SOAPED into FM, Want to go into Rads

I hope this is appropriate to post here. I SOAPed into an FM spot in round 1. I wanted to do a TY truly, but I didn't get an offer in round 1. Is it possible for me to do 1 year of FM and match or residency swap into a PGY2 radiology program? Do any of you have any experience with this? Also not sure when I would take STEP 3 or apply or even talk to my PD about my desire. Any help is appreciated.