The National Osteoporosis Foundation says a test called Dual-energy X-ray absorptiometry,or DXA, is the best test for osteoporosis.

VOA: special.2010.08.31

But he says he felt the greatest satisfaction when a thirteen-year-old painted the word "gun" and then put a big "X" through it.

VOA: special.2009.06.01

After a few seconds, when the X-15 was safely away, the pilot started its rocket engine.

VOA: special.2010.07.07

In fact, he failed to recognize Planet X in a few photographs.

VOA: special.2010.07.11

A few became astronauts. The X-15 program lasted about ten years.

VOA: special.2010.07.07

It was covered in a new material called "inconel x."

VOA: special.2010.07.07

Three months ago, someone stole a letter from Madame X.

VOA: special.2009.12.26

Cappex.com -- c-a-p-p-e-x -- matches students with colleges and universities.

VOA: special.2009.02.26

The X-15 was a new idea.

VOA: special.2010.07.07

A less invasive procedure known as a virtual colonscopy is done with a CT scan that passes x-rays through a patient's abdomen.

VOA: standard.2010.04.07

But some doctors say the CT scan exposes patients unnecessarily to harmful radiation, as much radiation as a patient might receive from 400 chest x-rays.

VOA: standard.2010.04.07

It exposes a patient to much larger doses of radiation than the usual x-ray.

VOA: standard.2010.01.30