Finding the right tests…
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Finding the right tests…
X-Ray
The lumbosacral, or LS, spine covers your 5 lower-back vertebrae down to where they meet the sacrum, and this is the most commonly ordered spine X-ray, usually reached for after simpler measures for lower back pain have not helped over several weeks. Taken from the front, this view shows the width, spacing, and side-to-side symmetry of these bones, along with the traverse processes that stick out from each vertebra. Doctors generally order this after pain has lasted beyond four to eight weeks, follows an injury, appears in someone older, or comes with signs pointing toward nerve involvement, rather than at the very first visit for ordinary low back pain.
This front-facing image of the lower back shows vertebral width, the alignment of the spinous processes, and whether the transverse processes and pedicles look symmetric on both sides. It also shows the disc spaces from this angle, though a side view gives a clearer read of how narrow they actually are.
Lower back pain is common, but most doctors do not order an X-ray at the first visit. Imaging is generally saved for pain that has lasted beyond four to eight weeks, followed an injury, occurs in an older adult, or comes with signs of nerve involvement such as leg weakness or numbness.
Taken straight through the front, this view is well suited to checking whether the vertebrae line up evenly side to side and whether the bone width and transverse processes look symmetric. Traumatic changes to the vertebral body and disc spacing are also reasonably well seen from this single angle.
An X-ray, including this one, cannot diagnose sciatica, a herniated disk, or spinal stenosis on its own, since these involve soft tissue and nerves that bone imaging does not picture. If leg pain or numbness continues after a normal-looking film, your doctor may move on to an MRI.
Most low back pain gets better on its own, so doctors generally wait unless pain has lasted several weeks, followed an injury, or comes with nerve symptoms. This avoids unnecessary imaging for pain likely to resolve anyway.
Not directly. Sciatica usually involves a nerve being pinched by soft tissue, which an X-ray cannot picture, so an MRI is typically used if the cause needs confirming.
It checks whether the lumbar vertebrae are lined up evenly side to side and whether the bone width and processes look symmetric. A side view is added separately if height or disc spacing needs a closer look.
Yes, lumbosacral spine X-ray is the fuller name for what is commonly called a lower back X-ray, covering the lumbar vertebrae and the top of the sacrum.
This page is general information about the test, not medical advice. Your own report's reference ranges apply — please discuss your results with your doctor.
You may be asked to lie in more than one position, and the technologist will guide each one. The whole appointment is usually brief.
Yes, mention any prior spine surgery, screws, or rods beforehand, since these appear on the image and help the radiologist read the film correctly.
This view includes the lower back, which the CDC notes as an area that may expose a fetus to radiation, so tell your doctor and the technologist first so they can advise you.