Introduction
If a stroke is already suspected (e.g. by the clinical FAST test), an immediate, emergency diagnosis must be made to substantiate the suspicion – the subsequent therapy depends on the cause of the stroke. For this purpose, a CT is primarily used for imaging; if more precise results are required, an MRI can also be consulted. The CT or MRI can then be used to differentiate whether the cause is a cerebral haemorrhage or a vascular occlusion. To clarify the cause of a vascular occlusion, further examinations are then usually carried out.
Diagnostic steps of a stroke
The first suspicion of a stroke is made by a characteristic clinic, i.e. on the basis of certain symptoms which can be determined by means of the FAST Test. Once the suspicion has been established, it must be investigated as quickly as possible whether the cause of the stroke is a cerebral haemorrhage or an occlusion of cerebral vessels. This is important because in both cases, the respective emergency therapy differs significantly.
If there is a suspicion, it must be investigated as soon as possible whether the cause of the stroke is a cerebral hemorrhage or an occlusion of cerebral vessels. This is important because in both cases the emergency treatment differs significantly. The FAST Test is a possibility for a quick initial diagnosis of the stroke.
FAST stands for face (face), arms (arms), speech (language) and time (time) and combines all the major symptoms of a possible stroke: a hanging corner of the mouth (unilaterally paralyzed mimic muscles) in the face, unilateral paralysis of the arm (it can no longer be lifted completely) and a blurred speech or even the inability to speak. The T for time stands as a reminder that in the event of a possible stroke, every minute counts and that further diagnostics with rapid therapy initiation must be carried out immediately. In a head CT, the brain is depicted in thin layers by X-rays.
With the help of these layers, information can be provided as to what caused the stroke – whether a cerebral hemorrhage or a blood clot in the vessel prevented the blood supply to a specific area of the brain. An extended possibility is also a CT angiography, i.e. a special vascular imaging of the brain in the CT, as well as a CT perfusion, which is a special blood flow measurement of the brain. For this purpose, a contrast medium is administered via the veins, so that the brain vessels can be displayed more clearly and circulatory disorders can also be detected more easily.
The CT examination is carried out to quickly determine the cause of the stroke, since the treatment options for a stroke differ depending on the cause. We therefore recommend our site to you:
- Causes of a stroke
- Therapy of a stroke
An MRI of the head is also an image of the head or the brain in thin layers, but unlike a CT, no X-rays are used here. The image is generated with the help of a strong magnetic field and electromagnetic waves.
The MRI enables a fairly accurate depiction of the stroke and this also earlier than a CT, which is why it is also used for early diagnosis or for more precise clarification. One disadvantage is that an MRI takes much longer to perform than a CT and is also much more expensive. This is the reason why MRI is therefore not usually used directly as the first examination method for emergency diagnostics in the event of a stroke.
If the onset of the stroke is unclear or cannot be determined by the person affected, MRI is usually preferred, since emergency treatment cannot be initiated anyway. Once the cause of the stroke is known, the therapy can be started. Depending on the cause, this varies.
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