Computed tomography (CT) of the head, neck and spine

Overview

In the Department of Neuroradiology, we use computed tomography to produce images of the head (brain, jaws, teeth, etc.), neck and spine. We apply the method in case of stroke, cerebral hemorrhage, tumors, skull base fracture, and to assist with surgical planning, or angiography (= imaging of vessels, e.g. for an aneurysm in the brain). The applications of CT are manifold and since today’s scanners no longer contain a narrow tube, but rather a wide ring, the procedure can also be used with people with claustrophobia.

Computed tomography provides quick and meaningful results and is a painless examination method that can usually be performed quickly. However, patients are exposed to a low degree of X-ray radiation. Therefore, always discuss with your doctor if the examination is really necessary or if they can offer radiation-free alternatives.

Our special examinations

In addition to general examinations of the head, neck and spine, we perform the following special examinations:

• Emergency radiology
• Head and neck imaging
• Advanced Neuroimaging

Advantages and disadvantages

Advantages

• Images are very accurate and detailed and almost all tissues can be imaged.
• CT provides very fast and meaningful examination results.
• Even patients with claustrophobia can undergo the examination.
• CT works even if you have a pacemaker or a metal implant.
• CT can be combined with other methods, such as angiography or positron emission tomography (PET-CT).

Disadvantages

• The patient is exposed to X-ray radiation, which is higher than during a conventional X-ray examination. However, physicians classify the radiation dose and the health burden as low. Moreover, the Department of Neuroradiology’s radiation safety certification means that we will take precautions to protect our patients from unnecessary radiation exposure. Therefore, we recommend a CT scan when the benefits of the examination outweigh the risks. Nevertheless, you should always discuss with your doctor whether the examination is actually necessary.
• The use of contrast media can lead to side effects, e.g. mild discomfort, a feeling of warmth or nausea. However, some people are hypersensitive or allergic to iodine-containing contrast media – even to the point of circulatory shock. This risk is lower for newer contrast media but nevertheless, always clarify potential intolerances before the examination. In case of kidney disease and hyperthyroidism, the administration of iodine-containing contrast media should be carefully evaluated before the examination.
• Computed tomography is not suitable for pregnant women because of the X-ray exposure. It is only used when no diagnostic alternatives are available.
• CT is more expensive than a conventional X-ray examination.

Course of treatment

Today’s CT scanners are no longer narrow tubes, but look more like a large ring. Most of the body lies outside the ring during the examination. This is a great advantage, especially for people with claustrophobia, because patients are not encased by a tube and have a clear view of the rest of the room during the examination.

Depending on the medical question, the total duration of a CT examination is about 15 minutes. The scan itself usually takes only a few seconds. The procedure is as follows:

• You lie down as comfortably as possible on the machine couch. Lie still during the examination, otherwise the images will be “blurred” and out of focus.
• Due to the X-ray radiation, you will be alone in the examination room, but you will be connected to the radiographer via an intercom and you can talk to them at any time.
• The couch is then pushed through the large ring via a rail.
• The X-ray machine rotates around your body. It scans the region of interest within a few seconds. Sometimes you will be instructed to hold your breath for a few seconds. In some situations, we will also use an iodine-containing contrast medium to see certain structures more clearly.
• A detector opposite the X-ray tube measures the radiation reflected by the various body structures. Depending on the tissue’s density, the signal is more or less attenuated. Bones, for example, have a high density and attenuate the rays more.
• A computer compiles the measured values and constructs a three-dimensional, complete image of the examined organ or structure. Tissues with different densities are displayed as different shades of gray.