Study proposes isotope analysis for earlier detection of bone loss - Are your bones getting stronger or weaker? Scientists at Arizona State University and NASA are taking on this medical challenge by developing and applying a technique that originated in the Earth sciences. In a new study, this technique was more sensitive in detecting bone loss than the X-ray method used today, with less risk to patients. Reference: 'Rapidly assessing changes in bone mineral balance using natural stable calcium isotopes,' Early Edition of the Proceedings of the National Academy of Sciences (PNAS), May 28.