Prior to the introduction of the first dedicated bone
densitometry unit in the 1970s, physicians primarily used
one o f tw o methods to assess bone density. One was the
to ta lly subjective reading o f X-rays based upon individual
radiologist experience and the presence or absence o f
certain markers, such as the fine spicules, called
"trabecula, th a t form a network in cancellous bone."
While the absence o f trabecula may mean 30% to 50%
bone loss, it is fa r from precise. Clearly, a better way to
assess bone density was needed.