz Hugh Curtis. They removed the scarring and the adhesions. This was treated by being cut away and antibiotics.