A lumbosacral spine x-ray is a picture of the small bones (vertebrae) in the lower part of the spine (the lumbar region) and the sacrum, the area that connects the spine to the pelvis.

The test is done in a hospital radiology department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray table in different positions. If the x-ray is being done to diagnose an injury, care will be taken to prevent further injury.

The x-ray machine will be placed over the lower part of your spine. You will be asked to hold your breath as the picture is taken so that the image will not be blurry. Usually three to five pictures are taken.

Inform the health care provider if you are pregnant. Remove all jewelry.

There is generally no discomfort associated with an x-ray, although the table may be cold.

Lumbosacral spine x-ray helps evaluate back injuries and persistent numbness, low back pain, or weakness.

The test will detect abnormalities such as fractures, dislocations, osteoporosis, and deformities in the curvature of the spine. The test may also detect bone spurs, disk problems such as herniated disk, and degeneration of the vertebrae.

There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most experts feel that the risk is low compared with the benefits.

Pregnant women and children are more sensitive to the risks of x-rays.

There are a number of back problems that an x-ray will not detect because they involve the muscles, nerves, and other soft tissues. A lumbosacral spine CT or lumbosacral spine MRI are better options for soft tissue disorders.