MR angiography is also known as magnetic resonance angiography. It is a diagnostic imaging procedure that falls under the medical specialty of radiology. MR angiography is used to diagnose vascular diseases.
Here you will find further information as well as selected specialists and centers for MR angiography.
Angiography is the graphical representation ("graphie" from the Greek: graphein "to write, to carve") of blood vessels ("angio", also derived from the Greek, angeion = vessel).
Angiography is therefore an imaging procedure for visualizing blood vessels. It is usually used to diagnose constrictions or other vascular diseases.
The principle of all angiographic procedures is similar and is based on the administration of a contrast medium. Since blood and blood vessels can pass through X-rays and magnetic beams unhindered, a so-called contrast agent must be administered to visualize blood vessels. This dissolves and spreads in the bloodstream and prevents rays from passing through the vessel. This contrast medium then causes the rays to be extinguished, so to speak, which can be visualized. However, it is necessary to administer the contrast medium directly before the examination, as it is quickly excreted by the body.
Different techniques and devices can be used to image the blood vessels filled with contrast medium. The oldest method is conventional angiography, i.e. an X-ray examination in which a film is placed behind the patient. Depending on the amount of incident radiation, this changes color from black: unhindered passage of radiation to white: radiation is completely intercepted. Open vessels then appear as white tubular structures, so to speak, whereas constrictions or occlusions are black. The image is two-dimensional.
With the newer methods, computed tomography angiography (CTA) and magnetic resonance angiography (MRA), the examination is carried out using rings and tubes that can be rotated in all planes and therefore allow three-dimensional imaging.
The special thing about MR angiography is that it does not use an iodine-based contrast agent, but a much gentler one. It is therefore also permitted in the case of renal insufficiency. In addition, MR angiography does not use X-rays, but magnetic resonance radiation, which has significantly less harmful effects on the body.
MR angiography does not use harmful X-rays at all.
MR angiography is used on the following organs, among others:
If MR angiography is performed on the heart, the procedure is also known as coronary MR angiography. This allows coronary arteries, the heart muscle and also the large vessels that lead to the heart (vena cava) or branch off from it(aorta) to be visualized.
This examination is frequently used to visualize the coronary arteries in particular in order to show calcifications or impending blockages and, ideally, to prevent or optimally treat a heart attack. MR angiography can therefore provide important information about the presence of coronary heart disease (CHD), which is the main cause of a heart attack.
MR angiography can also be used to visualize the interior of the heart and thus assess its size and functionality. This may be indicated, for example, in the case of a pathological enlargement of the heart or heart failure (cardiac insufficiency).
Finally, changes in the heart valves, which are located between the right atrium and the right ventricle and between the left atrium and the left ventricle, can also be visualized. Changes in the valve to the aorta (aortic valve) can also be visualized, including leakage(aortic valve insufficiency) and narrowing due to calcification(aortic valve stenosis).
Using fluorescein angiography, the doctor can determine whether there is a disorder in the retina . In this case, no conventional contrast agent is used. Instead, a green dye is used, which is specially produced for this purpose.
Disorders of the retina in the eye can cause glaucoma and thus lead to blindness.
MR angiography of the brain
are visualized.
The examination is mainly used in cases of suspected
are performed.
MR angiography of the legs can provide indications of
may occur.
Before the examination, a detailed medical history (anamnesis) is taken. In particular, the following questions are asked:
During this consultation, you will also be informed about the examination. In particular, the benefits and risks are discussed in detail. As a patient, you have the opportunity to decide in favor of the examination or to ask about alternatives or to forego further examinations. If you are known to be claustrophobic, you should try out beforehand whether you can lie down in the tube and would like to have the examination carried out. Claustrophobia is the most common reason for the examination being canceled or not being carried out.
If consent is given, a cannula must then be placed in your arm. The contrast medium is then administered through this during the examination. In addition, in the event of complications, for example an allergy to the contrast medium (which is very rare), medication can be administered immediately to alleviate the symptoms.
Once the preparation has been completed, the patient lies down on the MRI machine couch. They are then pushed into the tube for the MR angiography. Once the patient is in place, the radiologist injects the required contrast agent via the cannula.
MRI devices use strong magnetic fields © digitale-fotografien | AdobeStock
The MRI machine now visualizes the affected blood vessel sections. Loud, knocking noises occur during this process. If desired, the patient can be given headphones beforehand, as the noises can be unpleasant.
MR angiography can take from a few minutes to around half an hour .
The image files are then processed and summarized using a computer. This makes the changes in the vessels that have been filled with the contrast medium particularly clearly visible.
As already explained above, claustrophobia is generally a contraindication for performing an MR angiography.
Furthermore, the MRI device works with strong magnetic fields. You must therefore state whether you have any metal implants in your body. These include
The most common side effects include a
Both can occur when the contrast medium is injected. However, once the injection has taken place, these side effects are no longer noticeable.
Contrast agent intolerance is rare. During preparation, the doctor clarifies whether the patient has an underactive thyroid gland or renal insufficiency. In these cases, the patient must not be given any contrast medium.
Other undesirable side effects include an inflammatory reaction in the area of the vein through which the contrast medium was administered. However, this is also extremely rare.
After the examination, patients should take it easy and drink plenty of fluids. This will help to eliminate the contrast medium from the body quickly. Also avoid heavy physical work.
Patients who suddenly experience
should consult a doctor immediately.
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