What should you know about CT bone densitometry?

A DEXA scan, also called bone densitometry, uses low-dose X-rays to compare bone density at selected sites such as the hip or spine. It is commonly used when a clinician is assessing bone strength or fracture risk. A CT scan instead produces layered images and may be chosen when the question concerns bone shape, a fracture, a joint, or another structure. Some centres offer CT-based bone-density measurements, but the exact method and purpose should be confirmed.

The report is interpreted with your age, medical history, previous fractures, medicines, and other risk factors. One result does not describe every bone or explain every source of back or joint pain.

Tell the imaging team if you may be pregnant, recently had contrast imaging, or have difficulty lying flat. Follow instructions about calcium supplements and clothing if the facility provides them. The scan itself is not a treatment. Take the result to the clinician who requested it so they can decide whether monitoring, lifestyle measures, or medicine is appropriate. Bisphosphonate therapy is one treatment that may be discussed for some people.

Bone densitometry is usually planned rather than urgent. Contact a clinician promptly after a new fracture, sudden severe back pain, loss of height with pain, or difficulty standing after a minor movement. Seek emergency care after a major injury, or for new weakness, numbness, or loss of bladder or bowel control.

Ask which test you are being booked for, which body sites will be measured, what the result means for your fracture risk, and when follow-up should occur.