How much does an MRI cost in NYC? URGENT!!!

So, my grandfather is dealing with some chest pains. They’ve suggested a CT scan, but his primary care physician won't write the referral because there isn't enough clinical evidence yet to justify it. Does anyone know where in New York City I can get a CT scan done most affordably? What kind of pricing should I expect, and which clinic would you recommend?
Also, just to clarify—are a CT scan and an MRI actually the same thing?
Please send me a private message with any info so the admins don't lock this thread. Thanks.