OP - I know it depends on finances, but the government are allowing second degrees in scientific based areas. Lots of people do a degree at 18, then go on to study nursing/midwifery at a later date.
I would strongly suggest if it's viable, also if you have the time, to write in and ask for work experience. You could do one morning a week, asking to cover X-Ray's, ultrasounds, radiotherapy, CT scans and MRI scans. It would make you stand out from others.
Also see if there's any journals out there on radiography, or maybe just google latest radiography news, so you show your interest, selecting articles of interest you can discuss with your opinion of the positives and negatives.
You could do it as a Year 0 or as an Access Course. Year 0 would mean funding for that first year along with a higher chance of being selected, as you're studying a gateway course initially.
I'm old and archaic, I don't think you're ever too old to pursue your passion. That's the thing about work, you want it to be something you enjoy, rather than a countdown till Friday.