Imaging techniques for back pain
Usually these methods are sufficient to find out the reason for the back pain. In some cases, however, a more extensive diagnosis is necessary. For this purpose, the various imaging procedures are available.
The standard is first of all the X-ray. This is not very stressful for the patient and already gives the doctor a good insight into whether there are any abnormalities in the spinal column. More complex, but also more informative, are CT and MRI.
In these procedures, either with or without contrast medium, sectional images of the thorax are taken so that bony structures as well as soft tissues and nerves can be assessed well. A contrast medium should only be used if there is a well-founded suspicion of an existing inflammation or tumor, because it exposes the patient’s organism to additional stress and quite a few people are allergic to contrast media. Another area in which contrast media can be used is so-called myelography, which is performed when a pathological process within the spinal cord itself is assumed.
Here, the contrast medium is injected into the area where the nerves leave the spinal canal. Sometimes a blood test can also be useful, as it can provide information about whether there is an inflammation or a tumor in the body by means of certain parameters. However, one should be careful not to start too lightly with a pronounced apparative diagnosis.
Many people have findings that differ significantly from the norm, but which are by no means the cause of back pain. However, if these are misinterpreted as the cause, a long, stressful therapy may follow, which is not only unnecessary, but also does not bring about any improvement.Since this first result has been “rushed”, the actual cause of the pain often remains unidentified. In such cases, this is often due to psychological reasons or simply to bad posture and the resulting tension, and these problems are then not addressed at all.
In the case of back pain, an X-ray image can be helpful if there is a suspicion that the cause is in the bones. If, for example, scoliosis, i.e. a faulty curvature of the spine, is the cause, an X-ray diagnosis is always necessary. This is important to determine the extent of the scoliosis.
X-rays are also well suited for so-called functional images, e.g. images taken in a forward and backward bending position. However, for the more common causes, such as herniated discs, an X-ray is not necessary. It should never be performed without sufficient reason, i.e. without a proper indication, because the radiation exposure should not be underestimated.
A magnetic resonance imaging, i.e. an MRI, is a very helpful method when it comes to assessing possible so-called soft tissue damage to the back. The most common of these is a herniated disc, for which an MRI is the best option for detection. The MRI shows muscles and ligaments in particular very well.
Usually only parts of the spine are examined, depending on where the pain is located. If, for example, pain is located in the lower back with suspected herniated disc (this is the most common region in this region), an MRI scan of the lumbar spine is initiated. Before an MRI scan is taken, it should be carefully considered whether it is necessary.
Due to the long duration of the scan and the noise exposure, it represents an unpleasant situation for the person to be examined. Therefore, it is a guideline that an MRI scan should only be performed if the back pain is still present after about 6 weeks and no cause has been found. Of course there are exceptions to this rule, which should be discussed with a doctor.
Especially if there are signs that indicate incarceration, such as prolonged numbness in one leg, an MRI should be performed earlier. A computed tomography, i.e. a CT, of the spine is often done in cases of back pain when there is a suspicion of a fracture of one or more vertebral bodies. In the case of a herniated disc, a so-called follow-up is often required to check whether the tissue recovers after a certain time, usually under therapy.
Here, too, a CT is usually used, since this type of imaging is much faster and less time-consuming. For most types of back pain, a CT image does not require a contrast medium. Myelography is a procedure in which contrast medium is first injected into the spinal canal and then an X-ray image of the spine is taken.
This allows the spinal cord and especially the surrounding sheath, the so-called spinal canal, to be depicted particularly well. Today, myelography has declined due to the availability of MRI and CT images. However, if the back pain is caused, for example, by a blockage in the spinal canal, myelography can be helpful for precise localization and size estimation.
In most cases, this imaging is usually performed after another image that did not provide sufficient information. In a discography, contrast medium is injected into an intervertebral disc and then x-rays are taken to observe how it spreads. The person being examined is slightly anaesthetized.
Back pain is often caused by intervertebral discs, i.e. by bulges or displacements. This type of pain is usually caused by pressure from the intervertebral disc on the nerves exiting the spinal cord. Discography is an invasive type of diagnosis and therefore should only be performed when it is clearly necessary.
