<qa>  What is the DEXA scanner used to determine bone density?- DEXA scan: This test evaluates the strength of the bones in the back, wrist, and hip. The DEXA scanner uses low-energy x-rays to determine bone density. Scans are done of the lower spine, upper thigh, hip, and the entire body. For the test, the subject lies on the scanning table. Each scan takes about 3 minutes, and the entire procedure may take as long as 1 hour. 