another spinal tap question

okay, so what is the difference between a spinal tap and a lumbar puncture?

I kept thinking I would be doing the test where you have to curl up and that helps them get the right spot. Apparently I will be laying flat on my stomach and this is some sort of CT guided lumbar puncture. Is this anything I need to be more concerned about? It just presents a completely different picture in my head than what I had been mentally preparing for.

Appreciate any feedback.

Thanks!!!