Procedure | Examination of the skull and brain using MRI

Procedure

After all metallic objects have been deposited, magnetic resonance imaging can begin. The normal examination device is designed as a tube into which a couch can be inserted. The patient lies down on this couch and his head is moved into the tube.

Patients suffering from claustrophobia are given a sedative before the examination. Since very loud technical knocking noises occur during the examination, the patient is given either sound-proof headphones or earplugs through which music can be heard. In addition, the patient is given a switch in his hand which he can press to call the medical staff.

The medical staff leaves the room during the examination and takes a seat behind a glass pane. The medical-technical radiology assistants can observe the patient from here. Depending on the purpose of the examination, it may be necessary to take a series of images with contrast medium in addition to the normal MRI examination.

This must then be injected into the patient in between.When the examination is completed, the patient is moved out of the tube on the couch and has no further precautions to take. An exception is made if the patient has been given sedatives before the examination. Then he is not allowed to drive a vehicle on this day.

The images are evaluated by a radiologist and the patient is then asked to come for a consultation. The actual MRI examination of the head takes about 15 to 20 minutes. In addition, there is waiting time, preparation time, patient positioning and the subsequent final consultation. Depending on whether the MRI is performed with or without contrast medium, additional time must be planned for this. For all preparatory and follow-up measures and the head MRI, you must allow between 60 – 75 minutes.

Contraindications for an MRI

For patients with a pacemaker or with an implantable defibrillator (ICD), an MRI examination cannot be performed in most cases. MRI should also not be performed on other metallic foreign bodies, such as mechanical artificial heart valves, as otherwise both the patient and the implant may be damaged. Insulin pumps and an artificial inner ear (cochlear implant) are also contraindications to MRI.

In the meantime, however, there are also pacemakers suitable for MRI, but the attending physician should still be informed about these in the preliminary consultation. In addition, there are limitations that should not be avoided by using magnetic resonance imaging, but the administration of contrast medium. These are a functional impairment of the kidney (renal insufficiency) or pregnancy in the first three months.

and MRI in pregnancyIn MRI imaging of the head, the skull and neck are fixed with pillows and special frames. In addition, a coil is placed around the head to record the radio waves required for imaging. This makes the tube, which is normally 60 to 70 cm wide during MRI imaging of the head, appear even narrower.

If necessary, the patient can be given a sedative before the examination. In addition, the patient is given a button in his hand which he can press during the examination if his discomfort increases. In exceptional cases, an examination in an open MRI is also possible as an alternative. This is a C-shaped magnet that allows the patient to look around during the examination.