So after qualification, you can then choose to do a masters - its kind of expected if you want a band 7 role to at least be working towards your masters. If you want to be an Advanced Practitioner or Consultant Radiographer you will absolutely need postgrad qualifications.
I know some radiographers who have done a PgDip in Sonography (very competitive). You can go the academic route - if you want to be a lecturer you'll be expected to get some qualifications in education.
Other choices I've seen people make - recruitment, AHP role development, sales for equipment manufacturers, service & repair technicians, treatment planning, dosimetry, medical physics, nuclear medicine, PET-CT, mammography, mobile MRI, senior management...
Lots of choices if you're smart, hard working, and adaptable. But you'll need to get qualified and get a couple of years experience under your belt first