Preparation

No special preparation, such as sobriety or laxation, is necessary before an MRI examination. In the run-up to the examination, an informative talk is held in which the doctor explains the course of the examination to the patient, inquires about his/her state of health, points out risks and gives the patient the opportunity to ask questions. Before the examination is performed, the patient must remove all metal-containing parts.

These could be attracted by the strong magnetic field generated during the examination and cause serious injuries. These include, for example, jewelry, metal parts on clothing, keys, money and credit cards, glasses, braces and dentures. Metal parts that are in the body, such as surgically inserted screws, wires or joint replacements, artificial heart valves and also tattoos with metal-containing colors must be announced before the examination. In the examination room, the patient must lie down on a couch and is usually given headphones to muffle the loud knocking noises that the examination device produces.

Contraindications

As a rule, magnetic resonance imaging cannot be performed on patients with pacemakers or implanted defibrillators (ICDs), since this can lead to damage to the implants and the patient. This also applies to patients with built-in insulin pumps or inner ear implants (cochlear implants).

Implementation

The duration of an MRI examination depends on what needs to be examined and how many images need to be taken. As a rule, magnetic resonance imaging takes about 15 to 30 minutes. If a contrast medium has to be administered, the examination can also take longer. In addition, the waiting time and preparation time should be planned.

Contrast medium

Since some tissues, such as muscles and blood vessels, appear quite similar on MRI images, some examinations require the use of a contrast medium that allows the structures to be better distinguished from each other. The administration of a contrast medium also makes it easier to identify inflammation foci or tumors. As a rule, the contrast medium is injected into an arm vein during the examination.

A contrast medium containing no iodine is used, which is generally very well tolerated. Only very rarely do allergic reactions occur. However, it should not be used in patients with kidney disease.