Album Artwork Change?!? HELP

Last night I was importing new music on my phone, and I had unplugged my phone from my computer and then plugged it back in after adding some new songs into my iTunes library. When I plugged in my phone it automatically started to sync the songs. When it did this it changed some of my album artwork around to songs that were already on my phone. For example a song by Train has Beyonce artwork on it and a song by Demi Lovato has Katy Perry artwork.. Does anyone know how to fix this?