Magnetic resonance imaging (MRI)

How does magnetic resonance imaging work?

Unlike conventional X-rays or computer tomography, MRI does not use ionizing X-rays or radioactive radiation.
Instead, it is based on the use of strong magnetic fields and radio waves, which can produce high-resolution images of the inside of the body.

During the MRI examination, the patient is placed on a couch in a tubular MRI machine.
In this device, electric coils generate an intense magnetic field that aligns the hydrogen nuclei in the body cells – similar to a compass needle that is oriented to the north.
Radio waves are then sent through the body, temporarily changing the orientation of the hydrogen nuclei.
This change generates signals that vary by their differences in the tissues of the body.

These signals are recorded by the computer and converted into detailed images.
The images appear in different shades of gray depending on the type of tissue.
The MRI enables precise visualization of internal structures such as the brain, spinal cord, internal organs, muscles and joints.
The latest technology even makes it possible to visualize movements such as the heartbeat.

Contrast medium in magnetic resonance imaging

In some cases, a contrast agent is used in magnetic resonance imaging to improve image quality and show certain organs or tissues in greater detail.
Contrast agents are particularly useful in the diagnosis of tumors, the assessment of blood vessels or the identification of inflammation and other structural changes.
The contrast medium is injected intravenously into the bloodstream before the MRI examination.
It contains substances that influence the magnetic properties of the tissue and thus enable more precise delineation and highlighting of the structures on the images.
This makes it easier to recognize subtle differences between different tissues and potential pathological changes.

What preparations are necessary?

The following preparations are necessary for a safe and precise MRI examination:

• All metallic objects such as jewelry, watches, glasses, piercings, loose coins and clothing with metal parts must be removed before the examination, as they can interfere with the magnetic field and cause image errors.
• Please inform us of any medical implants such as pacemakers, defibrillators or inner ear implants.
  These must be checked for their suitability for MRI.
  Ideally, you should bring your implant card with you.
• Metal-containing intrauterine devices (IUDs) should be checked by a gynecologist after the examination.
  Other metal objects in the body, such as screws or splints, should also be reported.
• An MRI scan is generally safe for pregnant women if no contrast agent is used.
• Remove make-up, as some cosmetic products may contain iron particles that could distort the image.
  If you have non-removable piercings, please inform our medical staff.
  As a rule, however, the examinations can also be carried out with non-removable piercings.

How does the examination work?

Once all metal objects have been removed, the MRI examination can begin.
You will be given hearing protection or headphones at the start, as loud noises such as knocking and rattling occur in the MRI tube.
You will be in contact with our radiologist throughout the examination, both via the headphones and via an emergency bell.

You will then be pushed into the MRI tube on a couch.
It is important that you lie as still as possible during the examination so that we can obtain clear and precise images.
The examination itself is completely painless.

As you will have to remain in the MRI tube for some time, it is important that you lie comfortably.
If necessary, pillows can be used for support.
Depending on the area of the body being examined, the examination can take between 20 minutes and an hour.

For patients who suffer from claustrophobia or feel uncomfortable in the narrow tube, open MRI machines can be an alternative.
These machines do not consist of a closed tube, but of two large panes between which the patient lies and can look out.
If you have any concerns or fears about the narrowness of the MRI tube, please discuss this with our team of experts.
We offer our patients several options to make the examination more pleasant, such as listening to relaxing music via headphones or administering a sedative.

What side effects or complications are possible?

Magnetic resonance imaging is a safe and painless procedure, but as with any medical test, side effects or complications can rarely occur.

One possible problem is claustrophobia, which can be triggered in some patients by the narrowness of the MRI tube.
Dyes containing metal in (permanent) make-up or tattoos can also occasionally cause skin irritation, swelling or a feeling of warmth.

In very rare cases, mild hypersensitivity reactions may occur after the administration of contrast media.
These are usually treatable.
If such a reaction occurs, it is important to inform our medical staff so that a different contrast medium can be used if necessary, as the reaction is often due to certain ingredients and not to the main agent gadolinium.

In the past, nephrogenic systemic fibrosis (NSF) was a feared complication associated with the use of contrast media, but with careful use of cyclic gadolinium contrast media, this risk is hardly relevant today.

Pregnant women should be particularly careful, as the risk to the unborn child is highest in the first trimester of pregnancy.
For this reason, an MRI is only performed in the first three months of pregnancy in urgent exceptional cases.

What diseases can be detected with an MRI?

MRI is a particularly effective diagnostic tool for back pain as it provides excellent images of soft tissue.
This allows a variety of diseases and injuries of the spine and surrounding tissue to be precisely detected.

Herniated discs can be visualized in detail with an MRI.
In the event of a prolapse or herniation, these can press on nerve roots and thus cause pain.
The MRI can also clearly visualize changes in the area of the intervertebral discs, such as signs of wear or deformation.
Spinal canal stenosis, where the spinal canal is narrowed and exerts pressure on the spinal cord or nerve roots, can also be precisely localized and assessed.

The procedure also provides precise insights into diseases of the vertebral joints, such as inflammation or wear and tear of the facet joints, which often cause back pain.
Injuries to the spine, including fractures or other damage, are clearly visualized by the MRI.

MRI can also be used to detect and precisely localize tumours, both benign and malignant, in the area of the spine or spinal cord.
Infections of the spine or the surrounding tissue, such as spondylodiscitis, can also be easily visualized on the MRI images.

What is the difference between a CT and an MRI?

The main difference between computed tomography (CT) and magnetic resonance imaging lies in the type of imaging.
While CT slice images are generated using X-rays, MRI uses magnetic fields and radio waves.
Accordingly, both methods have different advantages and limitations.
One important difference is that CT examinations are associated with a certain amount of radiation exposure, while MRI has no radiation exposure and, provided precautions are taken, has no known side effects.

Is a CT scan just as informative as an MRI?

CT and MRI offer different strengths and applications, which is why they cannot be directly compared with each other.
CT is particularly suitable for quickly assessing bony structures and acute injuries.
It provides detailed images of bone fractures and other bony changes.
MRI, on the other hand, is particularly effective at imaging soft tissues such as intervertebral discs, muscles and nerves, making it ideal for assessing back and joint problems.

Although both procedures offer detailed imaging, their areas of application are not identical.
Which method is used depends on the question being asked and the medical context.

How much does magnetic resonance imaging cost?

The cost of a magnetic resonance imaging scan at the NUHR Medical Center varies depending on the type and scope of the examination.
The price can be influenced by factors such as the area treated, the examination technique required and the amount of work involved.
We will be happy to provide you with an exact cost breakdown and detailed information on the fees involved.