Can I adapt to learning Artificial intelligence in MS easily
I don't know about the US, but in some schools in Canada you can be admitted to a CS Graduate degree without prior background in an interest area. You'd have to take background courses to get yourself up to speed, possibly in excess of the bare-minimum program requirements, but it should be doable. 

For AI specifically, ensure that the schools you're applying to have enough background in the topic, and that there are supervisors and supervisory capacity for you. Look for undergraduate courses in topics that interest you, as they may form part of your background studies.