A lumbosacral spine X-ray is done by the lab technician on order from the doctor.
Lumbar spine consists of five vertebral bones and the thoracic spine also rests on the lumbar spine including:
Nerves
Large blood vessels
Cartilage
Tendons
Ligaments
Small amounts of radiation are used to take an image of your internal body. The X-ray helps the doctor in viewing if there is any internal injury, bleeding, abnormality or any disease affecting the bones.