X-ray Imaging

An X-ray (plain radiograph) is the simplest and most widely available imaging test. It produces a flat, shadow-like picture that shows the bones of the spine and their overall alignment. It is quick, inexpensive and easily accessed, and it remains a useful first look at the bony structure — for example after an injury, or to assess posture and alignment — even though it shows little of the discs, nerves or other soft tissues.

X-rays are a form of energy that passes through the body. Dense structures like bone absorb more of the beam and show up white, while softer tissues absorb less and appear in shades of grey. A detector on the far side records the pattern that gets through, creating the image. Because everything is projected onto a single flat picture, structures overlap, which is why X-rays are excellent for bones and alignment but limited for the detailed soft-tissue questions that MRI answers.

An X-ray is fast and completely painless. You stand, sit or lie against or in front of the detector while the radiographer positions you, and you keep still — sometimes briefly holding your breath — for a moment while each picture is taken. Usually two or more views are taken from different directions. The radiation dose from a spinal X-ray is low, though not zero, so you will be asked whether you are or might be pregnant.

X-rays give a rapid overview of the bony spine: alignment, the height of the discs (indirectly), signs of wear, and many fractures. They are often the sensible starting point and can be taken standing, which shows the spine under load. Their limitation is that they do not show the discs, nerves or spinal cord, so when those are the concern, MRI or CT is needed. Used for the right question, an X-ray is a fast, accessible and informative first step.

• —Royal College of Radiologists — iRefer: Making the Best Use of Clinical Radiology
• —UK Health Security Agency — Ionising Radiation: Patient Dose Information
• —British Association of Spine Surgeons (BASS)

This information is for general patient education and is not a substitute for an individual consultation. Always seek personalised advice from a qualified spinal specialist.