What side effects can an MRI have?

Summary

The invention of magnetic resonance tomography (MRT for short) represents an enormous enrichment for medicine. It not only enables the finest structures inside the body to be depicted with millimeter accuracy, but also has no harmful effects on the human organism according to current knowledge. This can be explained by the fact that, in contrast to X-rays or computed tomography (CT), no ionizing radiation (X-rays), but rather strong magnetic fields are used. For this reason, side effects in the investigation are very rare.

However, if symptoms arise as a result of an MRI, these are always due to the administration of a contrast agent. As a rule, the metal gadolinium or, in rather rare cases, iodine-containing contrast agent, such as is also used in X-rays or CT, is used for this.

The list of regularly occurring side effects is still manageable and ranges from Temperature sensation disorders and Tingling sensation on the skin over a headache, up to nausea.
More serious complications like allergic reaction on the contrast agent are extremely rare.

The pregnancy In order to definitely avoid any damage to the unborn child that has not yet been recognized, MRT examinations are performed on pregnant women only in exceptional cases carried out. Here is the Use of contrast media is not permittedwhich could get into the child's bloodstream via the placenta and leave permanent damage here.

Contrast agent / gadolinium

Function of contrast media

Even with an MRI, it is in some cases difficult to accurately assess certain tissues. This is due to the fact that some types of tissue, such as muscles and blood vessels, appear in very similar shades of gray on the cross-sectional images created by magnetic resonance tomography. This can be remedied by administering contrast media.

The metal is usually used for this Gadolinium used in its form bound to the acid DTPA, which is either used to represent the gastrointestinal tract swallowed or for showing other structures through a vein into the body's bloodstream injected and is then distributed throughout the body. Also strong blood supply Tumors or metastases can be so evident better represented become.

A few milliliters of the contrast agent solution are usually sufficient for this. In addition, MRI contrast agent is also many times as great better tolerated than the iodinated contrast agent, which is routinely used for x-rays or computed tomography (CT). However, this small amount can cause side effects in some patients.

Side effects

The most common side effects include a general malaise, Tingling sensation on the skin, a unusual feeling of warmth or cold, a headache or nausea. However, even these are very rarely observed. Since gadolinium is completely excreted via the kidneys within about an hour in healthy people, however, these side effects usually only last a few hours.

In extremely rare cases (around 4 in 100,000 patients are affected) it can also allergic reactions to the contrast agent come, which can then lead to life-threatening situations.

In rare cases it can iodinated contrast agent can still be used for an MRI. In this case a Thyroid over or - subfunction be excluded, otherwise dangerous side effects can occur.

nausea

In general, magnetic resonance imaging is a very gentle and side-effect-free examination. Nevertheless, patients repeatedly describe complaints during the examination. One of the most common side effects is mild to moderate nausea. However, this is not due to the MRI itself, but rather to the Administration of contrast medium, which is often necessary to better represent certain structures and organs.

However, it is usually quite easy to combat this nausea. So-called Antiemetics (from the Greek "anti" - against and "emesis" - vomiting) to which, among other things, the drugs Vomex® (Dimenhydrinate), Motilium® (Domperidone) and Metoclopramid® (MCP) belong. If symptoms such as nausea have already occurred during previous contrast media administration, antiemetics can also be given preventively before the magnetic resonance imaging so that nausea does not occur in the first place. In any case, it is advisable to inform staff present about any complaints when the nausea occurs.

a headache

Headache occurs as a side effect during MRIs usually immediately after the administration of a contrast medium on. It is important to know that most symptoms subside within a short time as a result of contrast agent administration. The contrast medium (in most cases "gadolinium" is used here) is used within half an hour to an hour Kidneys eliminated, so the Symptoms usually subside after a few hours.

What are the side effects of the MRI during pregnancy?

As far as we know today, magnetic resonance imaging has no effects on the human body and therefore no harmful side effects. Therefore, no harmful consequences are to be expected for the unborn child or for the adult. However, to possibly still today avoid unknown side effects, should have a magnetic resonance imaging during pregnancy yet only carried out in urgent cases become.

In any case not responsible is the gift of MRI contrast media in pregnant women. If contrast medium is necessary for the MRI to work, it must therefore be postponed until after the birth of the child.
Furthermore, breastfeeding women should Do not breast-feed for 24 hours after contrast administrationas the contrast agent can pass into breast milk.