Most leaks are in the port or tubing.
I agree with DrewsLou
The contrast is called Omniplaque to be used during a flouroscopy/live X-ray.
Here's a bit of my story...
My old band was an AMI-swedish band that was installed 8/14/03 by Dr. Sanchez. After about 6 months and 4 fills I had a flouro/X-ray check which revealed a kink in the tubing. Well I suspected a leak, then confirmed it over 4 months later in mex, cause Dr. Sanchez recomended I go see him. At that visit the tubing was repaired and I was given a 7cc fill (big band), a month later my doctor (McKeen) here in Calif. did a flouro fill and that's when we saw that the repair didn't work. Back to mex I went and Dr. Sanchez decided to reband me, free (the makers of the AMI band is paying for it). I was rebanded with the 9.75 (smaller) Inamed band, big difference. I felt restriction right away. I couldn't gulp anymore either.
I'm very happy with my new band. I've only had one fill in 8/05 of 1.3cc's and to this day I can barely eat more than a cup of anything, if that.
It is RARE to be rebanded due to a leak!
I also want to suggest that some saline can come out of the port when they pull out the needle while doing a fill.
Good luck to you and you too DrewsLou