A QCT test requires patients to undergo a CT scan where their lumbar spine bones are measured and their overall bone strength is formulated. A patient's history is taken to input into the computer and CT control panel. The patient lies on top of a liquid-type mat on the CT table and the table passes through the donut-shaped hole of the CT scanner. Images are taken, measured and results determined. The patient's actual examination time takes about 20 minutes.

The DEXA exam uses two x-ray beams of different energy levels to differentiate bone from surrounding soft tissue. It measures the bone mineral density at the lumbar spine and hip locations. The patient is positioned lying down on the table. There is an x-ray detector above the patient and the x-ray source is underneath the table. Starting at the foot of the table, a narrow x-ray beam is emitted from the x-ray source and moves in concert with the x-ray detector. Together these two units scan the length of the body to obtain the bone mineral density and forward the data to a computer. The patient’s total examination time takes about 30 minutes.

Women scheduled for a Bone Densitometry mineral density test should verify that they are not pregnant before taking the test. In addition, all patients should avoid taking calcium supplements 24 hours prior to the test.