It is a painless imaging technique that uses a rotating beam of X-rays to create cross-sectional images of the lumbosacral spine. The lumbar spine is the lowest portion of your spine. The scan helps visualise the bones, joints, and the surrounding soft tissues of the lower back. Your doctor may advise this scan to find out problems such as herniated disk, multiple sclerosis, osteoarthritis, a pinched nerve, infection, and spinal surgery preparation.