Yes, you can introduce ich with corals, invertebrates, anything wet. That's why most experts recommend quarantining everything you get for 6 weeks. But alot of people on this site just take their chances and many have ich but their fish build resistance to it if they are low stressed by not being overstocked, etc. but a new fish coming in could get it and die. I'm going to start quarantining everything because I think I got ich from getting coral from my LFS tanks that had fish with the coral. Even if your LFS doesn't have fish in their coral tanks they could have just gotten a shipment with coral that was living with fish last week.