How Does a Dexa Scan Work?
DEXA is an acronym for Dual Energy Absortiometry. This painless test measures bone mineral density in patients at risk for osteoporosis by directing low doses of x-ray energy from two different sources toward the patient’s bone. Each x-ray beam has a distinct energy peak or signature. Tissue absorbs one of the beams and the bone absorbs the other energy beam. Then the scanner can read the different levels of absorption and uses special software to measure the bone mineral density, which is an indicator of bone strength. The hip and spine are the usual areas for the scan but fingers, hands, forearms or even the foot provide suitable readings as well. To perform the scan, the patient lies down on a table. Below the table is an x-ray generator and above the table is an imaging device. The imaging device passes over an area of the body and generates an image on a monitor. Images of the spine require the patient to elevate her legs by resting both legs on a support pad. This position causes
