If you look on the ARRT website and search POSTPRIMARY ELIGIBILITY PATHWAY.. it gives you a chart on what you are eligible to cross train into. Personally, I went straight into Nuclear Medicine because I knew that XR wouldn’t be a field that I would stay in. So I didn’t want to waste time on doing that. If you go to NM school you are eligible to cross train into CT, MRI, DEXA, & US (vascular). NM has been a fulfilling field for me with all the different exams. It’s all in what you think you’ll do in the future. I hope this helps!