White spots on babies x ray?

Our 2 week year old son had an x ray to see if his pelvik harness was aligning his hips into the proper location. The good news is that his hips are going to be fine. However, areas around his liver appear to be white or light gray on the x ray. In other words, these large spots are not translucent as they are suppose to look. Our baby did have an echogentic bowel prior to birth, but ultra sounds monitored it as it faded and completely went away. We also tested for major syndromes su@h as downs and cf, and everything was fine. What could it be?