Computed tomography (CT) is used when magnetic resonance imaging (MRI) cannot be used on a patient for medical reasons (for example, due to a pacemaker or inner ear implant). This imaging examination method also offers additional information about bone changes in the spine and provides a higher degree of valuable information in pre-operated patients with metal implants.
At the beginning of the examination, the patient usually lies on their back on a table that passes into the circular scan gantry of the CT scanner. The section of the spine that is being examined is recorded in cross-sectional images (slices) and displayed in all spatial directions. This results in a large number of measured values that are transformed by computer into image information with very good bone and good soft tissue differentiation.
While conventional X-ray technology only produces two-dimensional images, computed tomography depicts the inside of the body as a cross-section that can be viewed free of superimpositions. This depth of display allows details down to one millimetre in size to be recognised. This technique has become an indispensable tool today and is further improved by three-dimensional reconstructions (for example, of the vessels).
Furthermore, compared to MRI, CT offers more direct bone imaging, which can be useful for diagnosing certain bone diseases (for example, degenerative changes).
No preparations are necessary for CT scans of the cervical, thoracic and lumbar spine. The examination takes about 20 minutes.