I had x rays done in November that showed osteopenia. They then sent me for a dexa scan to have a better look and found it was osteoporosis (apparently they cant really tell much from the x rays but they do give a clue!) with a score of -3.7 whatever that means.
Currently on actonel to build them back up and undergoing tests to find out why, at 35, I have osteo.
If I had the time and energy I would campaign for DEXA scans for everyone showing symptoms of Osteoporosis, even if they have been diagnosed with AS etc. They scanned me too late and I am now at risk of fractures etc at an earlier age than I should be.