X-rays provide detail of the bone structures in the spine, and are used to rule out back pain resulting from:
- Instability (such as spondylolisthesis)
They image bones by shooting an x-ray beam through the body. The calcium in bone blocks penetration of the x-ray beam and the image of the bones is picked up as a shadow on a film positioned on the other side of the patient (see Figure 1).
X-rays provide for excellent bony detail because bone consists mainly of calcium. However, discs and nerve roots do not have any calcium, so an x-ray does not capture an image of these structures. An x-ray, therefore, cannot be used to diagnose lumbar disc herniation or other causes of nerve pinching.
X-rays should not be performed in women who may be pregnant.