Is it possible to use EMT certification to become a PCT
Assuming by "PCT" you mean "patient care technician", there's no standard for that. Facilities can set whatever requirements they want for the position (including no prior training at all).
PCT typically requires a CNA license. Nursing training is way different but not hard. You’ll do fine.
Not a PCT but I am an ER tech, and have been offered several "PCT" jobs. Mostly dialysis, sleep centers, PT. Not any of them terrible but defiantly not EMS nor anything to do with EMT School.
I like my job, but get ready to do a lot of CNA-ish stuff
I have my CNA and about to finish my EMT-B and both can be hired for PCT in my state. (Michigan) Most hospitals require one or the other for the position.
(I mostly see this listed for ER Tech)